Tenser's Skystrider - build your own bomber plane at level 1 using core rules

[Renduaz]

....Under raging storm clouds, the vampire Count Strahd von Zarovich stands silhouetted against the ancient walls of Castle Ravenloft. Rumbling thunder pounds the castle spires. The wind’s howling increases as he turns his gaze down toward the village of Barovia from his balcony. A servant approaches, momentarily distracting him: "Uhh, boss. I saw something weird above us, I think you should take a look at this." The count looks up, his eyes widening, as a massive silhouette plummets through the clouds at immense speed, directly above the castle. Somewhere, thousands of feet above Barovia, a maniacal laughter echoes through the air.

Here are the instructions which should hopefully, if your DM doesn't shut this ploy down before you become the realm's Lenoardo Da Vinci, which should enable you to create Tenser's Skystrider, using nothing but core rules, level 1 ritual casting and spells, and some relatively cheap materials. Illustration below.

i.imgur.c(o)m/zO1L4Di.png

1.Obtain the perquisite materials: A tight, closable, preferably metallic yet thin shell-like two pieces container which is at least 3 feet in diameter and 3 or more feet in length as pictured, with a handle and pulley attached somewhere at the bottom, and a pole with a similar mechanism coming out of the upper shell casing. Also advisable to have some kind of hatch on top of it or way to see down to the disk. A lightweight seat of any kind, with a strong belt or something else to strap yourself to, and two hoops at the back that one could secure a chainlink to. 2, 20-30 feet long chainlinks or other durable material cords. A block and tackle optionally.

Note - If this all seems very complex to you, there's a good reason. There are a numbers of "Using Tenser's Disk as a flying device" methods for previous editions that no longer work ( I.E designs which relied on the ability to direct the disk, no longer available ), and it's also intended to apply to the strictest interpretation of Tenser's Floating Disk per 5e rules )

2.Place the lower shell casing, and cast Tenser's Floating Disk on it, as pictured in the first step. The lower shell case will become the disk's "ground" reference, since "ground" is defined in 5E as practically any material surface. If you're on the second story of a house, then that's your ground, not the first story, if you're on a bridge, it's your ground, if you're on some floating platform, it's your ground too. If you have reservations about that, just get on some bridge and attach your lower shell surface to it, then cast the disk on that. After all, it's no different than the bridge itself, or from a house foundation. Now take the upper case of your shell, place it on top tenser's disk ( This will register as an object being carried by the disk, as it's meant to ), and fasten it to the lower casing through whatever locking mechanism you may have ( Bolts, sliding space, wrapping it around with chains and an actual lock, anything ) and Tenser's Disk is now carrying it's own shell, doing precisely what it's supposed to do, which is carrying things, as shown in step 2. Now, for convenience if it's bound to you, perhaps have someone else attach the 20-30 feet chains ( or ropes, if you want ) to some sort of pulley or similar mechanism coming out of the shell at the locations pictured and from there fasten to your seat with a strong strapping belt through hoops or anything else. Make sure they're stretched tight so the seat is suspended and balanced properly.

3.Strap yourself to your seat, and possibly have someone else move it forward from you, until you're more than 20 feet away from the disk, and the chainlinks or ropes are stretched. At this point, since the contraption doesn't weigh anywhere near 500 pounds, and the disk starts following you, it should propel it forward by moving the upper shell on top of it, thus in extension the lower shell as well, and therefore the chains as well as the seat, keeping it in perpetual motion. In order to fly upward, cast mage hands ( Or figure out a different way ) which has a range of 30 feet and can be done infinitely, and use the uncoiled stretch ( If you have 25 feet chains, then it's gonna be 5 feet length of chain for instance ) of chain you have left to tilt the seat slightly upward ( Pull back upper rope, extend lower rope for example ) or downward. You may also definite want to add another 2 mechanisms like this coming from both sides ( or handles ) of your seat hooked to the sides of the shell, for steering left or right. Now, the usefulness of the "shell" is that according to Tenser's Disk spell description, it can't cross an elevation change of 10 feet or more from it's ground reference. So it's a good thing it's ground ( The lower casing ) is always at the same place below it, attached to the upper casing that it carries, isn't it?

4.Before taking off, you might want to cast another Tenser's Flying Disk right next to the encased one, and use Block and Tackle or any other means to lift up about 499 pound worth of rock or something else, while keeping something that weights 1 pound on your person ( Or alternatively, you could just let that disk dissipate instead of renewing it ). It should move along your Skystrider.

5.Every 30-40 minutes when the disk is going to expire ( 1 hour duration ), just cast another one using ritual form, which takes 10 minutes and doesn't extend a spell slot, and you can do it infinitely. It's also within your range ( 30 feet casting range for Tenser's Flying Disk ). If you need a line of sight, just use mage hands or something else to open any kind of hole or hatch to see inside the shell when looking back. You might also be able to carry another party member on the middle of the disk itself since it probably won't exceed weight limit. And if it's someone who can cast it too, you might be able to deliver even more payload in other bombing disks.

Advantages and disadvantages over other forms of flight

Fly/levitate spells - Infinite duration, lower level. Possibly much slower ( There are no rules for how fast the disk moves when you're more than 20 feet away from it in 5e )

Using your flying familiar to cast the disk - Unclear rules. Says "When you cast a spell with a range of touch, your familiar can deliver the spell as if it had cast the spell." ( Disk has a range of 30 feet, although can probably be cast at touch distance? Does that work in the first place or apply to familiar rules? ). Can familiar cast a ritual?

Using Disk and Druid with flying wild shape to guide it - Higher level, might not have a druid at your party. Perhaps you need to go on your own.

Flying mounts - Probably much higher level, and height limit for the beasts?

That's pretty much all for this thread, except I have to state that I really haven't optimized this build very much, since I was mostly trying to come up with a way to adhere to 5e rules of the spell and game definitions as strictly as possible. Remember for instance, that the ground you cast Tenser's on must afterwards move along with it, since anything else would prevent the spell from changing elevation. Furthermore, the disk is just a plane of force, you can't stick anything to it or drill in it, the only thing it does is carry. So any contraption must fit around the whole disk. And then, you can't make anything which is classified as an obstacle to the disk. It has to be something the disk moves by carrying, not by exerting pressure on. And that's why the shell design is the most perfect I could figure. I urge everyone to post improvements and ideas to the existing design though, or better alternatives for flying devices if you can think of them.

[Garresh]

You're doing Pelor's work, son.

[Renduaz]

You're doing Pelor's work, son.

Thank you very much.

[Arenabait]

You are a god among men.

[King539]

Please dumb this down for a moron like me. Please.

[Steampunkette]

Forgive the pun... but that wouldn't fly in one of my games.

The ground is not "whatever is under you". The ground is the ground.

[Hrugner]

Please dumb this down for a moron like me. Please.

You cast your floating disk inside a giant pocket so it carries the "ground" with it. You also attach a chair to the pocket that puts you 30 feet away from the disk so that the disk moves toward you. since the chair is attached to the disk/pocket, the disc pushes you out of its reach while chasing you.

At my table we've ruled that you can't take the ground with you, but you don't need the chair contraption to get the thing to move around at your own speed while riding it.

[Renduaz]

Forgive the pun... but that wouldn't fly in one of my games.

The ground is not "whatever is under you". The ground is the ground.


You cast your floating disk inside a giant pocket so it carries the "ground" with it. You also attach a chair to the pocket that puts you 30 feet away from the disk so that the disk moves toward you. since the chair is attached to the disk/pocket, the disc pushes you out of its reach while chasing you.

At my table we've ruled that you can't take the ground with you, but you don't need the chair contraption to get the thing to move around at your own speed while riding it.

House rules are yours to make of course, but let me just clarify how the device is totally compatible with the core rules reading. Steampunkette, the core books ( Traps, tracking ,etc.. ) specifically classify almost any soild surface as a ground. Assigning "ground" only to the earth soil if that's your intention is actually contrary to the rules and breaks the games. Because then dungeon floors aren't ground, house floors aren't ground, bridges aren't ground, etc.. That means you wouldn't be able to let someone cast Grease or Tenser's or any ground spell unless they were on the earth's soil. Or if they're stepping on a patio or fighting on a ship or whatever.

Hrunger's house rule is more compelling, although there isn't any hard prohibition on "taking the ground with you" ( It's actually the disk taking it's own ground essentially ) in the books. A hot air balloon's basket would probably count as a "ground" which you also take with you along with the balloon, and it also remains at the same place at any altitude. Likewise with any kind of floating surface which is being held by magic. As for not needing the chair contraption, which method are you using to ride the disk? Since the spell description states that the disk remains immobile as long as it is within 20 feet distance of you.

[Stan]

Forgive the pun... but that wouldn't fly in one of my games.

The ground is not "whatever is under you". The ground is the ground.

Yea, there's nothing in the spell that designates a particular piece of ground (in the shell) to be "the ground" or the only piece of ground the spell reacts to. Therefore, the disk will stay 3' off of whatever solid surface is nearby, and not raise into the air. Conceivably, if you had a stone floating in the air far from the ground and then cast the spell on that stone, the disc would act as if that's the ground, The image link doesn't work so I'm unclear but I don't think chains are going to work - it's moving towards you so the chains would go slack. It can't pull you for the same reason. Theoretically, you could have a 25' bar or pole between you and the disc spell. But you have to restrain the disc first to get it to stay 25' while everything is attached. Mage hand is also too weak to have much effect on a person or a sizable chunk of earth.

[Renduaz]

Yea, there's nothing in the spell that designates a particular piece of ground (in the shell) to be "the ground" or the only piece of ground the spell reacts to. Therefore, the disk will stay 3' off of whatever solid surface is nearby, and not raise into the air. Conceivably, if you had a stone floating in the air far from the ground and then cast the spell on that stone, the disc would act as if that's the ground, The image link doesn't work so I'm unclear but I don't think chains are going to work - it's moving towards you so the chains would go slack. It can't pull you for the same reason. Theoretically, you could have a 25' bar or pole between you and the disc spell. But you have to restrain the disc first to get it to stay 25' while everything is attached. Mage hand is also too weak to have much effect on a person or a sizable chunk of earth.

The rules designate it as such. There was actually a thread on this forum, "Disciple Of Tenser" which mentioned how the ground is ruled by the handbook to be any kind of solid material surface ( And also had a flying device which is now defunct in 5e, however definition of ground remains the same ), and that saying otherwise creates discrepancies. In relation to what you say, you could easily just raise the lower shell casing 11 feet above ground, then since the disk can't cross a 10-feet elevation, the lower shell would become it's ground reference. Furthermore, in the spell description itself, there's a passage that says "It can more across uneven terrain, up or down stairs, slopes and the like". Now, if Tenser's Disk moves up stairs so that it is floating 3 feet above them as soon as it encounters them, that means Tenser's Disk does in fact use whatever "particular" piece is directly underneath it at any given time to designate it's ground, otherwise it would get suck when going up the stairs. So if I put a 3-feet diamater shell below it, then it will always hover 3 feet above it. And if I raise it ( Like a stair is raised in a staircase ), then Tenser's will adjust itself and remain at 3 feet above the particular section of ground that it's hovering above at the given moment. That is the only way to read it.

I'll repeat, let's say you have a couple of stairs going up, which are all part of a single staircase. 1 stair is 6 feet tall, the next stair is 6.5 feet. The spell description explicitly says that the disk will move up and down stairs, so when it's on the 1st stair, it will be 9 feet off the bottom of the staircase structure. When it's on the second stair, it will hover 9.5 feet above the bottom of the staircase. If some giant rips the staircase apart and lifts it up, Tenser's disk will start rising along with the stair that it's hovering above. But all stairs are still part of the same staircase, so it's clear Tenser's Disk hovers 3 feet above a particular area. Even slopes won't make sense otherwise, since slopes are essentially a particular piece of ground, a bunch of soil packed up, no different than any other kind of material placed on the ground.

And as for the chains or ropes, they're supposed to be stretch tightly. Think a chair which is 25 feet away from the shell, and 30feet length of chain. Now, chain is attached to some kind of pulley wheel, so that 5feet remains inside the wheel, while the other 25 feet are stretched completely firmly between the shell and the chair. You just have to remove the (o) from the "com" in the image link and replace it with o to make it work. Restraining the disk while you build the contraption is easy, you just have someone else do everything while you stay within range. And mage hand is only needed to to use the pulley and open the hatch.

[Corginin]

I just had my owl familiar drop a necklace of fireball while playing Flight of the Valkyries, but this sounds much more fun!

[Stan]

The rules designate it as such...

You missed the thrust of my counterpoint. Sure, the shell is ground, though it's very unclear how big it would have to be to be considered ground in it's own right. But it's not the only ground. Why would the disc ignore the rest of the world just because it's in a metal box? Is the shell sitting on the ground when the spell is cast? Why is the disc positioning itself relative to the shell and not the ground under the shell? (calling a bridge ground doesn't help as the disc would be positioned relative to the ground of the bridge, not the shell)

The diagram didn't help me, I'm still confused by part 3. When the shell comes towards you, how does that move you at all?

[JackPhoenix]

The rules designate it as such. There was actually a thread on this forum, "Disciple Of Tenser" which mentioned how the ground is ruled by the handbook to be any kind of solid material surface ( And also had a flying device which is now defunct in 5e, however definition of ground remains the same ), and that saying otherwise creates discrepancies.

Citations needed

Also, as Stan noted, pulleys, ropes and gravity don't work the way you think... the chair would be sitting on the ground, though tied to the ropes which won't stay taut. At best, you could sit on the chair, pushing yourself on the ground, looking like a fool in the process... and you still wouldn't fly, meaning it was all pointless.

[Renduaz]

You missed the thrust of my counterpoint. Sure, the shell is ground, though it's very unclear how big it would have to be to be considered ground in it's own right. But it's not the only ground. Why would the disc ignore the rest of the world just because it's in a metal box? Is the shell sitting on the ground when the spell is cast? Why is the disc positioning itself relative to the shell and not the ground under the shell? (calling a bridge ground doesn't help as the disc would be positioned relative to the ground of the bridge, not the shell)

The diagram didn't help me, I'm still confused by part 3. When the shell comes towards you, how does that move you at all?

I did answer your counterpoint with the stairs passage from the spell description. According to the spell itself, it does ignore the rest of the world and all other ground as long as it hovers above, at the upper limit, a particular ground which is equal or greater than the disk's diameter. Apparently it does so even in much smaller ground sections since it can move up stairs. So if you pile up some earth to a slope, the disk hovers 3 feet above that slope, as long as it's there, it doesn't care that the rest of the ground is lower. And likewise if you put a wooden block on the ground and cast the disk on it, it will hover above the block as long as it's in the same spot. Or if you have staircase, it will be elevated 3 feet above whatever stair it's currently on, without caring about the other stairs or the base of the staircase.

So actually we don't really know just how small something can be before the disk ignores it for example, but that's irrelevant to my device, since we can clearly deduce from the rules that a 3-feet in diameter metal sheet will be more than enough to sustain the disk at a height of 3 feet above it. And it's also understood from the spell description ( stairs, slopes ) that the disk hovers 3 feet above whichever solid surface is beneath it at any given moment, regardless of any other factors. So if you put down a 3-feet diameter metal circle somewhere and cast the disk on it, the disk will float 3 feet above it, and if the metal circle goes up, the disk also goes up while maintaining the 3 feet hovering distance.

As for part 3, let's take it step by step. Tenser's disk carries stuff, correct? I put a chest on tenser's disk, move 20 feet away, and it will start moving along with the chest towards me, yes? Now, say I put an upper shell casing on top of the disk, just as you might take a CD disk, and put something that looks like one of these ( i.ebayimg.c(o)m/images/g/lvsAAOSwYIxYBf5m/s-l300.jpg ) pieces on top of it. The disk carries it like any other object. Now I bind it to the lower piece, which serves as the "ground" for the disk. Every time the disk carries the upper casing forward, it carries the lower "ground" shell with it as well. And when the disk rises up, it raises the lower casing as well. And since the chainlinks and chair are attached to that shell, they also move in exact synchronization as it.

[Renduaz]

Citations needed

Also, as Stan noted, pulleys, ropes and gravity don't work the way you think... the chair would be sitting on the ground, though tied to the ropes which won't stay taut. At best, you could sit on the chair, pushing yourself on the ground, looking like a fool in the process... and you still wouldn't fly, meaning it was all pointless.

Citations? Read the spell description. And why wouldn't the chainlinks stay taut? That's what wheel mechanism is for. You probably haven't paid attention to the locations, go look at the picture. If it was just the bottom rope, then it would indeed not be taut and just stay on the ground. But it's the diagonal upper rope coming out of the pole which lifts the chair upwards and keeps it in the air. You can try it in your own home. Take 2 strings and a light weight miniature seat-like object, tie one string to a hoop at the bottom, and one to the upper back of the seat. Pull the bottom string in a horizontal line firmly, and the upper one in a diagonal angle upward. Your miniature seat will stay suspended motionlessly. since the upper rope is pulling it away from the ground, and the taut lower rope prevents it from swinging backward.

[Camman1984]

nice contraption, my beholder npc would like to come and have a look ;)

what happens when you recast? you might struggle to get the lower clam to still count as the 'ground' when it is a piece of free floating metal hundreds of feet in the air.

[Renduaz]

nice contraption, my beholder npc would like to come and have a look ;)

what happens when you recast? you might struggle to get the lower clam to still count as the 'ground' when it is a piece of free floating metal hundreds of feet in the air.

Not necessarily since I'm pretty sure even falling surfaces are still ground ( I.E you're on some big cliff edge and it starts falling, you can probably still cast grease on it or any other kind of ground spell, including Tenser's Disk. If it weren't then you might need some kind of brief magical effect to keep it suspended. But I admit I haven't thought of it, since there's nothing in the rules stating that a falling ground stops being the ground.

[JackPhoenix]

Citations? Read the spell description. And why wouldn't the chainlinks stay taut? That's what wheel mechanism is for. You probably haven't paid attention to the locations, go look at the picture. If it was just the bottom rope, then it would indeed not be taut and just stay on the ground. But it's the diagonal upper rope coming out of the pole which lifts the chair upwards and keeps it in the air. You can try it in your own home. Take 2 strings and a light weight miniature seat-like object, tie one string to a hoop at the bottom, and one to the upper back of the seat. Pull the bottom string in a horizontal line firmly, and the upper one in a diagonal angle upward. Your miniature seat will stay suspended motionlessly. since the upper rope is pulling it away from the ground, and the taut lower rope prevents it from swinging backward.

That assume you're applying force to the chair to make the lower rope taut. What would actually happen is this: https://imgur.com/a/mhxpe

Or, if the pull (from what? you have a weight limit, so counterweight is a problematic) on the upper rope is strong enough to lift the chair and its occupant, this: http://imgur.com/JK5XNNe

And Mage Hand is limited to 10 lb, not nearly enough to move chair and its occupant for any maneuvering.

And there's nothing in the spell description about the definition of "ground". So, yes, citation still definitely needed.

[ChampionWiggles]

And there's nothing in the spell description about the definition of "ground". So, yes, citation still definitely needed.

Just answer this question: Can Tenser's Floating Disk be cast on an airship? In a hot-air balloon? If your DM answers yes, it's a similar concept. A moving aerial platform is what the disk considers ground as reference. The only thing that changes is that it provides its own lift.

If your DM answers no, then...your DM kind of made this spell more situational/useless than what it already is.

[Renduaz]

That assume you're applying force to the chair to make the lower rope taut. What would actually happen is this: https://imgur.com/a/mhxpe

Or, if the pull (from what? you have a weight limit, so counterweight is a problematic) on the upper rope is strong enough to lift the chair and its occupant, this: http://imgur.com/JK5XNNe

And Mage Hand is limited to 10 lb, not nearly enough to move chair and its occupant for any maneuvering.

And there's nothing in the spell description about the definition of "ground". So, yes, citation still definitely needed.

Both of your illustrations are impossible since the chainlinks ( Which is what I prefer, moreso than ropes ), but ropes too, are much longer than what you drew. How the hell did a 25-feet rope suddenly turn into a 10-feet rope in your image? magic? No, if the upper rope had enough strength to lif the chair and it's occupant, it would be exactly as it is in my picture. You just magically shortened it's length in yours. You're also completely ignoring the reeling mechanisms which can keep a chainlink taut by locking it in place. Mage hands can only carry up to 10 pounds but I guess that would still apply. Not so problematic however, there are many others ways. Either have someone on the disk, or place another bottom reel on the chair bottom itself, so that you can recoil it back to the shell until it actually looks your like your first image except higher. And besides, I can offer a new design ( i.imgur.c(o)m/iwJKQ1E.png ) that I'm sure you'll be fine with. The solid vertical pole now extends vertically 20+ feet to the chair like a crane, with supporting beams to assist it. At the end of the crane there's a chainlink mechanism which pulls the chair up or down like a well pulley or elevator cable. The bottom chainlink becomes mostly not needed, and is only there mostly to anchor the chair and prevent it from spinning.

As for ground, read the player's handbook on traps, foot tracks, anything you want. Also the spell description says that the disk will float above slopes or stairs as well. How is a wooden stair any different of a "ground" from a wooden slab?

[Renduaz]

Just answer this question: Can Tenser's Floating Disk be cast on an airship? In a hot-air balloon? If your DM answers yes, it's a similar concept. A moving aerial platform is what the disk considers ground as reference. The only thing that changes is that it provides its own lift.

If your DM answers no, then...your DM kind of made this spell more situational/useless than what it already is.

Absolutely, but I'd say that the rules themselves are in favor of allowing it, and that it would actually be very faulty not to. since you can derive the technical permission from the most literal reading, and the absence of restrictions against it. The description says that Tenser's Disk will move up stairs. Any kind of stairs. So let's say I just build a staircase on the soil, and I cast Tenser's Disk on that. Will the disk float 3 feet above the particular stair it's on, with the stair itself being part of the staircase I just built on the soil? Yes it will. The spell description explicitly used that as an example. So it's conclusive that the stair and the staircase can serve as the "ground".

If a giant lifts the staircase, will tenser's disk rise along with it, while still hovering 3 feet above the particular stair? Yes it will, since the spell description says the disk will always 3 feet above it's ground reference, and we also know that "ground" means "the particular spot of ground that the disk is above", since Tenser's disk can climb up stairs, using each stair as the "ground" that it should hover 3 feet above on.

Is a circular wooden or metal slab that I just placed on the ground different from any small staircase which I just placed on the ground, when classifying it as the "ground" for the disk? No it isn't. And if the slab is lifted, will the disk also lift and maintain 3 feet? We established that yes. So the only question that remains is "Will it be a ground if the disk lifts it on it's own", and there's pretty much nothing in the rules which denies that it is possible. So if we said otherwise, we'd have to ask ourselves what happens to the disk as soon as you try making the contraption work? It has to follow me when I'm 20 feet away. It carries the upper shell as an object. The upper shell is attached to the lower one. We've already established, using explicit rules, that the disk will consider the lower casing as it's ground. So if the disk doesn't start moving and thus powering the contraption, what happens to the disk instead? You'd actually have to break most fundamental mechanisms of the spell in order to forbid it.

[nilshai]

Citations? Read the spell description.

I guess he meant citations for the definition of "ground" as a game term.
If you don't have that, ground is what the dm says is. Characters cannot designate something as ground. There is no ability which would allows that. Either something is "ground" by definition, the dm designates it as ground, or it is by common sense. Common sense is obviously out.

[Renduaz]

I guess he meant citations for the definition of "ground" as a game term.
If you don't have that, ground is what the dm says is. Characters cannot designate something as ground. There is no ability which would allows that. Either something is "ground" by definition, the dm designates it as ground, or it is by common sense. Common sense is obviously out.

I'm pretty sure it's somewhere in the handbook, go google "Disciple of Tenser" thread on this forum and read it. The OP cited the handbook to define ground. but it should be taken for granted. There's no such thing as "DM says what ground is" unless you're throwing every known D&D aspect out the window. Is a dungeon floor "ground" for casting grease or the disk to carry loot on? Is a house floor a ground? If your DM says no, I guess he's free to be ridiculous. He's also very close to outright defying Tenser's spell description, since it mentions the disk going up stairs. It would take some true mental gymnastics to decide that stairs are the only type of ground someone can cast Tenser's Disk on alongside the earth's soil. If he rules that it is ground, then it would logically mean any kind of solid material surface is a ground, since they are no different than any artificial house floor or dungeon floor or staircase or pavement. So I take a metallic slab, step on it, it's ground, cast Tenser's Disk on it, and from there proceed to the rest of the spell. Why exactly is common sense obviously out? Which part of the instructions isn't entrenched in common sense? That the ground moves in the air? So tell me, when you're on an airplane, are you unable to spill grease on the ground of the airplane hall? If you are, then you could also cast the spell "Grease" on a flying ground in D&D, thereby also making it ground for the Tenser's Disk spell. It's actually the DM who would have to forego common sense to declare it as anything other than ground.

Here is an actual citation which supports this extremely obvious knowledge:

"Judging by the "Standing in Tight Quarters" rule from page 30 of the DMG, the rules of lying prone, falling, and the descriptions of different form of ground for the purposes of the track skill, any surface that a creature can fight on, fall onto, lie prone on and/or leave tracks on on qualifies as "ground" for that creature." There you go.

[JackPhoenix]

Both of your illustrations are impossible since the chainlinks ( Which is what I prefer, moreso than ropes ), but ropes too, are much longer than what you drew. How the hell did a 25-feet rope suddenly turn into a 10-feet rope in your image? magic? No, if the upper rope had enough strength to lif the chair and it's occupant, it would be exactly as it is in my picture. You just magically shortened it's length in yours. You're also completely ignoring the reeling mechanisms which can keep a chainlink taut by locking it in place. Mage hands can only carry up to 10 pounds but I guess that would still apply. Not so problematic however, there are many others ways. Either have someone on the disk, or place another bottom reel on the chair bottom itself, so that you can recoil it back to the shell until it actually looks your like your first image except higher.

As for ground, read the player's handbook on traps, foot tracks, anything you want. Also the spell description says that the disk will float above slopes or stairs as well. How is a wooden stair any different of a "ground" from a wooden slab?

As there's no scale or measurements included (even in your original image), the whole image is for illustration, not a precise scale model.

It didn't turned into 10' rope or magically shorten in any way, the rope is reeled on the pulley system. If it isn't, what keeps the rope secure? Where does it gets the strength to pull the chair anywhere from? And your picture would work only if there was a force pulling the chair away from the contraption... you can't pull a rope (or chain, whatever) taut if you apply force in only one end... by reeling the rope to the mechanism to apply the force to the chair, you're dragging the chair to the mechanism. It's elementary school physics: http://imgur.com/dLJnznf

You claim that your contraption creates forces F1 and F2 (somehow). But to actually keep the ropes taut, there must also be force F3 equal to the forces F1 and F2 (actually vector sum (is that the name in english?) of those 2 forces, and F3 is actually a vector sum of force FG caused by gravity pulling the chair down and some other force pulling it away from the contraption). If F1 + F2 > F3, the chair will get pulled towards the mechanism, if F3 > F1 + F2, the whole setup gets dragged behind the chair (if possible, rules doesn't say Tenser's Disc may be moved by outside force, if you can't, the force will be applied to the ropes and mechanism until something breaks). Tenser's Disc in the contraption also tries to get closer to the chair until it's in 20' of it, meaning it actually tries to counteract forces F1 and F2.

What could make the whole thing work would be replacing the lower rope/pulley system with solid beam connecting the chair to the disc longer than 20'. The upper rope is not needed in that case. There would, howerer, be no way to stop the thing from moving, and steering would be harder. And the contraption would weight more, which is a problem, you're working with pretty low max weight allowance here.


We've already established, using explicit rules, that the disk will consider the lower casing as it's ground.

This is false. You failed to cite where do you get the idea that any surface counts as "ground". If it does, it leads to absurd interpretations like claiming that your shield counts as a ground (it's big enough to stand on), thus you can't ever fall, because you're touching the ground. Or that vertical walls (or even better, ceilings) counts as ground, thus you can walk on them. Speaking of Tenser's Disc and ground: the spell text also says the disc floats 3 feet off the ground, which mean that the chamber has to be exactly 3 feet high (so the disc is 3' of the lower surface and still touching the upper surface). Other possibilities are that the spell simply fails when it doesn't have enough space to be 3' off the ground, doesn't touch the upper surface, so it doesn't provide any lift or shoots straight up as it tries to get 3' away from the surface that it lifts with it.


Just answer this question: Can Tenser's Floating Disk be cast on an airship? In a hot-air balloon? If your DM answers yes, it's a similar concept. A moving aerial platform is what the disk considers ground as reference. The only thing that changes is that it provides its own lift.

If your DM answers no, then...your DM kind of made this spell more situational/useless than what it already is.

I don't have a DM, so that's a moot. However, I am a GM myself, so I could answer that: Yes, it can be cast on airship or hot-air baloon. However, it does not consider an object it lifts as ground, because that could lead to silly interpretations like players declaring any object their character holds as their ground reference. Or any wall or ceiling (that was actually a thing in 3.5e, some planes... notably Limbo... had something called subjective directional gravity, which meant your character could walk on walls or even "fly" by just declaring the "down" direction being wherever they wanted.)

[N810]

On A slightly related note,
I have been mulling over a devise in my head that would
use immoveable rods and a system of gears and chains and button depressors,
to enable a mobile hovering vehicle. I'm thinking 3 or 4 immoveable rods should do it.

[Squiddish]

On A slightly related note,
I have been mulling over a devise in my head that would
use immoveable rods and a system of gears and chains and button depressors,
to enable a mobile hovering vehicle. I'm thinking 3 or 4 immoveable rods should do it.

Well, if you have a way to prevent the rods from rotating, you could do it with two.

[Phoenix042]

This is fun, but doesn't work, and not for the reasons people keep arguing about.

Yes, the sheet below the disk is "ground." The argument here is clear and well thought out, and I'm sorry to the other posters claiming otherwise, but it simply makes too much sense to dispense with.

The problem is, your cyclical logic as to why the disc holds up the ground is flawed, because cyclical.

If you cast this, say, in midair, the disk would appear, would remain 3ft above the "ground" plate and support the plate above just fine, and the entire system would fall to the ACTUAL ground. When it hit the ground, my intuition is that the disc would still be there, still supporting the upper plate.

Imagine, if you will, a "ground plate" with a 3ft long steel pole jutting up from its center, and on top of that pole, you place another metal plate. You then connect the top plate to the bottom plate via some mechanism, complex or simple. Because the top of the pole can never be more than 3ft from the "ground plate", it will support the top plate, which will support the bottom plate, and you can fly.

And there's the problem. Tensors floating disc hovers relative to the ground, and that ground can also move. And it will. Downward. And so the disc will fall, and never as it falls will the spells rules be broken.

The example of an airship or hot air balloon should make this clear to everyone. If the ship descends while a tensor's floating disc is on deck, so does the disk. If you wrap a rope around the top of the disc and tie it to the ship, does the spell end because the ship weighs more than 500 pounds? Of course not. Only if the rope does. And if you move more than 20ft from it while it's tied down this way, it simply can't move if the rope is trapping it. And if the ship falls from the sky, the disc will remain, not holding up the ship, but still holding up it's rope (3ft above the ship) during the descent.

[Renduaz]

As there's no scale or measurements included (even in your original image), the whole image is for illustration, not a precise scale model.

It didn't turned into 10' rope or magically shorten in any way, the rope is reeled on the pulley system. If it isn't, what keeps the rope secure? Where does it gets the strength to pull the chair anywhere from? And your picture would work only if there was a force pulling the chair away from the contraption... you can't pull a rope (or chain, whatever) taut if you apply force in only one end... by reeling the rope to the mechanism to apply the force to the chair, you're dragging the chair to the mechanism. It's elementary school physics: http://imgur.com/dLJnznf

You claim that your contraption creates forces F1 and F2 (somehow). But to actually keep the ropes taut, there must also be force F3 equal to the forces F1 and F2 (actually vector sum (is that the name in english?) of those 2 forces, and F3 is actually a vector sum of force FG caused by gravity pulling the chair down and some other force pulling it away from the contraption). If F1 + F2 > F3, the chair will get pulled towards the mechanism, if F3 > F1 + F2, the whole setup gets dragged behind the chair (if possible, rules doesn't say Tenser's Disc may be moved by outside force, if you can't, the force will be applied to the ropes and mechanism until something breaks). Tenser's Disc in the contraption also tries to get closer to the chair until it's in 20' of it, meaning it actually tries to counteract forces F1 and F2.

What could make the whole thing work would be replacing the lower rope/pulley system with solid beam connecting the chair to the disc longer than 20'. The upper rope is not needed in that case. There would, howerer, be no way to stop the thing from moving, and steering would be harder. And the contraption would weight more, which is a problem, you're working with pretty low max weight allowance here.



This is false. You failed to cite where do you get the idea that any surface counts as "ground". If it does, it leads to absurd interpretations like claiming that your shield counts as a ground (it's big enough to stand on), thus you can't ever fall, because you're touching the ground. Or that vertical walls (or even better, ceilings) counts as ground, thus you can walk on them. Speaking of Tenser's Disc and ground: the spell text also says the disc floats 3 feet off the ground, which mean that the chamber has to be exactly 3 feet high (so the disc is 3' of the lower surface and still touching the upper surface). Other possibilities are that the spell simply fails when it doesn't have enough space to be 3' off the ground, doesn't touch the upper surface, so it doesn't provide any lift or shoots straight up as it tries to get 3' away from the surface that it lifts with it.



I don't have a DM, so that's a moot. However, I am a GM myself, so I could answer that: Yes, it can be cast on airship or hot-air baloon. However, it does not consider an object it lifts as ground, because that could lead to silly interpretations like players declaring any object their character holds as their ground reference. Or any wall or ceiling (that was actually a thing in 3.5e, some planes... notably Limbo... had something called subjective directional gravity, which meant your character could walk on walls or even "fly" by just declaring the "down" direction being wherever they wanted.)


The thought behind it was that basically the shell is resting on Tenser's disk, while Tenser's disk itself by virtue of magically hovering 3 feet above it 's ground ( In this case the lower casing ), is holding the upper shell case ( which it carries ) via FG ( Force magic ), it's magical property of carrying things up to 500lbs. Now, the pole comes out of that upper shell casing, which is your "F1", exerting extra weight on the disk ( Although not as much as you think, since the shell is extremely thin, and the pole doesn't have to be too hick either, metal works wonder here in providing durability with minimum thickness ). Now as for the chainlinks, it's simple. Imagine there's only the F2 chain, nothing else, and it's ( somehow ) stretched taut with the chair at the end of it. Let's say that happens on the ground. Let's say the device then gets teleported into the air, what happens? The chair, and the chain regardless of how taut it was stretched on the ground, both immediately begin plummeting down, while the bottom chain loosens and starts pulling the chair in an angle towards it, right?

Now imagine that as soon as that starts to happen, a flying giant comes by and grabs the back of the chair firmly. The chair will stay suspended instead of falling, right? So that's basically the "F1" chain force that we seek to recreate. And you're asserting that using the chainlink and pulley with that angle will make the chair swing backwards, since there's isn't force F3 pushing it equally outward. You suggest to replace the lower chainlink with a solid beam to prevent that. But I was under the impression that a chainlink stretched tight enough would act similarly. I'm not sure if "pulley" is the perfect term for it, but there's some kind of modern cable/steel cable mechanism which basically extends the cable so far and then just "locks it" snap shut in place, meaning it can't retract or extend unless engaged, possibly mimicing a solid beam ( Like a steel cable in modern structures ), but a metal chain might not be able to do that.

Anyway, I edited my post to give you an alternative design, which doesn't use a solid beam but still solves all of your issues with it.

As for ground check out my latest post. And your shield can indeed be the ground, and no, that doesn't mean you can't fall, it simply means that your shield is "Ground number 1" and it's falling fast towards "Ground number 2" ( whatever is under you ) and you're about to get hit by the impact. It's basically exactly like a 2-story castle. If your players are in a dungeon with two floors, and they're currently on the second floor, do you not register it as their "ground"? Couldn't they cast grease on it against enemies? Now what happens if it collapses down to the first floor? Wouldn't they take damage from falling because they're on ground? Yes, they still would. Ground 1 falls down to ground 2.

Ceilings and walls probably won't count since "Ground" in the English language on planet earth usually means something which is below. However, if your "ceiling" was something like a flat house roof, you could cast the disk or any other ground spell on it's upper side, but not the lower side. Either way, this is pretty much irrelevant. The lower shell casing is placed somewhere you can walk across it or step on it, and remains below the disk as part of the shell. So arguments about ceilings and walls don't apply.

As for "the chamber has to be exactly 3 feet high" - Actually it doesn't even have to. It could be 4 feet high cylinder with holes at the sides, throw in a slab of metal with similarly placed holes down on tenser's disk from above it, then just bolt the entire thing into place with rods going through the holes, and then weld/seal them if need be.

[Renduaz]

This is fun, but doesn't work, and not for the reasons people keep arguing about.

Yes, the sheet below the disk is "ground." The argument here is clear and well thought out, and I'm sorry to the other posters claiming otherwise, but it simply makes too much sense to dispense with.

The problem is, your cyclical logic as to why the disc holds up the ground is flawed, because cyclical.

If you cast this, say, in midair, the disk would appear, would remain 3ft above the "ground" plate and support the plate above just fine, and the entire system would fall to the ACTUAL ground. When it hit the ground, my intuition is that the disc would still be there, still supporting the upper plate.

Imagine, if you will, a "ground plate" with a 3ft long steel pole jutting up from its center, and on top of that pole, you place another metal plate. You then connect the top plate to the bottom plate via some mechanism, complex or simple. Because the top of the pole can never be more than 3ft from the "ground plate", it will support the top plate, which will support the bottom plate, and you can fly.

And there's the problem. Tensors floating disc hovers relative to the ground, and that ground can also move. And it will. Downward. And so the disc will fall, and never as it falls will the spells rules be broken.

The example of an airship or hot air balloon should make this clear to everyone. If the ship descends while a tensor's floating disc is on deck, so does the disk. If you wrap a rope around the top of the disc and tie it to the ship, does the spell end because the ship weighs more than 500 pounds? Of course not. Only if the rope does. And if you move more than 20ft from it while it's tied down this way, it simply can't move if the rope is trapping it. And if the ship falls from the sky, the disc will remain, not holding up the ship, but still holding up it's rope (3ft above the ship) during the descent.

You're forgetting the character's own magical connection to Tenser's Disk. The disk must always follow the player when the player is 20 feet away. And that means 20 feet in any direction. So if I'm in mid-air, with a chair attached to my contraption more than 20 feet away, at an angle slightly higher than the shell itself, Tenser's Disk can never drop downward. Because Tenser's Disk, whenever you're 20 feet away from it, will get closer to you, not further away from you. So Tenser's disk will have to fly at an upper angle like an actual airplane on takeoff in order to follow my direction. It won't drop because that would make it further away from me. It would perpetually fly forward with an upward angle to try and reach me.

[Crusher]

This is absolute genius.

I'd never allow it in a game I was DMing (I wouldn't argue rules, I'd just say "no" and move on), but its absolute genius. I'd shoot it down (pun intended), but I'd find a way to reward you for clever thinking. Inspiration or something.

[N810]

Well, if you have a way to prevent the rods from rotating, you could do it with two.
looks like I need 6 if I am going to be able to turn...



https://scontent-sjc2-1.xx.fbcdn.net/v/t1.0-9/fr/cp0/e15/q65/17757446_10155208072791096_5763463331835059822_n.j pg?efg=eyJpIjoiYiJ9&oh=30720155fe061db141c9e0aa3cbd1add&oe=596732A8

The big pyramid is a suspended platform.

The basic idea is a automatic immoveable rod ladder.
so it's going to take a little muscle power.
the red circles are rods that are off, the blue circles are on,
the squares turn the rods on and off.
the 2 yellow objects are fixed rods on ball bearings,
to change directions. you have to stop and activate one of those
and then hit the big button to turn of the tracked rods,
the manually swivel the devise, turn the rods back on the pivot rod off again
and them go in your new direction.

[Renduaz]

You are a god among men.


This is absolute genius.

I'd never allow it in a game I was DMing (I wouldn't argue rules, I'd just say "no" and move on), but its absolute genius. I'd shoot it down (pun intended), but I'd find a way to reward you for clever thinking. Inspiration or something.

Thank you both, so far I think the only viable opposition to the Tenser's Drive ( The flight engine itself ) is the disk not being able to carry it's own ground, however that's more of a house rule, not a hard rule, since there's nothing saying the disk can't do so, just like the force of hot air in a hot air balloon is carrying the basket with it by pushing against the balloon itself. And all the other arguments about the contraption design are not very important ( And have been mostly fixed ), since there are many designs possible when one allows for the Tenser's Drive. So I agree with you that it should be left up to the DM, knowing that Tenser's Skystrider can very likely be built on a hard rule basis.

[Cybren]

Thank you both, so far I think the only viable opposition to the Tenser's Drive ( The flight engine itself ) is the disk not being able to carry it's own ground, however that's more of a house rule, not a hard rule, since there's nothing saying the disk can't do so, just like the force of hot air in a hot air balloon is carrying the basket with it by pushing against the balloon itself. And all the other arguments about the contraption design are not very important ( And have been mostly fixed ), since there are many designs possible when one allows for the Tenser's Drive. So I agree with you that it should be left up to the DM, knowing that Tenser's Skystrider can very likely be built on a hard rule basis.

Ah, the Air Bud Defense

[Tanarii]

8/10, Great Read! Not the least of which because it's full of logical holes and misinterpretations of RAW, which adds perfect topping to the comedy effect that was (hopefully) being aimed for.

[Renduaz]

8/10, Great Read! Not the least of which because it's full of logical holes and misinterpretations of RAW, which adds perfect topping to the comedy effect that was (hopefully) being aimed for.

You should probably point out those logical holes and misinterpretations.

[Tanarii]

You should probably point out those logical holes and misinterpretations.
You wrote it. Surely you already knew them when you chose to use them to such comedic effect?

[Renduaz]

You wrote it. Surely you already knew them when you chose to use them to such comedic effect?

Oh I see, you're *that guy*. There have been others who expressed their criticism, and we discussed it. Where it be ground references, piloting, renewing the spell. But you're just here to be snide. You will never comment about what those logical holes and misrepresentations of RAW actually are, will you? You'll just reply snidely once again. And no doubt you also won't stop until you get the final word in passive-aggressiveness. Am I predicting this correctly? Or are you going to specify all of those unbelievable flaws which are apparently known only to you?

[ChampionWiggles]

I really like this idea and the logic behind Tenser's Drive makes sense to me. The chain apparatus doesn't quite make sense to me, but I wasn't the best at physics/statics/dynamics, so that doesn't necessarily mean it's wrong. Using some poles would make more sense to me, personally. If I were DMing a campaign and someone tried this, I'd allow it. Creativity should be rewarded, not hindered. And saying "I'm not allowing this, because reasons" is bad DMing in my eyes. Instead, if the players started abusing this, as a DM, that's when you create conditions that make the device not as easy to use.

"So you pilot your magic plane...and it's REALLY windy. Make me a DEX saving throw (or vehicle proficiency check, IDK) to make sure you don't get blown out of the sky"
Or rumor starts spreading across the land about the adventurers using a magic plane and baddies prepare accordingly for it. Something like that.

I'd probably also add the caveat of "Well, is your character smart enough to think of this idea and implement it?" and have them pass an initial INT check, that the Wizard would most likely be the one to pass.

[Renduaz]

I really like this idea and the logic behind Tenser's Drive makes sense to me. The chain apparatus doesn't quite make sense to me, but I wasn't the best at physics/statics/dynamics, so that doesn't necessarily mean it's wrong. Using some poles would make more sense to me, personally. If I were DMing a campaign and someone tried this, I'd allow it. Creativity should be rewarded, not hindered. And saying "I'm not allowing this, because reasons" is bad DMing in my eyes. Instead, if the players started abusing this, as a DM, that's when you create conditions that make the device not as easy to use.

"So you pilot your magic plane...and it's REALLY windy. Make me a DEX saving throw (or vehicle proficiency check, IDK) to make sure you don't get blown out of the sky"
Or rumor starts spreading across the land about the adventurers using a magic plane and baddies prepare accordingly for it. Something like that.

Yes, the chain mechanism might not be optimized enough, as I've spoken about with another poster here. I offered a new design ( i.imgur.c(o)m/iwJKQ1E.png ) which ought to solve any existing physical violations. Instead of the two chains, it will simply be the pole, a beam coming out of like a crane, two support beams to keep it firm, and the pulley being placed at the end, with a chain or rope dangling down so the player can lift or lower himself, much like a bucket in a wellspring. Two other chains should probably attached at the sides, linked to the sides of the shell itself, for maneuvering left and right.

I wouldn't mind if it was being hindered if the rules forbade it, but I took great care to abide by almost everything I could think of. And where I didn't, that's why I said in the OP that I'm interesting in improvements or better alternatives if anyone can think of them.

[Haldir]

Nah bro, you made a very liberal rules interpretation with the disk. This would never fly with a DM worth his/her salt.

[ChampionWiggles]

Nah bro, you made a very liberal rules interpretation with the disk. This would never fly with a DM worth his/her salt.

Why? If you cast or place the disc on some sort of box or wood pallet and then lift that up off the ground a couple of feet, would it not rise up with it? Can the disk not ride on elevator type devices?

[Renduaz]

Nah bro, you made a very liberal rules interpretation with the disk. This would never fly with a DM worth his/her salt.

It's the DM's choice. But while it may not be straight up RAI, I wouldn't say it's "very liberal". Each step of the way has a legal precedent for it. If a DM accepts that a house floor or a balcony or a bridge or even a raised patio is a ground, and since Tenser's spell description straight up says that Tenser's Disk will climb up stairs ( Meaning, any kind of stair, wooden, metallic, whatever is a ground to it ), then a circular metallic or wooden surface will also be a ground. All of these are no different. And if it's a ground, Tenser's disk can be cast on it. And since I can place anything on the disk according to the spell description, I can place an upper surface on the disk and attach it to the lower.

Then we get to the "will it fly part", which is also backed by the spell RAW itself. Does Tenser's Disk always hover 3 feet above the particular area of ground that it's above? Yes, it does. The spell description itself says that it will climb up on slopes, uneven terrain and stairs ( artificial surface ), always maintaining an elevation of 3 feet above whatever is beneath it at a given moment. So if you lift the lower surface the disk floats above, it will rise accordingly, with the upper shell on top of it. And that basically wraps up the "Tenser's Drive" part of the device. It's all very strict.

Think of the disk, which is a plane of force, as densely packed air. Can the hot air in an hot air balloon push a basket up constantly by lifting the balloon on top of it, with the balloon attached to the basket? Yes, that's how it works in real life. And Tenser's Disk, possessing the magical property of always floating 3 feet above something, is much like a disk of hot air in that regard. If that's how you want to conceive of it.

[Steampunkette]

Ground is ground. Ground is not dirt, nor metal, nor rock, nor wood. Ground is ground.

Even if I were to entertain your little thought experiment, the instant the lower piece is no longer connected to the ground it is no longer ground and the disk continues floating at the same height. If you take a tenser's disk over a hill it follows the curve of the hill. If you walk it off a bridge it drops to ground level relative to itself.

Your interpretation is funny, but takes a massive leap of logic and pretends it's not even there.

It would never work.

[Renduaz]

Why? If you cast or place the disc on some sort of box or wood pallet and then lift that up off the ground a couple of feet, would it not rise up with it? Can the disk not ride on elevator type devices?

Or if you're standing in some kind of treehouse with a tenser's disk to place your loot on, 3 feet above the wooden floor, and the tree it was built on turns out to be a treant, and slowly raises along with the tree house, does my spell suddenly fizzle out for no reason, or the disk crash down? Or does the disk simply adjust itself to rise along with the ground so that it hovers 3 feet above?

She spell description supports the latter, not the former. So indeed, it's an error to call it a very liberal reading.

[Beelzebubba]

I'd laugh, throw you a few inspiration points, let it work once or twice, and then stop it while opening up a quest to allow you to craft a spell that gives you what you want, at the appropriate higher spell slot.

I'm thinking some Djinn or legalistic little magic spirit popping in and saying, 'Mystara is very annoyed at you! Stop playing games!' and canceling the effect when you have a bunch of stuff stacked on it... but winks as it leaves behind a little slip of paper with a recipe...

"Three feathers of a Roc at sunrise, body of a flounder with blue eyes..."

...and the characters have a new adventure.

[Renduaz]

Ground is ground. Ground is not dirt, nor metal, nor rock, nor wood. Ground is ground.

Even if I were to entertain your little thought experiment, the instant the lower piece is no longer connected to the ground it is no longer ground and the disk continues floating at the same height. If you take a tenser's disk over a hill it follows the curve of the hill. If you walk it off a bridge it drops to ground level relative to itself.

Your interpretation is funny, but takes a massive leap of logic and pretends it's not even there.

It would never work.

"Ground is not dirt, nor metal, nor rock, nor wood. Ground is ground." - You've just ruled every single dungeon or house floor or city pavement or tower in the realms not to qualify as having a ground, since all of their "ground" are artificially placed slabs of rock, wood, metal, ceramic and so forth. That means your players won't be able to cast any kind of ground spell like Grease in any dungeon or house or city street.

"the instant the lower piece is no longer connected to the ground it is no longer ground" - That's basically the airship/floating city argument which has been addressed here before. If your characters are walking on an airship, or if they are in the City of Brass ( A floating Efreeti city in the planes ), do you not let them cast anything on the ground, because the "ground" of an airship or floating city isn't connected to the earth's soil?

[druid91]

Why? If you cast or place the disc on some sort of box or wood pallet and then lift that up off the ground a couple of feet, would it not rise up with it? Can the disk not ride on elevator type devices?

This actually opens up possibilities of it's own. If the disc cannot rise with solid ground that is made 'unsolid' then placing a tensers floating disk on a collapsible arch, then collapsing it above the bad guy.

The disc immediately plumets downward. If your bad guy is higher than three feet tall, he gets nailed into the ground by a disc of force and is subsequently exactly three feet tall.

Not quite as amazing as an airplane, but still shenanigan-laden.

[ChampionWiggles]

This actually opens up possibilities of it's own. If the disc cannot rise with solid ground that is made 'unsolid' then placing a tensers floating disk on a collapsible arch, then collapsing it above the bad guy.

The disc immediately plumets downward. If your bad guy is higher than three feet tall, he gets nailed into the ground by a disc of force and is subsequently exactly three feet tall.

Not quite as amazing as an airplane, but still shenanigan-laden.

As long as said arch isn't over 10 feet tall

[ChampionWiggles]

Ground is ground. Ground is not dirt, nor metal, nor rock, nor wood. Ground is ground.

Even if I were to entertain your little thought experiment, the instant the lower piece is no longer connected to the ground it is no longer ground and the disk continues floating at the same height. If you take a tenser's disk over a hill it follows the curve of the hill. If you walk it off a bridge it drops to ground level relative to itself.

Your interpretation is funny, but takes a massive leap of logic and pretends it's not even there.

It would never work.

Ah circular reasoning. Arbitrary definition is arbitrary.

[Renduaz]

This actually opens up possibilities of it's own. If the disc cannot rise with solid ground that is made 'unsolid' then placing a tensers floating disk on a collapsible arch, then collapsing it above the bad guy.

The disc immediately plumets downward. If your bad guy is higher than three feet tall, he gets nailed into the ground by a disc of force and is subsequently exactly three feet tall.

Not quite as amazing as an airplane, but still shenanigan-laden.

That would actually work regardless. Whether or not Tenser's disk can rise up with solid ground which is "made unsolid" ( suspended in the air? ) beneath it ( And it can ), a collapsible arch won't be unsolid ground nor rising ground, it will simply no longer be beneath Tenser's Disk, and therefore the disk will probably revert to whatever is underneath it, which is going to be the ground below the arch.

[Renduaz]

As long as said arch isn't over 10 feet tall

Yes, that too. Although the outcome here is peculiarly uncertain. According to the spell description, the disk can't change an elevation of more than 10 feet from the ground it currently hovers above, but the description doesn't say the spell will fade out or something if it does, it simply says that the disk will remain stuck in place and won't cross the elevation.

So if we had a two-floor house, with 10 feet height between them, and we cast Tenser's disk on the second floor, and the second floor collapses down to the first - Does Tenser's Disk remain stuck in the air, 10+ feet above the first floor ( As we know, it can't change an elevation of more than 10 feet from it's ground reference ), or does it descend down to the next available ground reference ( First floor ), seeing as how it's just lost the initial ground?

[ChampionWiggles]

This actually opens up possibilities of it's own. If the disc cannot rise with solid ground that is made 'unsolid' then placing a tensers floating disk on a collapsible arch, then collapsing it above the bad guy.

The disc immediately plumets downward. If your bad guy is higher than three feet tall, he gets nailed into the ground by a disc of force and is subsequently exactly three feet tall.

Not quite as amazing as an airplane, but still shenanigan-laden.

Actually, now that I think about it, this probably wouldn't work. It's based on interpretation, but the last paragraph of the spell says that the disc CAN be obstructed and moved, so I doubt it doesn't take a whole lot of force to move it. Doubtful it has enough force to "crush" your enemies, even with this interpretation. That's not to say you can do the same trick with say...a 400 lbs boulder and end the spell as the arch collapses or something.

[Sabeta]

Yeah, I understand the mechanisms in place here, but it relies on gratuitous use of rules that don't exist (eg. Air Bud Clause) to make it work. At the very least, this is clearly not RAI.

Even if it did
A) It would be incredibly slow.
B) It would be prone to stiff winds, which could potentially knock it over change its direction and other make for a nearly impossible or at least joyless ride.
C) Would be a huge enemy target because WHAT IS THAT THING
D) Would probably be more than capable of breaking, possibly from that stiff breeze earlier.

[ChampionWiggles]

Yes, that too. Although the outcome here is peculiarly uncertain. According to the spell description, the disk can't change an elevation of more than 10 feet from the ground it currently hovers above, but the description doesn't say the spell will fade out or something if it does, it simply says that the disk will remain stuck in place and won't cross the elevation.

So if we had a two-floor house, with 10 feet height between them, and we cast Tenser's disk on the second floor, and the second floor collapses down to the first - Does Tenser's Disk remain stuck in the air, 10+ feet above the first floor ( As we know, it can't change an elevation of more than 10 feet from it's ground reference ), or does it descend down to the next available ground reference ( First floor ), seeing as how it's just lost the initial ground?

This thread should get renamed to "Over Complicating What Was Designed to be a Simple Spell" XD

[Steampunkette]

"Ground is not dirt, nor metal, nor rock, nor wood. Ground is ground." - You've just ruled every single dungeon or house floor or city pavement or tower in the realms not to qualify as having a ground, since all of their "ground" are artificially placed slabs of rock, wood, metal, ceramic and so forth. That means your players won't be able to cast any kind of ground spell like Grease in any dungeon or house or city street.

"the instant the lower piece is no longer connected to the ground it is no longer ground" - That's basically the airship/floating city argument which has been addressed here before. If your characters are walking on an airship, or if they are in the City of Brass ( A floating Efreeti city in the planes ), do you not let them cast anything on the ground, because the "ground" of an airship or floating city isn't connected to the earth's soil?

.... yeah. You totally missed the entire point of the post and went for a semantic attack. Not cute.

Sure Tenser's would work on a boat or an airship or the surface of water, itself. Those things are all "Ground". My statement was explicitly that ground is not a particular substance but a relative position (Hence the disk falling off a bridge or following a hill, showing that ground is relative).

As to arbitrary definitions: ALL definitions are arbitrary because language is nothing more than a social construct, but let's not get into Camus's bovine scatology. Ground is "The solid surface of the earth". We can expound that to allow for things connected to the ground, or on the ground. But a flying chunk of thin metal is not ground.

When you get into an elevator on the Ground Floor of a building are you 30ft off the ground? What if there's a skywalk between two buildings, is the 3rd floor where they connect now the ground floor? No. It's the third floor. And the ground floor is still the ground floor.

How about if it's the 3rd floor on one building and the ground floor of the other because of elevation differences in foundations? Now it's the third floor from some unspecified perspective and ground floor from the other.

A flying disk is not "Ground". A flying disk is a flying disk. Encapsulating the Tenser's disk in metal does not mystically bestow upon that egg shaped vehicle the determination of "Ground" any more than flying through the air makes the Air around the plane "Ground".

Ground is Ground. And a floating disk hovering 3 feet under tenser's disk is not ground.

Your arguments take off on flights of fancy. Mine are the grounded ones. Or maybe I'm just not as shocking and scintillating as you because I'm more grounded. But I think these puns which demonstrate that ground means many things but not what you're looking for are grounds for me to be grounded.

/Thread

[ChampionWiggles]

Yeah, I understand the mechanisms in place here, but it relies on gratuitous use of rules that don't exist (eg. Air Bud Clause) to make it work. At the very least, this is clearly not RAI.

Even if it did
A) It would be incredibly slow.
B) It would be prone to stiff winds, which could potentially knock it over change its direction and other make for a nearly impossible or at least joyless ride.
C) Would be a huge enemy target because WHAT IS THAT THING
D) Would probably be more than capable of breaking, possibly from that stiff breeze earlier.

A) Not necessarily. It's not defined how fast the disc follows the user. It's assumed to be slow (or at the same rate the user moves, maybe). But the DM could easily say this thing goes at Mach 3 to make it impossible to control and an incentive to not use it.
B) I point this out earlier as something I'd do as a DM if the group started to abuse this.
C) Up to the DM. A lot of people (or bandits) might just be awe struck trying to figure out what it was at first. But the pilot could easily fly high enough out of the reach of ranged weapons from the ground, if this thing is allowed.
D) Would be a thing to have the group consider as DM, too (If you allow this).

[Renduaz]

Actually, now that I think about it, this probably wouldn't work. It's based on interpretation, but the last paragraph of the spell says that the disc CAN be obstructed and moved, so I doubt it doesn't take a whole lot of force to move it. Doubtful it has enough force to "crush" your enemies, even with this interpretation. That's not to say you can do the same trick with say...a 400 lbs boulder and end the spell as the arch collapses or something.

I've seen the passage not following you when obstructed, but I'm pretty sure it doesn't say that Tenser's Disk can be move ( By anything other than the player being more than 20 feet away from it ). Are you reading the 5E description?


Yeah, I understand the mechanisms in place here, but it relies on gratuitous use of rules that don't exist (eg. Air Bud Clause) to make it work. At the very least, this is clearly not RAI.

Even if it did
A) It would be incredibly slow.
B) It would be prone to stiff winds, which could potentially knock it over change its direction and other make for a nearly impossible or at least joyless ride.
C) Would be a huge enemy target because WHAT IS THAT THING
D) Would probably be more than capable of breaking, possibly from that stiff breeze earlier.

I agree it is not pure RAI, but I wouldn't say it's pure Air Bud Clause either, since I'm mostly relying on inferences from actions which are RAI ( I.E Tenser's ability to climb up stairs, which gives us info on it's positioning and how it works with ground references, and the size of ground that it changes elevation for ). The Air Bud Clause would probably be not the floating ground aspect ( Because D&D has many floating cities, platforms, etc.. at times and we both know that you can cast Grease or any kind of ground spell while adventuring on those if you wanted to ), but more the "carrying it's own ground" idea specifically.

However that has a precedent in real-world physics, which is the hot air balloon. Tenser's disk ( A floating plane of force ) is no different than the force of compressed hot air, the upper shell in this scenario is no different than the balloon, and the lower shell is no different than the basket. The sole difference is that Tenser's Disk doesn't naturally keep trying to rise upward. But my design accommodates that by angling upward 20 feet away from the disk ( Thus making it rise forward and up in an attempt to follow me. Which is also RAI, since Tenser's explicitly climbs at an angle up slopes and stairs to follow a player ). So I'd say it's a decent RAW presentation, albeit not RAI.

A) I don't know how fast the disk tries to follow when it's away ( Previous editions said it matches player's speed I think ), but I agree, a DM could pick any speed he wanted to in this edition
B) The disk itself can't be knocked over, and therefore not the shell which encases it, since the disk only moves according to the player. It's magically unaffected. But the real problem would be the chair. In that case, I think that chainlink attachments might at least be strong enough to let you keep a general direction, if not accurately.
C) If you're flying at very high altitudes, like 5km or something, it might actually seem less than a dot from the ground.
D) That's why I recommended using a metallic casing for the shell and chainlinks for pulling yourself in different directions. Probably impossible to break by wind.

[Renduaz]

This thread should get renamed to "Over Complicating What Was Designed to be a Simple Spell" XD

That's all the fun. It's actually what engineers and physicians are tasked with doing in real life, exploiting minor quirks in the laws of physics to draw immense usefulness out of them.


.... yeah. You totally missed the entire point of the post and went for a semantic attack. Not cute.

Sure Tenser's would work on a boat or an airship or the surface of water, itself. Those things are all "Ground". My statement was explicitly that ground is not a particular substance but a relative position (Hence the disk falling off a bridge or following a hill, showing that ground is relative).

As to arbitrary definitions: ALL definitions are arbitrary because language is nothing more than a social construct, but let's not get into Camus's bovine scatology. Ground is "The solid surface of the earth". We can expound that to allow for things connected to the ground, or on the ground. But a flying chunk of thin metal is not ground.

When you get into an elevator on the Ground Floor of a building are you 30ft off the ground? What if there's a skywalk between two buildings, is the 3rd floor where they connect now the ground floor? No. It's the third floor. And the ground floor is still the ground floor.

How about if it's the 3rd floor on one building and the ground floor of the other because of elevation differences in foundations? Now it's the third floor from some unspecified perspective and ground floor from the other.

A flying disk is not "Ground". A flying disk is a flying disk. Encapsulating the Tenser's disk in metal does not mystically bestow upon that egg shaped vehicle the determination of "Ground" any more than flying through the air makes the Air around the plane "Ground".

Ground is Ground. And a floating disk hovering 3 feet under tenser's disk is not ground.

Your arguments take off on flights of fancy. Mine are the grounded ones. Or maybe I'm just not as shocking and scintillating as you because I'm more grounded. But I think these puns which demonstrate that ground means many things but not what you're looking for are grounds for me to be grounded.

/Thread

You've contradicted yourself. You say Tenser's Disk will work on an airship, then you proceed to say that you can "expound that to allow for things connected to the ground, or on the ground. But a flying chunk of thin metal is not ground.". An airship is a chunk of material which is neither connected to the ground, nor is it on the ground. A real-life airplane is a flying chunk of metal ( Albeit an aerodynamic one ).

Your "ground floor" analogy....what is often called "Ground floor" in the context of architecture has nothing to do with the definition of "Ground" in other circumstances. Yes, the ground of the 3rd floor is ground, and if you're in an elevator which goes up 30feet, then you're 30feet above the bottom of the elevator, and 1feet above the elevator ground. But anyway, you contradicted yourself in that post. You said you'd constitute an airship as "ground" and then said that something which isn't connected or on the ground isn't ground. I'll also add that the surface of water constituting a ground ( Which seems to be fine by you ) is much more of an allowance than a metallic surface. Since we know in D&D you can cast ground spells both on soild and floating grounds ( Such as floating Netherese or Djinn cities ), but we don't know if you can cast them on water. There are a couple of blatant contradictions and inconsistencies in your post.

[Steampunkette]

That's all the fun. It's actually what engineers and physicians are tasked with doing in real life, exploiting minor quirks in the laws of physics to draw immense usefulness out of them.



You've contradicted yourself. You say Tenser's Disk will work on an airship, then you proceed to say that you can "expound that to allow for things connected to the ground, or on the ground. But a flying chunk of thin metal is not ground.". An airship is a chunk of material which is neither connected to the ground, nor is it on the ground. A real-life airplane is a flying chunk of metal ( Albeit an aerodynamic one ).

Your "ground floor" analogy....what is often called "Ground floor" in the context of architecture has nothing to do with the definition of "Ground" in other circumstances. Yes, the ground of the 3rd floor is ground, and if you're in an elevator which goes up 30feet, then you're 30feet above the bottom of the elevator, and 1feet above the elevator ground. But anyway, you contradicted yourself in that post. You said you'd constitute an airship as "ground" and then said that something which isn't connected or on the ground isn't ground.

Oh noes! I contradicted myself! My entire argument has crumbled to pieces!

Nah, man. Just that one line is wrong by that definition. Though wrong or not I'd still allow it because the spell is based on a game and in that game everything is relative, particularly "Ground Level" as relates to airborne combat. Elevation 0, to quote 4e rules.

But a disk designed to encapsulate a TFD? That's not ground, dude. That's a vehicle. At least the airship (Or airplane, or boat, or whatever) has a support relative to the surface that could be considered "Ground Level" for rules as relates to the game world... but the capsule?

It's just a capsule. It's not ground.

Honestly I'm shocked you didn't hop onto "Water isn't ground!" as the "Your argument is invalid because this one example picked out of the whole thing doesn't fit the criteria".

[Renduaz]

Oh noes! I contradicted myself! My entire argument has crumbled to pieces!

Nah, man. Just that one line is wrong by that definition. Though wrong or not I'd still allow it because the spell is based on a game and in that game everything is relative, particularly "Ground Level" as relates to airborne combat. Elevation 0, to quote 4e rules.

But a disk designed to encapsulate a TFD? That's not ground, dude. That's a vehicle. At least the airship (Or airplane, or boat, or whatever) has a support relative to the surface that could be considered "Ground Level" for rules as relates to the game world... but the capsule?

It's just a capsule. It's not ground.

Honestly I'm shocked you didn't hop onto "Water isn't ground!" as the "Your argument is invalid because this one example picked out of the whole thing doesn't fit the criteria".

Yes, it's a vehicle whose "ground" is the lower shell casing, much like a giant slab of metal is the "ground" of a Zeppelin which people step on, dance on, put stuff on, you know. What "support" does an airship have relative to the surface which makes it ground, but not the shell? Aerodynamics? Great. And what support relative to the ground does the City of Brass or a Netherese floating city have that my design doesn't? My design relies on the innate magic of the disk to levitate itself, much like any other kind of floating surface in D&D.

Listen, I have no problem if you want to forbid the design in a house rule. But you're simply wrong in your arguments.

[Steampunkette]

Yes, it's a vehicle whose "ground" is the lower shell casing, much like a giant slab of metal is the "ground" of a Zeppelin which people step on, dance on, put stuff on, you know. What "support" does an airship have relative to the surface which makes it ground, but not the shell? Aerodynamics? Great. And what support relative to the ground does the City of Brass or a Netherese floating city have that my design doesn't? My design relies on the innate magic of the disk to levitate itself, much like any other kind of floating surface in D&D.

Listen, I have no problem if you want to forbid the design in a house rule. But you're simply wrong in your arguments.

The city of brass can support TFD because it is supported by magic relative to the ground. The Airship is supported by heated gasses relative to the ground. The Airplane is lifted by air currents relative to the ground. In all those examples the TFD is sitting on something that by it's nature is already supported by magic or physics.

The shell you're referring to doesn't provide anything. It's a shell. It doesn't give the TFD anything to push off of except itself. Like magically grabbing one's own bootstraps to lift yourself into the air. It doesn't have lift from fast moving air, gass, or magic. It's just a piece of metal, sitting on the ground.

TFD doesn't do that. There's nothing in the rules that says it can do that. You're going Air Bud, to quote previous posters. You're going for a loophole and hoping that by ripping it open wide enough your theory will fit.

[Steampunkette]

Anyone remember in 3e the idea of having a Gnome mage cast the spell with a tarp full of dirt tied to the underside of the disk to provide "Ground" for it to float?

Yeah. Same goofy "Let's bend the rules as hard as we can" interpretation.

[Sabeta]

I agree with Steampukette. Tensors works on bridges and buildings because those things are connected to the ground. It could work on Airships and Airplanes because those things have achieved lift. Using a nonflying series of plates and pulleys doesn't work. The rules also don't say anything along the lines of being able to bring the ground with you, or if the spell simply locks onto a geographic elevation, or if it's limited to a specific "layer" of the weave, or anything at all. Trying to game something from that lack of knowledge is Air Bud. No sane DM should allow such a thing, and if they did then just see my previous post.

Neither on a mechanical nor conceptual level does this seem to work.

[Aerogellin]

Just popping in to ask: Why is everybody taking this so seriously?

Renduaz made a funny invention that is technically correct by RAW (Albiet completely RAW over RAI, which contributes to the hilarity as I believe Tanarii tried to point out earlier (Though he could have been a little more clear)). If you're trying to argue that he's wrong based on logic or how you'd houserule it, you're not making your argument anywhere near to the same level that he is. Given how clever of a play this is, I think we can all assume (And Renduaz, confirm this for me if you'd like) that the creator knows how ridiculous this is.

All in all this is a great look at how the rules as written can do some funky things even in 5E, and exploits a fun loophole and gives us a hilarious and fun build. I'd never advocate actually bringing this into the game, but it serves as a great example and teaches some interesting and fun rules.

I laughed, I learned, I loved. I hope you all do too.

~Aerogellin

[Renduaz]

The city of brass can support TFD because it is supported by magic relative to the ground. The Airship is supported by heated gasses relative to the ground. The Airplane is lifted by air currents relative to the ground. In all those examples the TFD is sitting on something that by it's nature is already supported by magic or physics.

The shell you're referring to doesn't provide anything. It's a shell. It doesn't give the TFD anything to push off of except itself. Like magically grabbing one's own bootstraps to lift yourself into the air. It doesn't have lift from fast moving air, gass, or magic. It's just a piece of metal, sitting on the ground.

TFD doesn't do that. There's nothing in the rules that says it can do that. You're going Air Bud, to quote previous posters. You're going for a loophole and hoping that by ripping it open wide enough your theory will fit.

What exactly is "magic relative to the ground" and where do you derive your idea that the City of Brass was created by it. And what do you mean by heated gasses/air currents "relative to the ground"? It's just a pocket of hot air in the hot air balloon. And as for magic, that applies in my example too. The TFD is supported by it's own magical attributes. ( By the way, you don't actually know what levitates the City of Brass or how it works ). And I already suggested that you should understand the TFD and the shell like a hydrogen or helium airship. Those gasses provide lift because they're lighter than air, so imagine Tenser's Disk ( Which is just a plane of force ) as the equivalent of that, but floating 3 feet in the air instead of constantly rising. The balloons of the ship will be the "upper shell", and their decks will be the "lower shell".

It's not like pulling yourself by the bootstraps. Because my bootstraps don't always follow me in any direction magically whenever I'm 20 feet away from them. Tenser's disk does magically, hence why I can propel it upward.

[druid91]

The city of brass can support TFD because it is supported by magic relative to the ground. The Airship is supported by heated gasses relative to the ground. The Airplane is lifted by air currents relative to the ground. In all those examples the TFD is sitting on something that by it's nature is already supported by magic or physics.

The shell you're referring to doesn't provide anything. It's a shell. It doesn't give the TFD anything to push off of except itself. Like magically grabbing one's own bootstraps to lift yourself into the air. It doesn't have lift from fast moving air, gass, or magic. It's just a piece of metal, sitting on the ground.

TFD doesn't do that. There's nothing in the rules that says it can do that. You're going Air Bud, to quote previous posters. You're going for a loophole and hoping that by ripping it open wide enough your theory will fit.

Err, It's a FLOATING disc. It already does lift itself up by the bootstraps. It uses the ground as a target. In this case, it's less like pulling yourself up by your bootstraps, and more like dropping a cinderblock on the gas pedal to get a car to do something it wouldn't normally do.

TFD doesn't push off of ANYTHING. It just isn't programmed to do that.

[Sabeta]

snip

I don't see any RAW that says the ground can be brought along with the disk to create an airship.

[Renduaz]

I agree with Steampukette. Tensors works on bridges and buildings because those things are connected to the ground. It could work on Airships and Airplanes because those things have achieved lift. Using a nonflying series of plates and pulleys doesn't work. The rules also don't say anything along the lines of being able to bring the ground with you, or if the spell simply locks onto a geographic elevation, or if it's limited to a specific "layer" of the weave, or anything at all. Trying to game something from that lack of knowledge is Air Bud. No sane DM should allow such a thing, and if they did then just see my previous post.

Neither on a mechanical nor conceptual level does this seem to work.

How is working on airship relevant to whether or not they achieved lift? And you're right about the rules not saying along the lines of something carrying it's own ground. Except they say nothing about not being able to either. As I posted before, if I'm in a tree house built on a tree, fighting enemies inside it, can I cast grease on the treehouse foor? If yes, then you ruled it to be "ground". Now, if the tree turns out to be a treant, does that mean the house floor is no longer ground suddenly? What if it's a flying treant of some sort?

But you're mistaken about locking onto a geographic elevation. It explicitly gives us the information on that, which I posted about like a 1000 times already, and apparently will keep having to post about - the spell description says that Tenser's Disk will climb up slopes and STAIRS. That means Tenser's Disk locks onto whatever surface is beneath it at any given moment and adjusts it's levitation accordingly. Otherwise it would get stuck in stairs.

You can call "Air Bud" on carrying the disk's own ground if you want.

[Renduaz]

I don't see any RAW that says the ground can be brought along with the disk to create an airship.

But you see rules ( In the handbook's section on traps, tracking, etc.. ) which state a wooden or metallic surface would qualify as ground, that tenser's disk floats 3 feet above ground, that tenser's disk will move in any direction to follow the player, if the player is 20 feet away from it, which all combined, would implicitly allow for the device. You can call it "Air Bud", but honestly, I think that "Air Bud" thing is silly.

The rules don't say whether you can cast a minor illusion only of something you've seen before or of something you can imagine too. So what, now if I want to cast a minor illusion of a box with a certain pattern that I imagined but haven't seen before, then that's "Air Bud logic", because it's not spelled out in the rules?

[druid91]

I don't see any RAW that says the ground can be brought along with the disk to create an airship.

Ground has two relevant definitions here.

One is "The Solid Surface of the Earth" which is ridiculously narrow. The logical breaks in this interpretation have already been covered.

and two is "A solid surface that can be walked upon."

Can you not walk upon a metal disc? Yes. Yes you can. Meaning it counts as ground. Can you not still walk upon it even if it's being moved?

Meaning as long as you don't try to go vertical, you're good.

It's not like this is even broken. You move 10 feet a round at the most, trade your wizard's spellcasting in exchange for him operating this contraption, A shatter spell will wreck your day, and you can barely carry the party and their gear. Death from above this is not. It's only real notability is the early level it can be done at.

[Renduaz]

Just popping in to ask: Why is everybody taking this so seriously?

Renduaz made a funny invention that is technically correct by RAW (Albiet completely RAW over RAI, which contributes to the hilarity as I believe Tanarii tried to point out earlier (Though he could have been a little more clear)). If you're trying to argue that he's wrong based on logic or how you'd houserule it, you're not making your argument anywhere near to the same level that he is. Given how clever of a play this is, I think we can all assume (And Renduaz, confirm this for me if you'd like) that the creator knows how ridiculous this is.

All in all this is a great look at how the rules as written can do some funky things even in 5E, and exploits a fun loophole and gives us a hilarious and fun build. I'd never advocate actually bringing this into the game, but it serves as a great example and teaches some interesting and fun rules.

I laughed, I learned, I loved. I hope you all do too.

~Aerogellin

Well, of course it's ridiculous. Just as ridiculous as a magical plane of force manifesting out of magic and always keeping itself 3 feet above the ground, or follow someone when he gets 20 feet away from it. Hence why it's prone to ridiculous exploits.

[Sabeta]

Except they say nothing about not being able to either.

Precisely. That's Airbud. It doesn't matter what kind of spin you try to put on it, you're just here to try and exploit a nonexistent loophole in the rules.

The problem isn't with the definition of ground either. The problem is that you're trying to make both the disk and the ground do things they don't do. Fly.

[Renduaz]

Ground has two relevant definitions here.

One is "The Solid Surface of the Earth" which is ridiculously narrow. The logical breaks in this interpretation have already been covered.

and two is "A solid surface that can be walked upon."

Can you not walk upon a metal disc? Yes. Yes you can. Meaning it counts as ground. Can you not still walk upon it even if it's being moved?

Meaning as long as you don't try to go vertical, you're good.

It's not like this is even broken. You move 10 feet a round at the most. A shatter spell will wreck your day, and you can barely carry the party and their gear. Death from above this is not. It's only real notability is the early level it can be done at.

Ahem...Ahem...I wish the best of luck to the mage who can find, reach me and still cast spells at 10,000 feet above ground. Although a wildshape druid with flying form or someone who has his own method of achieving limitless height flight ( Unlike the Fly spell ) would probably succeed at confronting the pilot.

[druid91]

Precisely. That's Airbud. It doesn't matter what kind of spin you try to put on it, you're just here to try and exploit a nonexistent loophole in the rules.

The problem isn't with the definition of ground either. The problem is that you're trying to make both the disk and the ground do things they don't do. Fly.

Except there IS NO definition of ground in the rules. there is nothing whatsoever saying the ground has to be an immutable solid thing that will never ever move.

Your argument is just as much air bud as his is. The rules don't SAY the ground isn't immutable and solid, therefor it is.

Ground is something you can walk on. You can walk on a metal plate. Tensers Floating Disc triggers based on the ground that's underneath it. If it happens to be carrying that ground, so what? It doesn't stop being walkable terrain just because it's carried by a floating forcefield.

[Renduaz]

Precisely. That's Airbud. It doesn't matter what kind of spin you try to put on it, you're just here to try and exploit a nonexistent loophole in the rules.

The problem isn't with the definition of ground either. The problem is that you're trying to make both the disk and the ground do things they don't do. Fly.

If Airbud means "The rules won't stop it from working, but they don't state you can do this exact same thing" then yeah, that's like how half of the spells in 5e are being used. I want to use "Produce Flame" to light my torch. "Produce Flame" spell description doesn't explicitly state that it can light a torch. Air Bud logic! Or in other words, what we might know in the english language as "inference".

Also who says that ground and disks can't fly? The disk flies by it's own magic. It's hovering 3 feet above ground. That's literally "flying", just at a certain altitude. And as for the ground flying. If I wanted to cast Tenser's Disk on a house floor, will you let me? Now let's say a powerful mage comes by and blasts the house up into the sky. Guess what just happened to that piece of room floor that you acknowledged as ground? That's right, it rocketed up into flying thanks to a burst of magic. Which is what the device does.

[Renduaz]

Except there IS NO definition of ground in the rules. there is nothing whatsoever saying the ground has to be an immutable solid thing that will never ever move.

Your argument is just as much air bud as his is. The rules don't SAY the ground isn't immutable and solid, therefor it is.

Ground is something you can walk on. You can walk on a metal plate. Tensers Floating Disc triggers based on the ground that's underneath it. If it happens to be carrying that ground, so what? It doesn't stop being walkable terrain just because it's carried by a floating forcefield.

No, my argument about what qualifies as ground is RAI. The protester's arguments aren't:

"Standing in Tight Quarters" rule from page 30 of the DMG, the rules of lying prone, falling, and the descriptions of different form of ground for the purposes of the track skill, any surface that a creature can fight on, fall onto, lie prone on and/or leave tracks on on qualifies as "ground" for that creature.

Can I lie prone on my metallic surface? Can I fall down on it? There we go.

[Hrugner]

Soooo... what if the "ground" is a kite, hang glider, or a flag? That would make it self supporting which seems to be the major hurdle here.

[Tanarii]

Just popping in to ask: Why is everybody taking this so seriously?

Renduaz made a funny invention that is technically correct by RAW (Albiet completely RAW over RAI, which contributes to the hilarity as I believe Tanarii tried to point out earlier (Though he could have been a little more clear)).Yeah, thats how I took it. I honestly enjoyed reading it. It is a fun example of the idea that spells work in a predictable 'sciency' manner, and a player can apply that to analyze the effects, and extend it in an ingenious, unexpected and often very entertaining way. In some campaigns that's both appropriate and awesome!

It relies on at least one big assumption, that spells behave in a 'sciency' manner in the first place in the campaign. From there it often on a series of smaller assumptions or interpretations. In this case the big one is that 'ground' works a certain way.

To be fair to Renduaz, he's absolutely correct that I was being more than a little bit of 'that guy' in my posts. Because I wasn't sure if he was doing that and aware of his assumptions, or posting entirely in seriousness as if they were always true. Edit: and instead of just saying I enjoyed the post and pointing out the assumption, I mixed humor and snide-ness. Sorry Renduaz.


I laughed, I learned, I loved. I hope you all do too.sums up my feelings perfectly. :smallbiggrin:

[Renduaz]

Soooo... what if the "ground" is a kite, hang glider, or a flag? That would make it self supporting which seems to be the major hurdle here.

Those are supported by air rather than self-supporting. Are you talking about casting Tenser's Disk on those? I'm not sure which major hurdles you are referring.

[Renduaz]

Yeah, thats how I took it. I honestly enjoyed reading it. It is a fun example of the idea that spells work in a predictable 'sciency' manner, and a player can apply that to analyze the effects, and extend it in an ingenious, unexpected and often very entertaining way. In some campaigns that's both appropriate and awesome!

It relies on at least one big assumption, that spells behave in a 'sciency' manner in the first place in the campaign. From there it often on a series of smaller assumptions or interpretations. In this case the big one is that 'ground' works a certain way.

To be fair to Renduaz, he's absolutely correct that I was being more than a little bit of 'that guy' in my posts. Because I wasn't sure if he was doing that and aware of his assumptions, or posting entirely in seriousness as if they were always true. Edit: and instead of just saying I enjoyed the post and pointing out the assumption, I mixed humor and snide-ness. Sorry Renduaz.

sums up my feelings perfectly. :smallbiggrin:

No problem, everything is cool. It should probably be noted though that there's essentially no science involved here, the device works on 2 separate elements. The first is the disk's own magical properties per the description ( 3 feet levitation, 20feet+ following, ability to carry up to 500lbs on top of itself ), and second is the "ground" element. Now, that the metallic lower shell is a ground is actually explicitly supported by the handbook ( I just quoted the DMG in my last post ). What most people seem to have gripes about is whether a "ground reference" is still a "ground reference" if it's being carried by the disk's magic itself. To which I say that it isn't explicitly forbidden, nor is there a reason to assume it won't, and if you rule it doesn't, then you'd have to explain what happens instead, thereby inventing fictional attributes for the disk in the process which aren't covered. Which is why I say that it's a house ruling. You can allow it or not, but if you are, it's compatible with the rules.

If that final element is accepted, it works automatically just by the rules themselves, without any science.

[Tanarii]

When I say 'sciency', I mean treating magic spells as if they have properties which can then be analyzed and then extended in unique, not originally intended, ways. Or you can call it magic engineering if you prefer.

As opposed to an approach of cast spell, get exactly intended RAI effect out of spell, and not having them be extendable in use. A more push-button/get-result approach to magic.

[Renduaz]

When I say 'sciency', I mean treating magic spells as if they have properties which can then be analyzed and then extended in unique, not originally intended, ways. Or you can call it magic engineering if you prefer.

As opposed to an approach of cast spell, get exactly intended RAI effect out of spell, and not having them be extendable in use. A more push-button/get-result approach to magic.

I see, yes you are correct. I'm actually fascinated by "magic engineering" in D&D since it seems that much more rewarding than just flinging spells for damage or using as intended. When you think of it, that's something which the "Wizard" class, as opposed to sorcerer or warlock perhaps, is actually supposed to be doing. Delving and innovating on magical properties and applications for both new and existing spells. That's what they're actually meant to be doing professionally, moreso than just acting as ranged attackers for adventuring parties or employing known magic for comfort.

[JackPhoenix]

Now, that the metallic lower shell is a ground is actually explicitly supported by the handbook ( I just quoted the DMG in my last post ). What most people seem to have gripes about is whether a "ground reference" is still a "ground reference" if it's being carried by the disk's magic itself. To which I say that it isn't explicitly forbidden, nor is there a reason to assume it won't, and if you rule it doesn't, then you'd have to explain what happens instead, thereby inventing fictional attributes for the disk in the process which aren't covered. Which is why I say that it's a house ruling. You can allow it or not, but if you are, it's compatible with the rules.

I'm not sure what you've quoted, because page 30 in DMG doesn't say anything like that. In fact, the citations I've asked for in the first page of the thread concerning where do you get your definition of "ground" from are still missing. Maybe because there's nothing to cite, and the definition of ground you have to use to make this thing work doesn't exist by RAW?

Ground is NOT defined by 5e rules, thus you can't argue that RAW makes this idea works. It's up to every single GM to decide what is or isn't ground.

[sir_argo]

I don't think there is clear RAW on this. Crawford has said multiple times that D&D is not a science based game. However, I would base my ruling on how science works in this case.

I would rule that Tenser's Floating Disk cannot provide it's own "ground". Much the same way a hovercraft can't provide its own ground.

If you were in a hovercraft that hovered 3' off the "ground", it would work on real ground, the 2nd floor of a multi-storied building, the top of a dirigible 5,000' in the air, etc. Because all of those things get their support from something else. The ground essentially doesn't need support--it's the ground. The 2nd floor of a building gets support from the walls holding it up. The dirigible gets support from the air in the balloon. The hovercraft cannot have a wooden platform bolted to it, 3' below the fans, and stay aloft. Because the "push" from the hovercraft can't be against itself (bolting the wooden platform to the hovercraft makes it a single unit). The hovercraft would fall out of the sky.

Just like you can't produce upward push against yourself (please try, put your hand under your foot and try to lift yourself up into the air), you also can't push against yourself to achieve forward movement. Try this yourself. Put on some rollerblades, reach down and push on the back of the rollerblades and see if you can produce forward momentum. You can't.

Now... none of that is RAW, like I said. But I wouldn't allow this contraption to work by ruling that the "ground" can't be anything attached to the TFD. And before someone tries to put a third party inbetween (I attach a platform to the TFD, and have my buddy stand on that, while holding a shield under the TFD), I'd rule that you can't trace the support back to the TFD in any way.

[Cybren]

Except there IS NO definition of ground in the rules. there is nothing whatsoever saying the ground has to be an immutable solid thing that will never ever move.

Your argument is just as much air bud as his is. The rules don't SAY the ground isn't immutable and solid, therefor it is.

Ground is something you can walk on. You can walk on a metal plate. Tensers Floating Disc triggers based on the ground that's underneath it. If it happens to be carrying that ground, so what? It doesn't stop being walkable terrain just because it's carried by a floating forcefield.

Arguing a thin disc of metal suspended by tensers is "ground" is an incredibly bad faith argument not really worth addressing

[Renduaz]

I'm not sure what you've quoted, because page 30 in DMG doesn't say anything like that. In fact, the citations I've asked for in the first page of the thread concerning where do you get your definition of "ground" from are still missing. Maybe because there's nothing to cite, and the definition of ground you have to use to make this thing work doesn't exist by RAW?

Ground is NOT defined by 5e rules, thus you can't argue that RAW makes this idea works. It's up to every single GM to decide what is or isn't ground.

It's from this thread: www.giantitp.com/forums/showthread.php?385848-Disciple-of-Tenser-A-Guide-to-Maximum-Tenser-s-Floating-Disk-Utility , although this is indeed an earlier edition. But the definition of ground hasn't really changed. The same rules are right here - blog.onslow-web.co.uk/5e/gameplay/combat/movement.html, and they indicate the same thing. The top answer here ( rpg.stackexchange.com/questions/82302/what-is-the-ground ), inferring from the handbook references to "ground", also supports the notion that "ground" broadly refers to any solid continuous, contiguous surface on the planet.

Furthermore, if your DM rules that any kind of artificial material placed on the earth is "ground" ( Such as dungeon floor, house floor ), then so is a circular metallic disk. Even if ground isn't defined explicitly because the 5e handbook assumes you have a functional brain and will allow a player to, for instance, cast "Grease" on a surface that can be walked upon, fought upon, fallen upon, lied prone upon and so forth, it is defined in previous editions and it is inferred from everything else.

A DM can also decide not to let you do anything ground-related when you're in a dungeon or castle because he decided that "Ground" is only the Earth's soil. And then he can go even more preposterous and tell you that the earth's soil isn't ground because it moves along tectonic plates which are "swimming" around Toril's molten core and hanging in space. As long as your DM doesn't think that way, then the device works. But I already said from the start that a house rule can make it not work.

[LordCdrMilitant]

We need to better define the physical properties of Tenser's Floating Disk.

As a GM, I rule that a Tenser's Disk can transverse any surface I would not ordinarily require the players to test to move over. As a skimmer, it also ignores difficult/dangerous terrain.

It can fly above the deck of an airship, cross a paved bridge, or float happily at 3' above the floor/wall/ceiling of a space station in Low Earth Orbit. It can also submerge with it's operator, or enter tunnels and mines. It can also cross wooden footbridges and grated catwalks. A Tenser's Disk cannot cross a narrow plank over a chasm, balance atop a steel girder in a building under construction.

Ergo, would the players be required to test to stand on a 3' diameter table? I wouldn't require it, so I would allow the disk to float above the plate.

If we use the alternate definition of the "ground" being "the natural surface of the earth", then the system fails, but so does quite a lot of other magic. I don't like this definition, because it doesn't work in space, and if it can't explain what happens if I do it in deep space, I think it needs more definition.



As a GM, I rule that the "pounds" in the spell description refers to "pounds-force" and not "pounds-mass". While there is a stronger argument for it being pounds-mass, given the default abbreviation lb for pounds is referring to pounds-mass, there's less weirdness and ways to exploit the disk if we use pounds-force.

Under my definition, the disk is capable of exerting a maximum upwards force of 500lbf upon whatever is atop it. It will move to 3' above the ground its over, exerting a maximum of 500lbf until it reaches this point. If it would be required to exert more than 500lbf to reach this point in any amount of time, the spell fail. As, when in the cage, it would be unable to ever fully reach the 3' distance in any amount of time, the spell would fail.



If we use the alternate assumption that it's pounds-mass, we have to use other the conditions to determine the maximum acceleration the disk can undergo and make assumptions about the movement habits of the disk, and even then the spell has a breakdown if I want to use it on Ganymede. But, in the end, we still reach the same problem, namely it takes more force for the disk to reach 3' from it's ground than it can exert and the spell fails.



The city of brass can support TFD because it is supported by magic relative to the ground. The Airship is supported by heated gasses relative to the ground. The Airplane is lifted by air currents relative to the ground. In all those examples the TFD is sitting on something that by it's nature is already supported by magic or physics.

The shell you're referring to doesn't provide anything. It's a shell. It doesn't give the TFD anything to push off of except itself. Like magically grabbing one's own bootstraps to lift yourself into the air. It doesn't have lift from fast moving air, gass, or magic. It's just a piece of metal, sitting on the ground.

TFD doesn't do that. There's nothing in the rules that says it can do that. You're going Air Bud, to quote previous posters. You're going for a loophole and hoping that by ripping it open wide enough your theory will fit.

The bolded assertion is entirely incorrect. That's not how wings or gas bags work.

An airplane is flight cares not where the ground is, and neither does the airship's gas bag. To expound upon this, we'll look at an airplane in flight, and the physics that allow it to fly.

When an obstruction is placed in a free stream [aka, a wing moving through the air], the free stream has to go around it. In steady-state flow, at any given time t0, the fluid element at a location x, y has the same velocity as the fluid element at that location has at time t1. This means, if we draw streamlines in the flow representing the path a given fluid element will take through our region of space, they can be treated as uncrossable boundaries. The streamlines over an airfoil can be plotted, and from them, the velocity of the fluid element at that point determined. We can then use Bernoulli's equation, which relates the pressure, density, and velocity of a flow to determine the pressure at all point along the surface of the airfoil. For a plane in subsonic flight, we can treat the density as constant at all points in the flow. Pressure is force exerted over an area, and by integrating the pressure along the wing surfaces, we can determine the total force on the wing, and thus the amount of lift the wing produces. If the lift is equal to the weight of the plane, then the plane flies in steady, level flight. At no point does the plane care where the ground is.

Alternatively, we can look at the lift equation
Lift Force = 1/2 * Coefficient of Lift * Air Density * Velocity^2 * Wing Area.
The Cl is determined exclusively by the airfoil's shape, so we can see that, at no point does the plane actually care where the ground is.

Density in the standard atmosphere model is determined by altitude. However, this effect has nothing to do with the actual location of the ground, as you'll notice that the air is less dense in Denver than it is in San Diego

[Renduaz]

I don't think there is clear RAW on this. Crawford has said multiple times that D&D is not a science based game. However, I would base my ruling on how science works in this case.

I would rule that Tenser's Floating Disk cannot provide it's own "ground". Much the same way a hovercraft can't provide its own ground.

If you were in a hovercraft that hovered 3' off the "ground", it would work on real ground, the 2nd floor of a multi-storied building, the top of a dirigible 5,000' in the air, etc. Because all of those things get their support from something else. The ground essentially doesn't need support--it's the ground. The 2nd floor of a building gets support from the walls holding it up. The dirigible gets support from the air in the balloon. The hovercraft cannot have a wooden platform bolted to it, 3' below the fans, and stay aloft. Because the "push" from the hovercraft can't be against itself (bolting the wooden platform to the hovercraft makes it a single unit). The hovercraft would fall out of the sky.

Just like you can't produce upward push against yourself (please try, put your hand under your foot and try to lift yourself up into the air), you also can't push against yourself to achieve forward movement. Try this yourself. Put on some rollerblades, reach down and push on the back of the rollerblades and see if you can produce forward momentum. You can't.

Now... none of that is RAW, like I said. But I wouldn't allow this contraption to work by ruling that the "ground" can't be anything attached to the TFD. And before someone tries to put a third party inbetween (I attach a platform to the TFD, and have my buddy stand on that, while holding a shield under the TFD), I'd rule that you can't trace the support back to the TFD in any way.

False analogy. The hovercraft is also supported by air, and generates lift by pushing air down, which has nothing to do with the ground. Not to mention the hovercraft in your example would still work if the air current's thrust on the hovercraft was greater than the pressure it exerted on the wood, which it probably is. In fact, hovercrafts work by having a "skirt" placed under them to trap the air current and lift themselves up. Absolutely none of that is relevant to TFD though, since a hovercraft doesn't care about having a ground below it while TFD does, and a hovercraft works according to physics while TFD works according to magic rules.

TFD can "lift itself" because it's magic. How does it hover 3 feet above the ground? Unlike any other object in real life, it doesn't do so through any kind of physical force, it simply does, because that's what the spell description says. How does the disk move forward when the player is away from it? Again, innate magic. Jesus christ, why do people keep insisting on these completely erronenous analogies to dismiss the idea? It's been explained only a few posts ago.

Your "lift yourself with a hand below your foot" would've worked under 2 very specific conditions, do you want to know which? That as long I did so, using my hands as a ground reference, I would also be pulled to another person in any direction if he was ever more than 20 feet away from it. In that case, if he inserted me inside a chamber, attached a 20 feet long board to that chamber, and sat upon it at a 130 degree angle, then I would slowly start drifting higher and higher and forward like an airplane. So it's a good thing my body doesn't have these magical conditions, but Tenser's Disk does.

[JackPhoenix]

It's from this thread: www.giantitp.c(o)m/forums/showthread.php?385848-Disciple-of-Tenser-A-Guide-to-Maximum-Tenser-s-Floating-Disk-Utility , although this is indeed an earlier edition. But the definition of ground hasn't really changed. The same rules are right here - blog.onslow-web.co.uk/5e/gameplay/combat/movement.html, and they indicate the same thing. The top answer here ( rpg.stackexchange.c(o)m/questions/82302/what-is-the-ground ), inferring from the handbook references to "ground", also supports the notion that "ground" broadly refers to any solid continuous, contiguous surface on the planet.

Furthermore, if your DM rules that any kind of artificial material placed on the earth is "ground" ( Such as dungeon floor, house floor ), then so is a circular metallic disk. Even if ground isn't defined explicitly because the 5e handbook assumes you have a functional brain and will allow a player to, for instance, cast "Grease" on a surface that can be walked upon, fought upon, fallen upon, lied prone upon and so forth, it is defined in previous editions and it is inferred from everything else.

A DM can also decide not to let you do anything ground-related when you're in a dungeon or castle because he decided that "Ground" is only the Earth's soil. And then he can go even more preposterous and tell you that the earth's soil isn't ground because it moves along tectonic plates which are "swimming" around Toril's molten core and hanging in space. As long as your DM doesn't think that way, then the device works. But I already said from the start that a house rule can make it not work.

The first link doesn't work, and even if it did, it would be irrelevant for the discussion, as we're not talking about 3.5e (I presume it's 3.5e). The second address doesn't contain any definition of ground. The discussion in the last address actualy mentions that there's no RAW definition of ground, any instances mentioning "ground" in the rules use a plain language and are context- and GM-dependent. So while you're allowed to use whatever ruling you want to make your idea work if you're the GM, you can't argue that it's in any way RAW. If the GM rules that "any kind of artificial material placed on the earth is "ground"", it has no bearing on his ruling if that same material is still "ground" when it's no longer placed on the earth.

So, not only isn't a house rule needed to make it not work, the interpretation of the (non-existing) rules that make it work is also a house rule (it's not, ruling is not the same thing as house rule, but that just means you're using the wrong term).

[StoicLeaf]

Cute idea but won't work. RAW or RAI.

To be brief:

1) You keep linking to sites that do nothing to help you. Ground isn't defined in the 5e manual. Especially not for such a niche case. Who's to say it isn't tracking the ground your base shell is lying on?
2) The casting of the disc will require unoccupied space. You need to be able to see this space. If your construct is a tight shell you won't be recasting it, if it's a loose and more open construct then it won't be stable.
3) physics. even if you tie a scrawny 100 pound weakling wizard to a stick 21ft away from the disc to make it move, the leverage will overburden the 500 pound limit on the disc.
4) tenser's disc is a level 1 spell that can be cast as a ritual. Now depending on how bullheaded you want to be, RAW would surely imply that a level 1 spell cannot do something that a higher level spell does. Firebolt <=> fireball, for example. Or minor illusion <=> major illusion. As such, tenser cannot move other objects blocking its path. Your upper shell will hinder it's movement.

[LordCdrMilitant]

The first link doesn't work, and even if it did, it would be irrelevant for the discussion, as we're not talking about 3.5e (I presume it's 3.5e). The second address doesn't contain any definition of ground. The discussion in the last address actualy mentions that there's no RAW definition of ground, any instances mentioning "ground" in the rules use a plain language and are context- and GM-dependent. So while you're allowed to use whatever ruling you want to make your idea work if you're the GM, you can't argue that it's in any way RAW. If the GM rules that "any kind of artificial material placed on the earth is "ground"", it has no bearing on his ruling if that same material is still "ground" when it's no longer placed on the earth.

So, not only isn't a house rule needed to make it not work, the interpretation of the (non-existing) rules that make it work is also a house rule (it's not, ruling is not the same thing as house rule, but that just means you're using the wrong term).

It's equally at the discretion of the GM to define the ground as exclusively the natural surface of the earth. I, as a GM, don't like this interpretation, as it means that you can't use spells on a ship, in a tunnel, on the second floor of a house, etc. RAI, you can cast magic in a dungeon, right?

I don't subscribe to the definition of the ground as "the natural surface of the earth" because 1: Whats "natural" can go **** itself, and 2: I can't use the definition if we're in interstellar space. Or at least, we have to define it more, such as "the natural point upon the body exerting the greatest gravitational effect upon the object at which the normal force exerted by the natural materials of the body counteracts the gravitational force of the body"

However, the machine still fails, I think, as I explained in my earlier post.

[Renduaz]

The first link doesn't work, and even if it did, it would be irrelevant for the discussion, as we're not talking about 3.5e (I presume it's 3.5e). The second address doesn't contain any definition of ground. The discussion in the last address actualy mentions that there's no RAW definition of ground, any instances mentioning "ground" in the rules use a plain language and are context- and GM-dependent. So while you're allowed to use whatever ruling you want to make your idea work if you're the GM, you can't argue that it's in any way RAW. If the GM rules that "any kind of artificial material placed on the earth is "ground"", it has no bearing on his ruling if that same material is still "ground" when it's no longer placed on the earth.

So, not only isn't a house rule needed to make it not work, the interpretation of the (non-existing) rules that make it work is also a house rule (it's not, ruling is not the same thing as house rule, but that just means you're using the wrong term).

Replace the (o) with "o" in the first link. I'll give it to you that "Ground" isn't on it's own defined in RAW. So your GM could, technically, rule ground to be whatever he wants it to be ( Could only be made of lemons too, since hey, it ain't in RAW! ). But we at least know that Jeremy Crowford and Mike Mearls let players cast spells with a "ground" tag while in dungeons or houses or bridges or any type of floors in campaigns that they DM, so I think it should at least be abundantly logical that "Artificially placed slabs or tiles of matter" that you can lie prone on, fall upon, put something on, walk upon and so forth also qualify as ground, which makes a metallic or wooden slab ground too. Then we need to discuss "flying ground", in which I don't think there is any known precedent for a DM to forbid someone from casting Grease or something else just because a battle takes place in a floating platform or airship.

So up until this point a DM would have to make a completely unprecedented ruling, both officially and unofficially in order to object. The only ruling which wouldn't be irrational one way or the other is whether "Tenser's Disk can carry it's own ground". And since nothing says it can't, you'd need to invent a new ruling about TFD to reject it. Whereas if you allow the device, you aren't inventing a new ruling, you're simply going by the existing rules in which the disk always floats 3 feet above it's ground, and you don't change anything about that just because the ground is carried.


Cute idea but won't work. RAW or RAI.

To be brief:

1) You keep linking to sites that do nothing to help you. Ground isn't defined in the 5e manual. Especially not for such a niche case. Who's to say it isn't tracking the ground your base shell is lying on?
2) The casting of the disc will require unoccupied space. You need to be able to see this space. If your construct is a tight shell you won't be recasting it, if it's a loose and more open construct then it won't be stable.
3) physics. even if you tie a scrawny 100 pound weakling wizard to a stick 21ft away from the disc to make it move, the leverage will overburden the 500 pound limit on the disc.
4) tenser's disc is a level 1 spell that can be cast as a ritual. Now depending on how bullheaded you want to be, RAW would surely imply that a level 1 spell cannot do something that a higher level spell does. Firebolt <=> fireball, for example. Or minor illusion <=> major illusion. As such, tenser cannot move other objects blocking its path. Your upper shell will hinder it's movement.

1) The spell description. Tenser's Disk moves up stairs. If it was tracking the stairbase or the soil or the floor beneath the staircase instead, it wouldn't be able to move up the stairs. It tracks each new stair as it's ground reference when it reaches it, maintaining 3 feet elevation above it.

2) I see that you haven't read the OP. There's a hatch or a manhole for that.

3) What's your math on that? Besides, a straight plank isn't how it works.

4 ) But it isn't moving objects blocking it's path. It carries an object, which the spell description clearly says it can do. And that object is the upper casing, being tied to the lower casing.

[LordCdrMilitant]

1) The spell description. Tenser's Disk moves up stairs. If it was tracking the stairbase or the soil or the floor beneath the staircase instead, it wouldn't be able to move up the stairs. It tracks each new stair as it's ground reference when it reaches it, maintaining 3 feet elevation above it.

2) I see that you haven't read the OP. There's a hatch or a manhole for that.

3) What's your math on that? Besides, a straight plank isn't how it works.

4 ) But it isn't moving objects blocking it's path. It carries an object, which the spell description clearly says it can do. And that object is the upper casing, being tied to the lower casing.

Actually, he brings up an interesting point about the Tenser's Disk. What's it's resistance to rotation? If I apply a moment of 5000lbf-ft to it [it's 500lbf load mounted on a 10ft massless stick attached to the disk], what happens to it?

This might be useful to consider when I try to use it to build a gun drone, or mobile ballista platform, or a myriad of other applications. If it has infinite rotational inertia, think of all the creative things you could do with it!

[Renduaz]

We need to better define the physical properties of Tenser's Floating Disk.

As a GM, I rule that a Tenser's Disk can transverse any surface I would not ordinarily require the players to test to move over. As a skimmer, it also ignores difficult/dangerous terrain.

It can fly above the deck of an airship, cross a paved bridge, or float happily at 3' above the floor/wall/ceiling of a space station in Low Earth Orbit. It can also submerge with it's operator, or enter tunnels and mines. It can also cross wooden footbridges and grated catwalks. A Tenser's Disk cannot cross a narrow plank over a chasm, balance atop a steel girder in a building under construction.

Ergo, would the players be required to test to stand on a 3' diameter table? I wouldn't require it, so I would allow the disk to float above the plate.

If we use the alternate definition of the "ground" being "the natural surface of the earth", then the system fails, but so does quite a lot of other magic. I don't like this definition, because it doesn't work in space, and if it can't explain what happens if I do it in deep space, I think it needs more definition.



As a GM, I rule that the "pounds" in the spell description refers to "pounds-force" and not "pounds-mass". While there is a stronger argument for it being pounds-mass, given the default abbreviation lb for pounds is referring to pounds-mass, there's less weirdness and ways to exploit the disk if we use pounds-force.

Under my definition, the disk is capable of exerting a maximum upwards force of 500lbf upon whatever is atop it. It will move to 3' above the ground its over, exerting a maximum of 500lbf until it reaches this point. If it would be required to exert more than 500lbf to reach this point in any amount of time, the spell fail. As, when in the cage, it would be unable to ever fully reach the 3' distance in any amount of time, the spell would fail.



If we use the alternate assumption that it's pounds-mass, we have to use other the conditions to determine the maximum acceleration the disk can undergo and make assumptions about the movement habits of the disk, and even then the spell has a breakdown if I want to use it on Ganymede. But, in the end, we still reach the same problem, namely it takes more force for the disk to reach 3' from it's ground than it can exert and the spell fails.




The bolded assertion is entirely incorrect. That's not how wings or gas bags work.

An airplane is flight cares not where the ground is, and neither does the airship's gas bag. To expound upon this, we'll look at an airplane in flight, and the physics that allow it to fly.

When an obstruction is placed in a free stream [aka, a wing moving through the air], the free stream has to go around it. In steady-state flow, at any given time t0, the fluid element at a location x, y has the same velocity as the fluid element at that location has at time t1. This means, if we draw streamlines in the flow representing the path a given fluid element will take through our region of space, they can be treated as uncrossable boundaries. The streamlines over an airfoil can be plotted, and from them, the velocity of the fluid element at that point determined. We can then use Bernoulli's equation, which relates the pressure, density, and velocity of a flow to determine the pressure at all point along the surface of the airfoil. For a plane in subsonic flight, we can treat the density as constant at all points in the flow. Pressure is force exerted over an area, and by integrating the pressure along the wing surfaces, we can determine the total force on the wing, and thus the amount of lift the wing produces. If the lift is equal to the weight of the plane, then the plane flies in steady, level flight. At no point does the plane care where the ground is.

Alternatively, we can look at the lift equation
Lift Force = 1/2 * Coefficient of Lift * Air Density * Velocity^2 * Wing Area.
The Cl is determined exclusively by the airfoil's shape, so we can see that, at no point does the plane actually care where the ground is.

Density in the standard atmosphere model is determined by altitude. However, this effect has nothing to do with the actual location of the ground, as you'll notice that the air is less dense in Denver than it is in San Diego

It does reach that point in the cage though. First you cast TFD on the lower casing, and it's 3 feet above it, at the point. Now we place the upper shell casing on it, which TFD "carries" ( Which is what it does ) by exerting much less than 500lbf on it. So far so good right? Then we simply attach the upper shell to the lower. Tenser's Disk is still at the same point it was when it was first cast, still holding the upper shell. Now when I start angling it's "follow" ability ( 20 feet range ) upward, it pushes up on the upper shell ( Just like it does when it carries loot up slopes or stairs ), which in turn also lifts up the lower shell. Where's the problem here?

[LordCdrMilitant]

It does reach that point in the cage though. First you cast TFD on the lower casing, and it's 3 feet above it, at the point. Now we place the upper shell casing on it, which TFD "carries" ( Which is what it does ) by exerting much less than 500lbf on it. So far so good right? Then we simply attach the upper shell to the lower. Tenser's Disk is still at the same point it was when it was first cast, still holding the upper shell. Now when I start angling it's "follow" ability ( 20 feet range ) upward, it pushes up on the upper shell ( Just like it does when it carries loot up slopes or stairs ), which in turn also lifts up the lower shell. Where's the problem here?

It doesn't naturally try to take off to chase you. That's fairly explicit in the rule. If you fly 50ft in the air, it will move as close as it can to being 20ft from you while still being 3' from the ground, and so be directly beneath you. It will move towards you, remaining 3' above it's bottom plate at all times, and never lifting the upper plate in this case.

It can't move upwards unless the plates are closer than 3'1", and if they're closer than 3'1", the spell fails.

[Renduaz]

Actually, he brings up an interesting point about the Tenser's Disk. What's it's resistance to rotation? If I apply a moment of 5000lbf-ft to it [it's 500lbf load mounted on a 10ft massless stick attached to the disk], what happens to it?

This might be useful to consider when I try to use it to build a gun drone, or mobile ballista platform, or a myriad of other applications. If it has infinite rotational inertia, think of all the creative things you could do with it!

While since if you put all of your loot at the edge it arguably won't flip, and the description says "This spell creates a circular, horizontal plane of force, 3 feet in diameter and 1 inch thick, that floats 3 feet above the ground", meaning it's always in this state unless stated otherwise, then it probably has infinite magical resistance to rotation.

[Renduaz]

It doesn't naturally try to take off to chase you. That's fairly explicit in the rule. If you fly 50ft in the air, it will move as close as it can to being 20ft from you while still being 3' from the ground, and so be directly beneath you. It will move towards you, remaining 3' above it's bottom plate at all times, and never lifting the upper plate in this case.

http://i.imgur.com/cVFCtU7.png

That's why I'm using the chair contraption to place myself 25 feet away at an angle ( By pulling the chair up for the takeoff ). Tenser's Disk will, as you say, move as close as it can to being 20 feet away from me. And the closest way to me is a straight line, so it will start moving forward and up ( like an airplane on a runway ), but since I also get further away at the same angle whenever it does so, it will keep doing it perpetually, thus flying.

By the way, Tenser's Disk doesn't attempt to remain 3' above it's ground at all times. It can actually cross elevation changes of up to 10'. For example if a player climbed up to a stage that was 8', from ground tenser's disk is currently on, and moved more than 20 feet away it, Tenser's disk will levitate the whole 8' up to the stage and then follow the player again.

[LordCdrMilitant]

That's why I'm using the chair contraption to place myself 25 feet away at an angle ( By pulling the chair up for the takeoff ). Tenser's Disk will, as you say, move as close as it can to being 20 feet away from me. And the closest way to me is a straight line, so it will start moving forward and up ( like an airplane on a runway ), but since I also get further away at the same angle whenever it does so, it will keep doing it perpetually, thus flying.



This spell creates a circular, horizontal plane of force, 3 feet in diameter and 1 inch thick, that floats 3 feet above the ground in an unoccupied space of your choice that you can see within range.
The disk remains for the duration, and can hold up to 500 pounds. If more weight is placed on it, the spell ends, and everything on the disk falls to the ground.

The disk is immobile while you are within 20 feet of it. If you move more than 20 feet away from it, the disk follows you so that it remains within 20 feet of you. It can more across uneven terrain, up or down stairs, slopes and the like, but it can’t cross an elevation change of 10 feet or more. For example, the disk can’t move across a 10-foot-deep pit, nor could it leave such a pit if it was created at the bottom.

If you move more than 100 feet from the disk (typically because it can’t move around an obstacle to follow you), the spell ends.


It doesn't attempt to move upwards. It moves laterally, always 3' above its ground, and gets as close to you as it can.


Anyway, I'm fairly certain I can get my characters a bomber if they desired one at level 1. Maybe only a little magic required. The GM might get angry at me though. What's the best way to make something spin quickly and cheaply for a level 1 character? Alternatively, Hot-Air Balloons aren't very difficult, considering that we have "produce flame". Alternatively, with electric power from shock-based cantrips you could produce hydrogen for your airship, fill up your gas bag, and set off on your Hindenburg adventure!

[StoicLeaf]

1) But don't you see this is exactly why a definition of ground would be helpful? One which the game does not provide. RAW states that the DM decides in such cases.

2) I read the op, I just don't think it's going to be as easy as you think it will be.

3) I'm not here to do your maths. I don't think you're going to be able to build all of that safely with medieval supplies in under 500 pounds.

4 ) And it can't move the upper casing because that's being tied down by the lower casing. Think about it, you've put the disc in a cage. With regards to spell levels and their functionality: levitate is a level 2 spell that requires conc and needs you to somehow creatively add horizontal movement. straight up flying is a level 3 spell, also conc. You're not going to get flying, concentration free, for a level 1 slot.

I honestly don't understand why you're so adamant about this being RAW.
I mean it's not called tenser's flying disc for a reason.

[Renduaz]

It doesn't attempt to move upwards. It moves laterally, always 3' above its ground, and gets as close to you as it can.

Except it does in the spell description unless the elevation change is equal or more than 10 feet.


1) But don't you see this is exactly why a definition of ground would be helpful? One which the game does not provide. RAW states that the DM decides in such cases.

2) I read the op, I just don't think it's going to be as easy as you think it will be.

3) I'm not here to do your maths. I don't think you're going to be able to build all of that safely with medieval supplies in under 500 pounds.

4 ) And it can't move the upper casing because that's being tied down by the lower casing. Think about it, you've put the disc in a cage. With regards to spell levels and their functionality: levitate is a level 2 spell that requires conc and needs you to somehow creatively add horizontal movement. straight up flying is a level 3 spell, also conc. You're not going to get flying, concentration free, for a level 1 slot.

I honestly don't understand why you're so adamant about this being RAW.
I mean it's not called tenser's flying disc for a reason.

4) Why not? It works almost exactly like the Hydrogen cell of a Zeppelin.

I'm not adamant about it being RAW, only adamant about it not being contradicted by RAW, and reasonably allowed by inference.

[LordCdrMilitant]

Except it does in the spell description unless the elevation change is equal or more than 10 feet.



Where does it say that? I just posted the exact passage.

It starts by saying it stays 3' above the ground. Then, it says it can climb stairs and ramps. Note that while climbing stairs and ramps and and crossing obstacles it remains 3' from the ground. It also says it cannot cross an obstacle more than 10' tall, implying the furthest distance any part of the disk can be from the ground when obstacle crossing is 13'

[Renduaz]

Where does it say that? I just posted the exact passage.

If you move more than 20 feet away from it, the disk follows you so that it remains within 20 feet of you. It can more across uneven terrain, up or down stairs, slopes and the like, but it can’t cross an elevation change of 10 feet or more. For example, the disk can’t move across a 10-foot-deep pit, nor could it leave such a pit if it was created at the bottom.

The disk is immobile while you're within 20 feet. If you start going up stairs somewhere, as soon as you're more than 20 feet away, the spell will move forward and up to reach you. Or if you just cross a 8-foot-deep pit to the other side, or a 8-foot barrier, it will also rise up or down when you're 20 feet away to follow you.

Imagine that I'm on a 25-feet long staircase, each stair 1 feet long. The disk is still at the floor, next to the first step. I reach the 20th stair. The disk moves up and forward to climb on the first stair. Now imagine that when the disk just did so, I go up another stair. The disk once again moves at an angle, forward and upward to reach me. Now imagine it could never reach me and had to keep doing it infinitely. That's how my contraption works with the chair elevated at an angle of 20+ feet away from the disk.

[LordCdrMilitant]

If you move more than 20 feet away from it, the disk follows you so that it remains within 20 feet of you. It can more across uneven terrain, up or down stairs, slopes and the like, but it can’t cross an elevation change of 10 feet or more. For example, the disk can’t move across a 10-foot-deep pit, nor could it leave such a pit if it was created at the bottom.

The disk is immobile while you're within 20 feet. If you start going up stairs somewhere, as soon as you're more than 20 feet away, the spell will move forward and up to reach you. Or if you just cross a 8-foot-deep pit to the other side, or a 8-foot barrier, it will also rise up or down when you're 20 feet away to follow you.

No, it will move along the ground and up the stairs, remaining 3' above the ground and then the stair it is using as it's reference point.

It takes the best route to within 20' of you it can, obeying the conditions of it's movement:
3' from at least some part of the ground.
Can't cross obstacles 10' tall or more.

Because there's no ramp or stair or other slope to allow it to ascend to follow you, it doesn't attempt to move upwards, only move laterally, and be as close to you as possible. It therefore doesn't move the upper plate upwards, and therefore doesn't move the lower plate it's standing on upwards, and doesn't fly.

[Renduaz]

No, it will move along the ground and up the stairs, remaining 3' above the ground and then the stair it is using as it's reference point.

It takes the best route to within 20' of you it can, obeying the conditions of it's movement:
3' from at least some part of the ground.
Can't cross obstacles 10' tall or more.

It can't cross an obstacle of 10' tall or more. It can cross a 8' tall obstacle. If I climbed up to a new elevation 8' taller than my previous one, the disk would levitate upwards 3,4,5,6,7,8 feet from it's ground before reaching the new surface, thus breaking your notion of "always remaining 3' above the ground". It will, at the moment of it's ascent, hover up to 8' feet over it's first ground reference, before it could reach the new one in a vertical climb.

It doesn't need a ramp or stair, TFD is capable of rising up to 10 feet from it's ground reference if it needs to do so in order to follow the player. So when I'm in my chair, it will attempt to rise up more than 3feet above the lower casing ( it's ground reference ) in order to reach my new elevation, and by doing so also push the upper casing up, pushing me up, making it keep trying to rise to my elevation perpetually, while the lower casing also continues rising with the whole thing, making sure it's never 10 feet above it's ground. Perfect.

[LordCdrMilitant]

It can't cross an obstacle of 10' tall or more. It can cross a 8' tall obstacle. If I climbed up to a new elevation 8' taller than my previous one, the disk would levitate upwards 3,4,5,6,7,8 feet from it's ground before reaching the new surface, thus breaking your notion of "always remaining 3' above the ground". It will, at the moment of it's ascent, hover up to 8' feet over it's first ground reference, before it could reach the new one in a vertical climb.

It doesn't need a ramp or stair, TFD is capable of rising up to 10 feet from it's ground reference if it needs to do so in order to follow the player. So when I'm in my chair, it will attempt to rise up more than 3feet above the lower casing ( it's ground reference ) in order to reach my new elevation, and by doing so also push the upper casing up, pushing me up, making it keep trying to rise to my elevation perpetually, while the lower casing also continues rising with the whole thing, making sure it's never 10 feet above it's ground.

No, it won't, because it doesn't move upwards unless prompted to by an obstacle. You being above it isn't an obstacle. Note that the passage where it allows it to override the 3' rule specifies that it gets to do so when attempting to cross an elevation difference.

When it evaluates the path it can take to you in this machine, it can't find a path to within 20' of you [because it isn't allowed to be at any of the position within 20' of you], and so will move to the point closest to a point within 20' of you, never attempting to lift itself up above 3' unless there is a location within 20' of you it can stop at where it is 3' above the ground.

Basically, the Tenser's Disk doesn't know it can fly using the cage around it to get to you, so it won't try to.

If you built the machine in the air, and had perfect machining tolerances, I guess it could conceivably maintain steady altitude if you rule it exerts no force on the ground, but could under no circumstance climb or descend.

[Renduaz]

No, it won't, because it doesn't move upwards unless prompted to by an obstacle. You being above it isn't an obstacle.

Again, doesn't matter. You said it yourself, it always tires to take the closest route to the player when the player is more than 20 feet away. Moving 3 feet laterally isn't the closest route. And the spell description doesn't say "unless prompted by an obstacle", it only says that it can't cross an elevation change of 10' feet or more ( But can change elevation when it's less ), and the quickest path to me would be an elevation change of above 3feet and moving forward at an angle.

Regardless, a very minor objection if that's the only remaining element which bothers you. The rim of the shell would count as an obstacle. Or if you want to get really obvious, just attach a metal partition to the outer shell, in the same direction as the chair. That basically registers the same as a less than 10' feet wall which the disk's "Forward" motion will try to rise up over, but then of course the obstacle also keeps rising up when it does so, and thus powering the entire mechanism all over again with a perfectly obvious obstacle in place. Either way it still works.

"Basically, the Tenser's Disk doesn't know it can fly using the cage around it to get to you, so it won't try to." - It doesn't have to know it can fly, it magically knows where I am ( And thereby follows me ), so all it would have to know is that I'm 25 feet away at a 130 degree angle upwards, to make it begin magically moving at a direct line towards me. It doesn't know what it's "allowed" unless it's a 10' obstacle. It knows it's allowed to rise above the ground up to that height to match a player's position. Tenser's Disk perceives the following:

Ground ( lower casing ) = 3 feet below me
Carrying object ( Upper casing ) = Exerting X lbf on me
Player = 25 feet away, start following to get as close as possible
Obstacles = I can't cross an elevation change of 10' or more. I'm currently 3' above my ground, so I can rise and move forward within my range. Is the ground still less than 10' below me? Then I can keep going.

[LordCdrMilitant]

Again, doesn't matter. You said it yourself, it always tires to take the closest route to the player when the player is more than 20 feet away. Moving 3 feet laterally isn't the closest route. And the spell description doesn't say "unless prompted by an obstacle", it only says that it can't cross an elevation change of 10' feet or more ( But can change elevation when it's less ), and the quickest path to me would be an elevation change of above 3feet and moving forward at an angle.

Regardless, a very minor objection if that's the only remaining element which bothers you. The rim of the shell would count as an obstacle. Or if you want to get really obvious, just attach a metal partition to the outer shell, in the same direction as the chair. That basically registers the same as a less than 10' feet wall which the disk's "Forward" motion will try to rise up over, but then of course the obstacle also keeps rising up when it does so, and thus powering the entire mechanism all over again with a perfectly obvious obstacle in place. Either way it still works.


It has very specific pathing restrictions, and it always moves according to those restrictions. Have you every played a Real Time Strategy game?

The disk, at every instant, evaluates paths to the target it can legally follow. Then, it picks the best path, and moves along it.

If you have a platform for it to arrive at, it still can't find a path because it would have to transverse an obstacle more than 10' high to get to the landing platform.


However If you connected your chair to the lower platform via a complete viable track the disk can follow, it will be able to move to reach you, and will attempt to do so.

But there's another problem here, and that is, if your mechanism supporting your lower plate is blocking the disk's path to your chair, it won't move. But, if you don't have a bar there, the disk will just slide out from underneath the upper plate. If you use ropes, then the machine will flip over.

Edit: I think I found a way for it to work, but I'll need to check the weights and moment balances to ensure the machine won't break down and won't be too heavy. I'll do it later, because I'm going to go actually play some D&D now, and work out how to achieve orbit at level 6.

[Renduaz]

It has very specific pathing restrictions, and it always moves according to those restrictions. Have you every played a Real Time Strategy game?

The disk, at every instant, evaluates paths to the target it can legally follow. Then, it picks the best path, and moves along it.

If you have a platform for it to arrive at, it still can't find a path because it would have to transverse an obstacle more than 10' high to get to the landing platform.


However If you connected your chair to the lower platform via a complete viable track the disk can follow, it will be able to move to reach you, and will attempt to do so.

But there's another problem here, and that is, if your mechanism supporting your lower plate is blocking the disk's path to your chair, it won't move. But, if you don't have a bar there, the disk will just slide out from underneath the upper plate.

I have to sleep so I'll respond to this later, but I must say I do enjoy this conversation as a technical challenge the most so far. In the meantime I'll just say that the disk in your scenario would move, but rather only upward, not forward. It will count the shell's rim blocking it's path as a heightened obstacle ( The rim of the shell jutting up from the lower casing to connect with the upper casing ), and since that rim is less than 10' feet, it will attempt to rise above it, but therefore also raise the upper casing, thus the rim ( obstacle ), and the lower casing, and keep rising perpetually but without moving forward for the takeoff. But I don't think that's really necessary at all, yet as I said, I will continue at another time from now.

Edit: Alright, I've had some time to think about this and realized a few things. First of all, if the disk's pathfinding works the way you suggest, you wouldn't need a connection all the way to the chair, you'd only need the shell's diameter to be slightly wider than the disk's 3', which it already is in order to encapsulate the disk. Think about it, if a disk is in a hallway, and there's 10' length of floor in front of it before there is a deep pit, and the player crosses over the pit and gets 20 feet away, does the disk just remain in place because it knows it will encounter the pit eventually, or does it first traverse the 10' feet of floor that it can in order to get close to the player, and only stopping when it reaches the edge of the pit or somewhere near it? The rules suggest the latter, that the disk continues moving along a viable path until it encounters the obstacle, not that it would stop 10' away from the pit because it knows there's a pit up ahead. It gets as close to the player over a viable path for as long as it can, and stops as soon as it reaches the obstacle.

So you see, if your shell is 4' in diameter for example, the disk perceives that it still has 1' distance to move forward closer to the player within it's own shell ( Over the lower casing which is it's ground ), before reaching the obstacle of either the shell's rim or the open air and elevation change outside of it. Now the real question is what happens to the shell when the disk makes that movement forward. That would depend on how much friction does the upper surface of the disk, as a plane of force, have. We actually already know that it isn't frictionless, because if it was, it wouldn't be able to carry loot. Everything would just slide away as soon as the disk follows the player. But it doesn't, so we know that the disk's upper surface has enough friction to keep the objects placed on it attached to it while it follows the player. Now for all we know, it could have either the friction of stone or of industrial glue ( I.E, I could put a ball on it and the ball would never roll off the disk, the disk will keep magically carrying it as it moves forward like it's intended to ) or infinite magical friction or something else. But we also know it can't be low friction, like an oily surface for example, or otherwise the majority of loot would be sliding off the disk when a player uses it.

Put some kind of object on the back of your hand, imagine it as the upper surface of the disk, and start moving your hand back and forth. Most hard objects are never going to slide across the back of your hand unless you will move your hand extremely fast back and forth, since there is enough friction to keep them attached.

What would happen then is this - Tenser's Disk, within it's shell, perceives the player is more than 20 feet away and that it can still move 1' forward before reaching an obstacle and having to stop. It begins to move 1' forward across it's ground ( the lower shell ), but also moves the upper shell which is on it 1' forward since it's carried by friction, which also moves the lower casing forward, causing Tenser's Disk to perpetually be 1' distance away from it's obstacle, and always trying to traverse the viable path it has left, except it never will because it's pushing it's own obstacle forward like a horse with a carrot dangling in front of it's mouth. The device still works.

[Hrugner]

Those are supported by air rather than self-supporting. Are you talking about casting Tenser's Disk on those? I'm not sure which major hurdles you are referring.

They aren't supported by the disc which is apparently a problem for some people. If we're ruling you could put one in the basket of a hot air balloon, then clearly we could put one on something else that maintains elevation due to air pressure. hanging a flag from the chair at the front of your disc would give you a surface supported by something other than the disk itself that would also provide a path up to the pilot of the craft which is also apparently necessary.

[JackPhoenix]

They aren't supported by the disc which is apparently a problem for some people. If we're ruling you could put one in the basket of a hot air balloon, then clearly we could put one on something else that maintains elevation due to air pressure. hanging a flag from the chair at the front of your disc would give you a surface supported by something other than the disk itself that would also provide a path up to the pilot of the craft which is also apparently necessary.

If the flag hangs from the chair on the disc thing, it's supported by the disc, not by air. It's essentialy the same as the bottom side of the proposed shell case, only somewhat lighter and less durable.

[Matrix_Walker]

Whether you agree or disagree with the design, assumptions or definitions, this is an obvious attempt to circumvent the RAI and would be the responsibility of any GM with his salt to just laugh at and move on.

[StoicLeaf]

4) Why not? It works almost exactly like the Hydrogen cell of a Zeppelin.

I'm not adamant about it being RAW, only adamant about it not being contradicted by RAW, and reasonably allowed by inference.

Because hydrogen isn't magic, it's obeying physics.
tenser's disc does not have the ability to move obstacles.

look, you want RAW to contradict your plan?
here. DMG page 5.
There are way too many blanks in your setup, a DM would need to arbitrate, you've been told by numerous people they wouldn't allow this in their game.
Debating the technicalities of it seems pointless at this point because you refuse to see things from anyone else's perspective.

[Hrugner]

If the flag hangs from the chair on the disc thing, it's supported by the disc, not by air. It's essentialy the same as the bottom side of the proposed shell case, only somewhat lighter and less durable.

Except the metal shellcase will tend to fall despite the wind whereas the flag will rise due to it.

[JackPhoenix]

Except the metal shellcase will tend to fall despite the wind whereas the flag will rise due to it.

Not true. A flag that big is quite heavy, you'd need pretty strong... and most importantly constant... wind to make it rise. And then it will still be hanging from the device, not fly on its own... if it's un-fastened, strong enough wind will just blow it away. Not to mention I don't think anyone would consider a flag "ground".

[ebbisis]

My own personal ruling on this if I was DM would be the disk exerts a equal force downwards as it pushes upwards. This would mean that the disk and shell would remain earthbound. It would be interesting if the disk would release the potential energy like a spring due to being lower than its normal height or the disk would simply disappear due to not reaching its operational perimeters or even automatically align its new ground reference to the top plate.

I like the idea of tensor's spring , line up a few and you could propel a rail based land vehicle, about 500 together and you can launch space craft ,just remember to cast tiny hut or expect a few hundred bludgeon damage from inertia.

[Renduaz]

They aren't supported by the disc which is apparently a problem for some people. If we're ruling you could put one in the basket of a hot air balloon, then clearly we could put one on something else that maintains elevation due to air pressure. hanging a flag from the chair at the front of your disc would give you a surface supported by something other than the disk itself that would also provide a path up to the pilot of the craft which is also apparently necessary.

Well, anyway, I actually just edited my post to illustrate to the poster I was talking with why you don't actually need a path all the way up to the pilot of the craft.


Because hydrogen isn't magic, it's obeying physics.
tenser's disc does not have the ability to move obstacles.

look, you want RAW to contradict your plan?
here. DMG page 5.
There are way too many blanks in your setup, a DM would need to arbitrate, you've been told by numerous people they wouldn't allow this in their game.
Debating the technicalities of it seems pointless at this point because you refuse to see things from anyone else's perspective.

Except it's not moving an obstacle in this design, it's moving an object that it carries on top of itself, which it does have the ability to. What about DMG page 5? I've actually acknowledged several arguments from a few posters and either changed the device's technique to overcome them, or told them they would have to make a ruling on the matter.


My own personal ruling on this if I was DM would be the disk exerts a equal force downwards as it pushes upwards. This would mean that the disk and shell would remain earthbound. It would be interesting if the disk would release the potential energy like a spring due to being lower than its normal height or the disk would simply disappear due to not reaching its operational perimeters or even automatically align its new ground reference to the top plate.

I like the idea of tensor's spring , line up a few and you could propel a rail based land vehicle, about 500 together and you can launch space craft ,just remember to cast tiny hut or expect a few hundred bludgeon damage from inertia.

How can the disk exert an equal force downward if it hovers above the ground?

[Kornaki]

How can the disk exert an equal force downward if it hovers above the ground?

The disk lives equally in the Material and the Ethereal levels of reality. While many people know the Ethereal plane is a shadow of the Material plane, what they don't realize is that due to eons of slight dissimilarities in the events that play out on the two planes - there is no wind on the ethereal plane, for example, the radius of the planet on the ethereal plane is actually three feet higher than it is on the material plane. When people shift between planes they are seamlessly transported these three feet up or down, but the Disk reveals the truth in its bizarre hovering capabilities.

[Renduaz]

The disk lives equally in the Material and the Ethereal levels of reality. While many people know the Ethereal plane is a shadow of the Material plane, what they don't realize is that due to eons of slight dissimilarities in the events that play out on the two planes - there is no wind on the ethereal plane, for example, the radius of the planet on the ethereal plane is actually three feet higher than it is on the material plane. When people shift between planes they are seamlessly transported these three feet up or down, but the Disk reveals the truth in its bizarre hovering capabilities.

Is that actually found in some book or homemade lore? Either way, interesting idea.

[Kornaki]

Is that actually found in some book or homemade lore? Either way, interesting idea.

I'm glad you like it, thanks. It's something I just made up for my own games.

[MeeposFire]

I honestly do not think outside of this conversation that most people would argue that you could not use the floating disk while on an air ship, a boat, or probably even a giant eagle a mile long in wing span that you are riding (such as in Golden Axe).

What seems to be the problem with some here when you boil it down to its roots is a question of size (an air ship is big and a board is potentially small) or that the floor is self supporting in the air itself (air ship floats on its own but the board would not without the contraption potentially).

So the question becomes in your definition of ground if you think this does not work for one or both of those reasons how does the definition work that gives us the details on how big it has to be or that it has to be self flying in order to be ground?

[Renduaz]

I honestly do not think outside of this conversation that most people would argue that you could not use the floating disk while on an air ship, a boat, or probably even a giant eagle a mile long in wing span that you are riding (such as in Golden Axe).

What seems to be the problem with some here when you boil it down to its roots is a question of size (an air ship is big and a board is potentially small) or that the floor is self supporting in the air itself (air ship floats on its own but the board would not without the contraption potentially).

So the question becomes in your definition of ground if you think this does not work for one or both of those reasons how does the definition work that gives us the details on how big it has to be or that it has to be self flying in order to be ground?

We know how big it has to be from the spell description which mentions Tenser's Disk will climb up stairs. From that we know that a stair is big enough for Tenser's Disk to consider ground so that it floats 3' above it, and changing it's ground reference as soon as it moves to the next stair. The self-flying aspect isn't covered anywhere. But you could argue that if a metallic sheet was ruled to be ground while you cast Tenser's Disk on it, then it will always be a ground, and can't really stop being ground once it's in the air, since Tenser's Disk already uses it as a ground reference from the beginning.

[sir_argo]

I honestly do not think outside of this conversation that most people would argue that you could not use the floating disk while on an air ship, a boat, or probably even a giant eagle a mile long in wing span that you are riding (such as in Golden Axe).

What seems to be the problem with some here when you boil it down to its roots is a question of size (an air ship is big and a board is potentially small) or that the floor is self supporting in the air itself (air ship floats on its own but the board would not without the contraption potentially).

So the question becomes in your definition of ground if you think this does not work for one or both of those reasons how does the definition work that gives us the details on how big it has to be or that it has to be self flying in order to be ground?

I don't think it's the size that makes it "ground". To me, it is ground if it is supported. Key in on the word support. If what is below the TFD is not supported, it isn't considered ground.

I am standing on Joe's shoulders. Joe is standing on a ladder. The ladder is on a cart. The cart is on the ground. I can trace a path of support to something that provides all of the above with support. If I cast a wall of force in mid-air, it can provide support to the ladder, which would support Joe, who supports me. I can trace support to the wall of force.

But I would argue that it can't trace back to itself. I am standing on Joe's shoulders, who is standing on a ladder, which is standing in a basket, that is suspended from a rope that I am holding. The support traces back to itself. In this situation, there is no "support" and the whole contraption will fall.

As for the Tenser's Floating Disk, I believe it should follow that same rule. If the support traces back to itself (the TFD), it will "fall" until it is 3' above something that does have support.


The size of the support wouldn't matter. It could be a tightrope and it would work. But that tightrope has to be anchored to something that provides true support.

[Renduaz]

I don't think it's the size that makes it "ground". To me, it is ground if it is supported. Key in on the word support. If what is below the TFD is not supported, it isn't considered ground.

I am standing on Joe's shoulders. Joe is standing on a ladder. The ladder is on a cart. The cart is on the ground. I can trace a path of support to something that provides all of the above with support. If I cast a wall of force in mid-air, it can provide support to the ladder, which would support Joe, who supports me. I can trace support to the wall of force.

But I would argue that it can't trace back to itself. I am standing on Joe's shoulders, who is standing on a ladder, which is standing in a basket, that is suspended from a rope that I am holding. The support traces back to itself. In this situation, there is no "support" and the whole contraption will fall.

As for the Tenser's Floating Disk, I believe it should follow that same rule. If the support traces back to itself (the TFD), it will "fall" until it is 3' above something that does have support.


The size of the support wouldn't matter. It could be a tightrope and it would work. But that tightrope has to be anchored to something that provides true support.

It will fall because your bakset doesn't have any innate floating magic or a "follow character in any direction" magical property. Your analogy would be comparable to the TFD contraption only if for example, it was more than 20' feet tall, and your basket had a magical clause that it always hovers 3' feet above a rope and that it will attempt to follow you in any direction if you get away. So in that case it will rise, not fall.

As I said many times before, the principle which lifts TFD's in my design is actually found in real life physics. All you have to do is think of TFD, a plane of force, as the hot air in a hot air balloon. You put a pocket ( A concentration of matter in gas form ) of hot air between a basket and a balloon with a burner to keep it rising, and that force pushes up something that is on top of it, which lifts up the basket below it, which also lifts up the burner, achieving a circular effect. TFD is the hot air, the upper shell casing is it's balloon placed on top of it, and the lower casing which it needs as a ground reference is it's basket. The player sitting 20+ feet away in a 130 degree angle is the burner which keeps TFD rising, but using a magical property of the disk instead of heat. That's all there is to it.

[sir_argo]

It will fall because your bakset doesn't have any innate floating magic or a "follow character in any direction" magical property. Your analogy would be comparable to the TFD contraption only if for example, it was more than 20' feet tall, and your basket had a magical clause that it always hovers 3' feet above a rope and that it will attempt to follow you in any direction if you get away. So in that case it will rise, not fall.

As I said many times before, the principle which lifts TFD's in my design is actually found in real life physics. All you have to do is think of TFD, a plane of force, as the hot air in a hot air balloon. You put a pocket ( A concentration of matter in gas form ) of hot air between a basket and a balloon with a burner to keep it rising, and that force pushes up something that is on top of it, which lifts up the basket below it, which also lifts up the burner, achieving a circular effect. TFD is the hot air, the upper shell casing is it's balloon placed on top of it, and the lower casing which it needs as a ground reference is it's basket. The player sitting 20+ feet away in a 130 degree angle is the burner which keeps TFD rising, but using a magical property of the disk instead of heat. That's all there is to it.

But a TFD doesn't provide unsupported lift. It will only float 3' above something else that does provide support. In reference to your example, a hot air balloon will float by itself. A TFD won't. So the two are not analogous.

Your TFD is floating down. What have you got underneath it that will stop its fall? If it is something attached to the TFD, that is also falling.

[Renduaz]

But a TFD doesn't provide unsupported lift. It will only float 3' above something else that does provide support. In reference to your example, a hot air balloon will float by itself. A TFD won't. So the two are not analogous.

Your TFD is floating down. What have you got underneath it that will stop its fall? If it is something attached to the TFD, that is also falling.

You haven't really phrased it clearly here, but I understand that your argument is that you'll only consider something "ground" in relation to TFD if it's supported by something other than TFD itself. Also in my example, TFD isn't analogous to the hot air balloon, it's analogous to hot air, it's the basket and balloon which won't float by themselves, and they are analogous to the shell. the only difference is that hot air keeps rising, but TFD stops at 3'. But it will also follow the player at any direction up to 10' from it's ground, so you can exploit that to make the disk keep rising by using "carrot in front of horse" kind of trick. You could say that hot air doesn't require support, but it actually does, by the denser cold air.

Also, TFD doesn't float down, unless it needs to do so in order to follow you. TFD is unaffected by gravity, or else it wouldn't levitate. TFD is only affected by it's own magical laws.

So the only question here is whether or not TFD can be defined as carrying it's own ground. You could argue that it is supported, by the disk's magic. If the disk has a magical property of moving up and forward to follow a player while ignoring gravity, then the ground is being supported by that magic. Granted though, that would require you to define ground in the first place. So it's a DM ruling more than it is a logical flaw as you seem to think.

Let me explain it to you step by step. Let's say I put my metal shell down on the actual earth ground, and cast TFD on it. So far, it's perfectly fine "ground" to you, because the metal shell is sitting on the actual earth's ground, correct? Now, the spell description also tells us that TFD will rise up to 10' from it's ground to match an elevation change in the player's location. so if I get 20' away and 8' up, it's gonna levitate some more while going forward to reach me, yes? Well according to you, the moment that our lower metallic plate leaves the actual earth, it stops being ground. But the disk must also attempt to rise 10' above it's ground to match a player's elevation change first. So with you as DM, what would the disk do? Start rising above it's "ground" ( the shell ) for like an instantaneous moment, thus lifting that "ground" from the earth, and then realizing it's no longer ground since it isn't supported? And then float back down? Except TFD never floats down when the player is above it. That's right in the spell description. It has no such attribute as floating down for any reason other than to follow the player down. So you'd have to invent a new rule or break the spell mechanics.

[sir_argo]

Whoa... I'm not understanding that, but I'll try my best



So with you as DM, what would the disk do? Start rising above it's "ground" ( the shell ) for like an instantaneous moment, thus lifting that "ground" from the earth, and then realizing it's no longer ground since it isn't supported? And then float back down?

In real physics, you cannot lift yourself. Stand on a cinder block. reach down and try to lift the cinder block. It won't work.

Tenser's Floating Disk is effected by gravity. It has the ability to float up for changes in elevation, but other than that, it sinks down to a level 3' above ground level. If you want, picture the disk as a 5' round table with 3' long legs, but can extend those legs up to 10' in order to change elevation, but it will always pull back to 3' afterwards. When the caster climbs an 8' wall the disk extends it's legs to rise up to the top of the wall and effectively climbs up. These imaginary legs cannot "push" against a metal shell that is attached to the TFD any more than you could lift the cinder block under your feet.

Now, just to be clear, what you are saying and what I am saying are not RAW. The spell isn't clear on this issue. I don't think anyone can claim RAW on this. Everybody will read the spell and come up with a different conclusion. We differ on what we consider "ground". I don't think anything attached to the disk counts; you do. I don't know where we go from here.

[McNinja]

I don't know where we go from here.
Nowhere.

He goes away because tensers floating disc obviously sees the "ground" as the immediate surface it is cast on.

You go away because the disc obviously sees the "ground" as "obviously the ****ing ground not some 4 foot circle of dirt suspended in mid-air paradoxically."

Then the thread ends and we all gtfo because as long as Renduaz keeps attempting to Rules Lawyer the meaning of the word "ground" this thread will keep going in circles just like it has for the last 5 pages.

EDIT: And yes, Renduaz, I do understand exactly what you're saying, but the spell specifies the ground, as in "the solid surface of the earth" as in you're in a forest and you're walking on the damn ground. That's why it specifies that you can go up stairs but it can't float over a 10 foot deep pit. Once you carve a chunk out of the earth, it is no longer the ground, it's a floating piece of earth. We all understand that you desperately want this to be a totally legit method of flying at level 1, but normal human logic dictates that it doesn't work.

[Renduaz]

Whoa... I'm not understanding that, but I'll try my best




In real physics, you cannot lift yourself. Stand on a cinder block. reach down and try to lift the cinder block. It won't work.

Tenser's Floating Disk is effected by gravity. It has the ability to float up for changes in elevation, but other than that, it sinks down to a level 3' above ground level. If you want, picture the disk as a 5' round table with 3' long legs, but can extend those legs up to 10' in order to change elevation, but it will always pull back to 3' afterwards. When the caster climbs an 8' wall the disk extends it's legs to rise up to the top of the wall and effectively climbs up. These imaginary legs cannot "push" against a metal shell that is attached to the TFD any more than you could lift the cinder block under your feet.

Now, just to be clear, what you are saying and what I am saying are not RAW. The spell isn't clear on this issue. I don't think anyone can claim RAW on this. Everybody will read the spell and come up with a different conclusion. We differ on what we consider "ground". I don't think anything attached to the disk counts; you do. I don't know where we go from here.

I get it. I'd accept your ruling, and I think you're right about neither of it being addressed in RAW. Having said that, I think I can explain how my side could be a possible rule interpretation. First of all, those cinder blocks and other analogies aren't really accurate, since all of those objects act in accordance with the laws of physics such as gravity, they don't have any innate laws of their own about their position like TFD does. Secondly, TFD has a magical ability to follow players on it's own whenever they're 20 feet away, which doesn't happen in real physics. Newtons' First Law.

TFD is most definitely not affected by gravity. If I put a disk which wasn't magical 3' above ground it will fall down, not levitate in place. Now, you want me to picture it has having 3' long legs. But we know that in reality, when you cast TFD, you cast nothing save for the 3' diameter, 1 inch thick plane of force. There is absolutely nothing else changed about reality except for that. There aren't any invisible legs made out of force beneath the disk or anything else to actually support it. There's nothing but air 3' underneath it. If we wanted to theorize, we could say the air serves as it's support, but that would be wrong for a number of reasons, not the least of which is that the spell description says nothing about that, and the disk wouldn't fall if you created a momentary vacuum beneath it.

The only law that TFD answers to is that of The Weave, being a magical plane of force that obeys certain magical rules. I know that you want me to think of those rules as some kind of special gravitational pull that TFD abides by, but the fact that this is just a mental image and not reality changes everything. It's not affected by gravity, it doesn't actually have legs keeping it physically attached to the ground. A real table would need legs, otherwise it'd fall down because of gravity. TFD doesn't need anything physically attaching it to the ground, it's magic only needs to be 3'-10' above it. You can imagine it as an attachment to make an equivalence with gravity, but it's not really attached since it's magic, not gravity, and that matters more than you know.

Let's use your extending table to demonstrate the difference. I have a table 3' feet above the earth or a floor, standing on 3' legs which somehow extend up to 10'. I put that table on a metal plate, then I put a metal plate on the table, and I attach the upper metal plate to the lower one with chains. I then try to extend the legs. Do you know what happens? Nothing. The legs try extending up, making the table push against the upper metal plate while at the same time the legs are exerting an equal amount of pressure on the lower plate as they try to lift the burden, never moving until they even eventually break if enough equal pressure is exerted. It's the same thing as putting a coiled spring in a box. Because that's how gravity and the laws of motion work.

Now let's replace our table with TFD. Unlike round table which is suspended 3' in the air by means of a power called "Gravity", and for that purpose it must also actually have 3' legs below it, being pulled down by gravity to the ground from whence they can no longer be pulled down, and therefore keeping the table up, TFD is suspended 3' above the ground by a power called "Magic". It doesn't need any other object pushing it upward by force of gravity. So let's imagine in our previous thought experiment that we just made the legs vanish from our table, and instead of falling down since nothing is pushing it up away from the gravitational pull, it just defies that law of physics with it's own law of magic and stays in place. Recall that our physical table was motionless because as soon as it's legs tried extending up to lift the metal plate attached to the metal plate they stand on, they exerted equal pressure on both plates. Now there is absolutely nothing on the lower plate, only our magically hovering table pressing against the upper plate. ( You could try to rule that TFD has an invisible force which behaves like gravity by pushing down on the ground beneath it relative to the amount of weight placed on the disk, so for example if the disk is carrying 100 pounds of loot and a person was crawling beneath it, he immediately be flattened to the ground by a force of 100PSI, but the spell description doesn't state that, because the disk doesn't work according to the laws of physics ). So when the disk now starts lifting what's on top of it, extending it's non-existent legs which don't actually exert pressure on the ground, there is in fact nothing stopping that lower plate from rising along with the upper plate it's attached to.

Or in the simplest terms possible - Your table has nothing beneath it, instead it has an omnipresent hand which has only one instruction - "Keep TFD 3' above the ground and pull it up to 10' from it to follow some guy". That hand is the magic. It can be anywhere it wants to. It's currently grabbing the table 3' off the ground. Player climbed 8' wall? Omnipresent hand pulls the table 8' up in the air. Elevation change of more than 10'? Hand refuses to do anything.

Physics isn't the problem here, it's how we define ground. There's in fact an easy way to settle this. Is "Falling ground" still a ground? If a party is on a cliff face which is slow descending down the sky, or a sinking airship, can they cast grease on them for instance? If so, then ground which isn't supported by it's own right, and therefore in the process of crashing down to another ground by the pull of gravity, would still be ground. So if I put my Tenser's disk and it's shell on a cinder block, go sit on the heightened chair in my contraption, and then have someone kick the cinder block from down under it, The shell, which is affected by gravity, will attempt to fall down. TFD, which is magically suspended in any place as long as it's 3' above it's ground, if it does still consider the falling lower casing to be ground, would've simply locked in place 3' above, but you could still argue that the lower case as ground instantly tries falling down, and TFD immediately follows it to maintain 3', and the upper casing on top of it also falls down along with the disk, thus the whole shell and the disk are falling down.

And that's where TFD's magical quality of rising up to 10' in order to reach a player comes in. Because I'm in the angled chair in an elevation above the disk and 20' away from it, it doesn't just stay 3' in place above it's falling ground ( The lower casing ), But attempts to rise up. So as the cinder block is kicked from under the lower shell, it starts falling, but TFD doesn't follow it, because it can still maintain an elevation change of 7' more to match the player in the chair, so instead it levitates up, moving the upper casing up, which also pulls the lower casing up, making it stop falling and rising up along with the disk instead.

Imagine you have a 100' tower, with a balcony jutting out from the top and stretching 20' feet forward, which somehow weights less than 500 pounds. TFD is cast on it at the very edge, the player puts something on top of the disk, and attaches it to the balcony rails with chains on all sides. The player then goes to the balcony's entrance, still something like 19 feet away from the disk. The disk remains immobile. The balcony is dislodged and begins to crash, the player quickly steps into the tower before it does, moving more than 20 feet away from the disk. If you consider the balcony to still be ground while it's falling, then TFD by virtue of levitating 3' above it, falls down along with it, always 3' above the falling ground. It tries to move like 1 feet forward towards the player, pulling the balcony forward by the rails with it, so that it is within 20 feet range of the player standing at the entrance. But then after falling down about 20 feet vertically, it needs to move up from it's ground to reach the player. So instead of hovering 3' above the falling balcony, it now starts rising up It can keep doing so until it's 10' over the balcony. As soon as it does, it also pulls up the object which the player placed on it, pulling up the chains attached to the balcony rails, and the balcony jerks in mid-air into an halt, starting to rise as it's pulled by the chains up, which are pulled by the object on the disk up, which is pulled up by the disk, which is pulled up by the omnipresent hand that we call magic whose only rule is "I'll keep you 3' above ground or let you fly up to 10' from it if the player is above you and more than 20 feet away"

That's why the device works as long as you still consider a ground which is falling to be ground. And common sense would actually dictate that it is. If I'm on a falling airplane, can I still put things down or spill stuff on the hallway ground? Yes, they will just fall with the plane. Could I cast "Grease" on a vertically falling platform? Yes. And the best part of all? It's not even "unsupported". It's actually lowered ground. You can in fact trace support for it all the way down to the earth's gravitational pull ( I.E the earth ground ). It's called air resistance. In fact, if you want to talk about real world physics, you don't even need air resistance, the earth's gravity itself is what "supports" everything. What's the actual soil and the magma it moves upon supported by? The center of gravity at the earth's core. The lack of gravity in empty interstellar space is the "default" unsupported plane of the universe.

The air and earth's gravity are like a rotary lift pulling you down extremely fast. So if you're on a crashing airplane, it is being supported, first by the air resistance ( Which simply isn't enough to slow down the speed at which you're going down ), and then by a center of gravity which is pulling you down towards it very fast. Not being supported means you'd just hang in place motionless as if you were in space and so will everything else. In which case you actually couldn't make the airplane ground "support" any object or liquid, if you put them above it, they'll just stay motionless as if on a space station. If you pushed them down, they'll hit the floor, then bounce back up. You could put something on the ground by placing it there directly, but it wouldn't actually be "supported". It would just be suspended as close as possible. That's what it means to be unsupported by anything.

Therefore real world physics and logic ( Such as being able to cast grease on a falling cliff face ) would dictate that falling ground is still ground. And if it is, Tenser's Skystrider still works.


Nowhere.

He goes away because tensers floating disc obviously sees the "ground" as the immediate surface it is cast on.

You go away because the disc obviously sees the "ground" as "obviously the ****ing ground not some 4 foot circle of dirt suspended in mid-air paradoxically."

Then the thread ends and we all gtfo because as long as Renduaz keeps attempting to Rules Lawyer the meaning of the word "ground" this thread will keep going in circles just like it has for the last 5 pages.

EDIT: And yes, Renduaz, I do understand exactly what you're saying, but the spell specifies the ground, as in "the solid surface of the earth" as in you're in a forest and you're walking on the damn ground. That's why it specifies that you can go up stairs but it can't float over a 10 foot deep pit. Once you carve a chunk out of the earth, it is no longer the ground, it's a floating piece of earth. We all understand that you desperately want this to be a totally legit method of flying at level 1, but normal human logic dictates that it doesn't work.

That's not even his argument. Saying "the ground is the solid surface of the earth" is nonsense, that means you can't cast any ground spells in dungeons or house floors. His argument is that the ground must be supported by something. and I just wrote a lengthy explanation of why even that won't stop TFD from working. And the spell never specifies that the ground is "the solid surface of the earth". Ground is only ever specified in previous editions where it says "Anything you can line prone upon, fight upon, or leave tracks on". And the reason it can't float over a 10 foot deep pit is because that requires it to change a 10 feet elevation from the ground it's currently on. And if you take a chunk of earth like a rockbed and fling it up, it's a "falling ground", no not because it came from the earth's soil, that's irrelevant and completely false, or otherwise I wouldn't be able to cast Grease in a dungeon. It's because it's a surface that you could put something on. And the reason why is because it's actually being supported. By gravity itself, which is just pulling it closer to it's center.

[McNinja]

That's not even his argument. Saying "the ground is the solid surface of the earth" is nonsense, that means you can't cast any ground spells in dungeons or house floors. His argument is that the ground must be supported by something. and I just wrote a lengthy explanation of why even that won't stop TFD from working. And the spell never specifies that the ground is "the solid surface of the earth". Ground is only ever specified in previous editions where it says "Anything you can line prone upon, fight upon, or leave tracks on". And the reason it can't float over a 10 foot deep pit is because that requires it to change a 10 feet elevation from the ground it's currently on. And if you take a chunk of earth like a rockbed and fling it up, it's a "falling ground", no not because it came from the earth's soil, that's irrelevant and completely false, or otherwise I wouldn't be able to cast Grease in a dungeon. It's because it's a surface that you could put something on. And the reason why is because it's actually being supported. By gravity itself, which is just pulling it closer to it's center.
The spell doesn't have to specify what the ground is. The definition of "ground" is "solid surface of the earth." And no, if the ground is falling its because gravity is pulling it down. The same way gravity would pull a chunk of earth down and TFD would come down with it, and some dip**** wizard about a second later.

[Mhl7]

Note to self: Homebrew definition of ground: Anything that weights more than 500 pounds.

The idea with the 6 immovable rods seems way more reliable, RAW and RAI.

[Renduaz]

The spell doesn't have to specify what the ground is. The definition of "ground" is "solid surface of the earth." And no, if the ground is falling its because gravity is pulling it down. The same way gravity would pull a chunk of earth down and TFD would come down with it, and some dip**** wizard about a second later.

So you don't let your players cast Grease or TFD in towers, dungeons, city pavements or flying platforms? And yes, the ground is falling because gravity is pulling it down. And TFD would come down with it ( While staying 3' above it in the air ). Unless there was some kind of magic pull making TFD try to fly above that up to 10', in which case if you put something on TFD and tied that thing to the falling chunk of earth, TFD would rise up via it's gravity overriding magic, the thing you put on it will rise up, and the chunk of earth would stop falling, since it's now being carried by a magical force that ignores gravity. That's how the device works.


Note to self: Homebrew definition of ground: Anything that weights more than 500 pounds.

The idea with the 6 immovable rods seems way more reliable, RAW and RAI.

What's the idea? I haven't heard of it. Regardless, there are magic Items like the flying broom or the flying carpet which simply let you fly on them as their RAI. But it's up to your DM to decide when, where, and how many immovable rods you can get, since they're uncommon magical items. They're probably not being sold like iron beams, or else everyone in the world would be using them or building with them instead of doing so ordinarily. If your DM does let you buy them somewhere, then they also cost a lot. Tenser's Skystrider utility is in it's availability mostly. Actually wait, I remember the 6 immovable rods, I'll comment on it soon.

And yes, an homebrew definition like that would render the design obsolete.

[N810]

Note to self: Homebrew definition of ground: Anything that weights more than 500 pounds.

The idea with the 6 immovable rods seems way more reliable, RAW and RAI.

Thanks man :D

[Mhl7]

looks like I need 6 if I am going to be able to turn...



https://scontent-sjc2-1.xx.fbcdn.net/v/t1.0-9/fr/cp0/e15/q65/17757446_10155208072791096_5763463331835059822_n.j pg?efg=eyJpIjoiYiJ9&oh=30720155fe061db141c9e0aa3cbd1add&oe=596732A8

The big pyramid is a suspended platform.

The basic idea is a automatic immoveable rod ladder.
so it's going to take a little muscle power.
the red circles are rods that are off, the blue circles are on,
the squares turn the rods on and off.
the 2 yellow objects are fixed rods on ball bearings,
to change directions. you have to stop and activate one of those
and then hit the big button to turn of the tracked rods,
the manually swivel the devise, turn the rods back on the pivot rod off again
and them go in your new direction.

This one! (I thought it needed a repost after 4 pages)

More on topic: I find the poster idea perfectly fine from a strict RAW point of view, and I would totally allow it with the right role play (like from some artificer or inventor wizard of some kind), but maybe not at level 1.

However, I think it is not RAI at all! Also, as others have point out, there might be some physical problem, but since it is based on a magically floating disc, I would not be lingering too much on that.

If this adventure let the player grab an airship sustained by a fire elemental I don't see any problem building one based off a TFD

Also, the idea of a portal to the elemental plane of air which imports hellion to sustain an airship has at least two problem in my view: 1-how do you pick exactly hellion and not other heavier materials? 2-how do you make the portal follow the ship (I guess that a lot of people defining the ground as immovable here on this thread would never allow a portal following the ship).

Still, it is a cool idea and i would roll with it.

[Renduaz]

Thanks man :D

Your design looks very complex, but I can't really comprehend how it functions. First of all I don't realize what's the red rectangle with the blue filling, nor the yellow rectangle in the middle with a tiny red button in the middle. Secondly, I don't understand how the "buttons" work. Something has to manually press the button on one end of a rod to turn it on or off, you don't have some kind of modern electricity for that ( And your character probably wouldn't be able to create circuits by his own on DND ). So I don't understand what those various buttons placed on assorted spots away from the rods even do.

The only thing I can conceive of is that you have the fixed yellow rod in the center, horizontal, wires attached on both ends to carry a surface attached to them ( the pyramid ), And then you have some kind of metal beams attached to the yellow rod vertically, with the gears and chains mechanism and 2 rods at intervals on each chain.

And now I don't understand either how your "squares" turn those rods on or off, nor which rods do you even want to turn on or off in order to move up or in any direction. Can you simplify? Could you point out on your diagram what each shape actually is and what you're turning on and off and how?

[N810]

Yea, it's more of a diagram than a blueprint,
the idea for the switches is that the yellow ones are manually operated
and only need be used then you want to change direction.

The red a and blue "switches" would just be little metal ramps that would push the button on the rod and they get cranked past.
the BIG switch would be some sort of lever or something that would turn off all the rods on the belt at once, mostly for convince,
as you could do this manually as well.

This devise as is needs muscle power to work, I suppose you could add a reduction gear for weaker characters or have 2 people operating the crank.
mechanically it's just a crude ladder climbing devise using 2 gears and a bicycle chain. The difference is with immoveable rods, you will never run out of ladder.

[Renduaz]

Yea, it's more of a diagram than a blueprint,
the idea for the switches is that the yellow ones are manually operated
and only need be used then you want to change direction.

The red a and blue "switches" would just be little metal ramps that would push the button on the rod and they get cranked past.
the BIG switch would be some sort of lever or something that would turn off all the rods on the belt at once, mostly for convince,
as you could do this manually as well.

This devise as is needs muscle power to work, I suppose you could add a reduction gear for weaker characters or have 2 people operating the crank.
mechanically it's just a crude ladder climbing devise using 2 gears and a bicycle chain. The difference is with immoveable rods, you will never run out of ladder.

Okay, then I'll ignore the yellow rods since I haven't even figured out how you would go up or down with that thing. I must confess I'm still not really sure how it goes up. Your diagram for example says that the blue rods are on ( immoveable ), and you wouldn't be able to pull the crank down like that, unless your intention is for a player to succeed a DC 30 strength check to pull them down? But the the ramp buttons, and the yellow rod holding it, and the whole thing, I'm actually very confused. I guess I'll wait for something more detailed if you ever post it.

[Ruslan]

A very nice 5-step plan, but I think the OP forgot:

6. Find a DM who would say yes to all of that.

[N810]

The yellow rods are normally off.
If that helps.

tuning the crank as shown pushes up the devise.
the switches turn off a rod so it can be recycled back to the top
where it is turned on again. Basically automating doing this manually.

here's the devise in horizontal mode.
https://scontent-sjc2-1.xx.fbcdn.net/v/t1.0-9/fr/cp0/e15/q65/17523043_10155216572261096_2734418020681691980_n.j pg?efg=eyJpIjoiYiJ9&oh=298fdb63400fea7ea74a978b9615ae3a&oe=5952BCAD

http://4.bp.blogspot.com/-DUkdBfpyWZU/Ur2gLHdJAXI/AAAAAAAACE8/puOvZPSPJRA/s1600/1334623289724.jpg

[Renduaz]

A very nice 5-step plan, but I think the OP forgot:

6. Find a DM who would say yes to all of that.

Thanks, I did include that step in the OP though - "Here are the instructions which should hopefully, if your DM doesn't shut this ploy down before you become the realm's Lenoardo Da Vinci"

[Renduaz]

The yellow rods are normally off.
If that helps.

tuning the crank as shown pushes up the devise.
the switches turn off a rod so it can be recycled back to the top
where it is turned on again. Basically automating doing this manually.

http://4.bp.blogspot.com/-DUkdBfpyWZU/Ur2gLHdJAXI/AAAAAAAACE8/puOvZPSPJRA/s1600/1334623289724.jpg

Alright then, let's just ignore the yellow rods and the buttons ( Assume player turns off your rods manually ).

You have a vertical metal beam, with a crank attached below, and a wheel attached above like a bicycle. The cranks are the pedals, and the wheel above moves when the wheel below is moved using the handles, right? Then you have some kind of wire entwined through both wheels with the rods where you put them. First of all, if the blue circles are on, when you turn your crank, the wire won't move, it will just futilely tug on the immoveable blue rods which are stuck where they are in space. Unless your intention is to make DC 30 strength check? ( Is it your intention? ). In which case, since they are the only things carrying the floating contraption ( They are the only rods which are turned on and not affected by gravity ), then you move them down with the wire, the whole thing moves down with them, then you maybe turn on the red ones, but they're only slight higher, but they're not really like a ladder, they're going in a circular motion because of your wheel, And what about the double strength 30 DC checks you'd have to make each time, and honestly I completely lost of track of everything. I'm giving up, I'd have to see a much better illustration to have a chance of understanding your intention.

I only understand the manual ladder in the image. Except he'd have bend down very much to pick up the bottom rod each time he does that, possibly requiring a dexterity check.

[N810]

Why would you consider lifting yourself + about 40 pounds a DC 30 check ?

Also you could always add a reduction gear and a ratchet.
then even a wizard could manage.

I would imagine this more of a devise for overcoming obstacles than a regular means of transport.
unless of course you automate the hand crank.

[Renduaz]

Why would you consider lifting yourself + about 40 pounds a DC 30 check ?

Also you could always add a reduction gear and a ratchet.
then even a wizard could manage.

I would imagine this more of a devise for overcoming obstacles than a regular means of transport.
unless of course you automate the hand crank.

The blue rods are turned on in your diagram. Which means they are immovable ( even defying gravity ). They are attached to the wire running through your gears. When you pull your crank down, you're trying to move a wire which is attached to an active immovable rod, and the spell description says that you can only move an immoveable rod which is turned on by making a DC 30 strength check. Other than that, I'm not even sure how that thing is supposed to rise up in the air.

[N810]

You are not moving active rods, you are pushing your self up.

[Renduaz]

You are not moving active rods, you are pushing your self up.

Then what does your crank even do? Is it not attached to a wire which is attached to immoveable rods? Haven't you said that someone "pushes himself up" ( Somehow, I still have no idea how ) by pulling on the crank? Frankly I don't think either of us are ever going to get to the bottom of it until you provide better instructions

1. Show step by step what parts someone constructs to build the device, and where they're all connected to each other and in what manner

2. Assign identification to every shape or representation in the painting

3. Show where a character stands or whatever it is in your contraption

4. Have a step by step guide of exactly what is the character supposed to do, every step of the way, in order to simply make the device fly up vertically in the air

Right now I don't know anything about what you're envisioning when you ask for a character to "push himself" up on that thing.

[tieren]

This is fun, but doesn't work, and not for the reasons people keep arguing about.

Yes, the sheet below the disk is "ground." The argument here is clear and well thought out, and I'm sorry to the other posters claiming otherwise, but it simply makes too much sense to dispense with.

The problem is, your cyclical logic as to why the disc holds up the ground is flawed, because cyclical.

If you cast this, say, in midair, the disk would appear, would remain 3ft above the "ground" plate and support the plate above just fine, and the entire system would fall to the ACTUAL ground. When it hit the ground, my intuition is that the disc would still be there, still supporting the upper plate.

Imagine, if you will, a "ground plate" with a 3ft long steel pole jutting up from its center, and on top of that pole, you place another metal plate. You then connect the top plate to the bottom plate via some mechanism, complex or simple. Because the top of the pole can never be more than 3ft from the "ground plate", it will support the top plate, which will support the bottom plate, and you can fly.

And there's the problem. Tensors floating disc hovers relative to the ground, and that ground can also move. And it will. Downward. And so the disc will fall, and never as it falls will the spells rules be broken.

The example of an airship or hot air balloon should make this clear to everyone. If the ship descends while a tensor's floating disc is on deck, so does the disk. If you wrap a rope around the top of the disc and tie it to the ship, does the spell end because the ship weighs more than 500 pounds? Of course not. Only if the rope does. And if you move more than 20ft from it while it's tied down this way, it simply can't move if the rope is trapping it. And if the ship falls from the sky, the disc will remain, not holding up the ship, but still holding up it's rope (3ft above the ship) during the descent.

This is the correct answer.

it really doesn't matter if the disc can carry its own ground. If the ground it is carrying isn't supported it will go down because of gravity and the TFD will go down with it staying 3 feet above it.

OP uses examples of giants or treants lifting his portable ground reference and notes correctly the disc would move up with the lifting. He fails to note though that the same is true in reverse, as the bottom disc is lowered the TFD will fall; it can stay 3 feet above the "ground" as they fall together without breaking any of the spell descriptors.

[N810]

I get the feeling that if I provided a fully animated 3d rendering of the devise with the included physics...
You still wouldn't get it... as I am getting Trolled.

[Renduaz]

I get the feeling that if I provided a fully animated 3d rendering of the devise with the included physics...
You still wouldn't get it... as I am getting Trolled.

No, I really don't understand how someone pushes himself up with that thing, or how the rods interact with it, or how things are connected to each other. I'd like to see a step by step guide.


This is the correct answer.

it really doesn't matter if the disc can carry its own ground. If the ground it is carrying isn't supported it will go down because of gravity and the TFD will go down with it staying 3 feet above it.

OP uses examples of giants or treants lifting his portable ground reference and notes correctly the disc would move up with the lifting. He fails to note though that the same is true in reverse, as the bottom disc is lowered the TFD will fall; it can stay 3 feet above the "ground" as they fall together without breaking any of the spell descriptors.

That's not the correct answer. Read my last reply to sir_argo, I addressed the subject there, and even before that. Your mistake is forgetting what the disk does when someone is is more than 20' away from it and higher than it's ground, which is why my device needs a chair that can be pulled up by chain. You'll find the full explanation in my last reply to sir_argo.

[N810]

https://scontent-sjc2-1.xx.fbcdn.net/v/t1.0-9/fr/cp0/e15/q65/17523043_10155216572261096_2734418020681691980_n.j pg?efg=eyJpIjoiYiJ9&oh=298fdb63400fea7ea74a978b9615ae3a&oe=5952BCAD

WORKS LIKE THIS

https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcQn59nso4K2hwVrNvl9_hzdYA83qN8Fc kXwh0SUaMcNOIYCi3YhBA

ACTIVE IMMOVEABLE RODS = GROUND
both are immobile, notice how only the bottom part of the tank treads touch the ground, same thing.

[tieren]

And yes, the ground is falling because gravity is pulling it down. And TFD would come down with it ( While staying 3' above it in the air ). Unless there was some kind of magic pull making TFD try to fly above that up to 10', in which case if you put something on TFD and tied that thing to the falling chunk of earth, TFD would rise up via it's gravity overriding magic, the thing you put on it will rise up, and the chunk of earth would stop falling, since it's now being carried by a magical force that ignores gravity. That's how the device works.


This is your logical fallacy.

You are assuming that because the bottom plate can't move more than 3 feet from the top plate because they are connected that the entire system can't be lowered toward the ground by gravity.

You are taking too linear of a chain of thought, A can't move more than 3 feet from B, C must stay 3 feet above B, therefore A, B, and C can not move together by gravity towards the ground.

It is perfectly possible (and required) that they can all move together at the same time, even if none of them could move first on their own.

[tieren]

That's not the correct answer. Read my last reply to sir_argo, I addressed the subject there, and even before that. Your mistake is forgetting what the disk does when someone is is more than 20' away from it and higher than it's ground, which is why my device needs a chair that can be pulled up by chain. You'll find the full explanation in my last reply to sir_argo.

I read your response but it was not accurate. The disc won't move up to get to you, it seeks the best path along the ground, there is no path along the "ground" you are using so it will stop. At the same time gravity is working equally on you, your chair, the shell and every part of the system to accelerate them downward all at the same time. There is no part of the mechanic "stays 3 feet above ground" which will keep you all aloft.

[Renduaz]

https://scontent-sjc2-1.xx.fbcdn.net/v/t1.0-9/fr/cp0/e15/q65/17523043_10155216572261096_2734418020681691980_n.j pg?efg=eyJpIjoiYiJ9&oh=298fdb63400fea7ea74a978b9615ae3a&oe=5952BCAD

WORKS LIKE THIS

https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcQn59nso4K2hwVrNvl9_hzdYA83qN8Fc kXwh0SUaMcNOIYCi3YhBA

ACTIVE IMMOVEABLE RODS = GROUND
both are immobile, notice how only the bottom part of the tank treads touch the ground, same thing.

I asked for step by step instructions, and at the very, very least, an identification in text of each part, and where the players is supposed to stand on. You just flipped the image, so I still understand nothing. I have to struggle to figure out what you're thinking because you refuse to write down a step-by-step guide, to describe the components in your picture ( THIS IS GEAR, THIS IS METAL BEAM OF X LENGTH, THIS IS THAT, etc.. ), and the only thing I understand right now is that you perceive your active immovable rods as your "ground". So is your wire, AKA the tread, actually running on top of them, and they aren't attached to the wire? In that case, if it somehow moved like that, the thing would just slide off.

Look, dude. I really, REALLY don't know what your painting is meant to illustrate. And it's clear that you can't be bothered to provide a step-by-step guide or to give NAMES to all the different parts in the device, or to explain where exactly a player stands. So I'll just let other people understand it if they can and move on.

[N810]

............................ Go read the first post. :frown:

[Renduaz]

This is your logical fallacy.

You are assuming that because the bottom plate can't move more than 3 feet from the top plate because they are connected that the entire system can't be lowered toward the ground by gravity.

You are taking too linear of a chain of thought, A can't move more than 3 feet from B, C must stay 3 feet above B, therefore A, B, and C can not move together by gravity towards the ground.

It is perfectly possible (and required) that they can all move together at the same time, even if none of them could move first on their own.

No, I don't assume that. Now that you've read the response, let's discuss the actual logical fallacy that you have a problem with.


I read your response but it was not accurate. The disc won't move up to get to you, it seeks the best path along the ground, there is no path along the "ground" you are using so it will stop. At the same time gravity is working equally on you, your chair, the shell and every part of the system to accelerate them downward all at the same time. There is no part of the mechanic "stays 3 feet above ground" which will keep you all aloft.

This was the topic of my discussion with LordCdrMilitant, and I sent him a response to that too. It does have a path along with my "ground". In order to encapsulate the disk, the shell is larger in diameter than it. Say, 4' in diameter. The disk perceives that it still has 1' length of viable ground to traverse to get closer to the player, and does so. Only when it finishes, will it no longer have any further ground to traverse. Except it can never finish traversing that remaining 1', because as soon as it moves forward, it's ground moves forward with it. See my last reply to LordCdrMilitant on the topic.

"There is no part of the mechanic which will keep you all aloft" - Yes there is. The disk will rise up to 10' feet from it's ground while moving forward to match my elevation.


............................ Go read the first post. :frown:

Your first post seems incoherent to me when I look at your image. And you're not going to make a step-by-step guide of how you built the thing. ( I.E, I take a metal beam which is X and Y length, I nail a crank to it, etc ), there are also unknown components in your image, like the 2 rectangles, or the "wire" running through the wheels which, since you don't describe it neither in your picture or in your first post, I don't even know if it's actually a wire or tread or rope or anything about it, whether it's looped through a hole, or glued to something, or attached with nails. I don't know anything about your contraption from your post and image, so it can't make sense of it. Let's just assume it works and leave it at that.

[N810]

OK LET ME START OVER.

https://scontent-sjc2-1.xx.fbcdn.net/v/t1.0-9/fr/cp0/e15/q65/17760113_10155216784521096_3060238045022963624_n.j pg?efg=eyJpIjoiYiJ9&oh=9767e627a6b162c4854f7a150486209b&oe=5966E90A

[Ruslan]

Thanks, I did include that step in the OP though - "Here are the instructions which should hopefully, if your DM doesn't shut this ploy down before you become the realm's Lenoardo Da Vinci"So your instruction for step 6 is "hope". Yeah, that would have been my best suggested course of action as well :smallbiggrin:

[tieren]

No, I don't assume that. Now that you've read the response, let's discuss the actual logical fallacy that you have a problem with.



This was the topic of my discussion with LordCdrMilitant, and I sent him a response to that too. It does have a path along with my "ground". In order to encapsulate the disk, the shell is larger in diameter than it. Say, 4' in diameter. The disk perceives that it still has 1' length of viable ground to traverse to get closer to the player, and does so. Only when it finishes, will it no longer have any further ground to traverse. Except it can never finish traversing that remaining 1', because as soon as it moves forward, it's ground moves forward with it. See my last reply to LordCdrMilitant on the topic.

"There is no part of the mechanic which will keep you all aloft" - Yes there is. The disk will rise up to 10' feet from it's ground while moving forward to match my elevation.

You are inferring that. If the disc were following you along a floor and you reached a wall and climbed 20 feet vertically, there is nothing indicating that the disc would rise 10 feet and hand there unable to follow. The text seems to indicate it would settle back to 3 feet above the ground if unable to get to you.

The more significant problem is that you are still seeing your position above it in your chair as fixed in space and not falling to earth with the entire system.

Lets try the airship again. Lets say you cast TFD on the deck of an airship, and then you climb a rope 25 feet straight up to the balloon, the disc will stay on the deck. If the entire airship were to start a descent, you on the balloon and the disc on the deck would all descend together. The same thing is happening without the airship, there is nothign holding all of you up so the vehicle, the chair, you, and the disc all go down together.

[Renduaz]

OK LET ME START OVER.

https://scontent-sjc2-1.xx.fbcdn.net/v/t1.0-9/fr/cp0/e15/q65/17760113_10155216784521096_3060238045022963624_n.j pg?efg=eyJpIjoiYiJ9&oh=9767e627a6b162c4854f7a150486209b&oe=5966E90A

I apologize but that doesn't clarify anything to me. All I see is a tank with a bunch of immovable rods in it's treadmill, and since nothing is specified, for all I know they could be either inside the treadmill, or sticking out of it, and that it's treadmill would get stuck anyway because it's trying to move the active immovable rods. If anyone else is reading this, please tell me what N810 is trying to represent with that tank.

[tieren]

What I think would solve the problem for me would be if you had a mechanism to adjust the height between the ground plate and the top plate. Maybe a set of cables through a crank, tighten the crank and pull the plates together (say 2 feet 10 inches), disc will try to rise and may generate some lift to counteract the pull of gravity.

Problem will become weight pretty quickly. I wouldn't let you hang 20 feet off of one side without tipping the whole thing back towards the ground so you would need a counterweight off the back end to keep it stable and level. Unless you are a gnome or something I don't see it working out.

[Renduaz]

You are inferring that. If the disc were following you along a floor and you reached a wall and climbed 20 feet vertically, there is nothing indicating that the disc would rise 10 feet and hand there unable to follow. The text seems to indicate it would settle back to 3 feet above the ground if unable to get to you.

The more significant problem is that you are still seeing your position above it in your chair as fixed in space and not falling to earth with the entire system.

Lets try the airship again. Lets say you cast TFD on the deck of an airship, and then you climb a rope 25 feet straight up to the balloon, the disc will stay on the deck. If the entire airship were to start a descent, you on the balloon and the disc on the deck would all descend together. The same thing is happening without the airship, there is nothign holding all of you up so the vehicle, the chair, you, and the disc all go down together.

In your example I would be 20 feet vertically above the disk before it started following me, and since the disk can't change an altitude of over 10' from it's ground, then yes, it would remain 3' in place. In my contraption though, I'm 20' away horizontally from the disk ( And you'd have to get 100 feet away from the disk horizontally before the spell stops, by somehow hindering it with an obstacle ), but I'm only about 4'-6' or so above the lower shell casing in altitude, which is the disk's ground level.

And my chair won't fall to the earth because the entire system isn't falling to the earth, and the reason why is that the disk will push it up magically ( The disk doesn't give a **** about gravity ) in order to reach me, thus lifting the whole thing. You still don't really get it, probably because you haven't read all of my discussions.

In your airship example, the disk stays on deck because I'm at an altitude of more than 10' above it's ground altitude, which is the airship's floor. In my contraption I'm not more than 10' above the disk's ground in altitude. Only 4' or 6' above it. And your entire example is totally irrelevant because the disk isn't carrying it's own ground in the airship. Two completely different things in your example, dude. You gotta actually look at the contraption picture and then read all the responses in full.

By the way while we're talking could you help me understand N810's image with the tank or his ladder design? Because all I'm seeing is a tank whose treadmill will get stuck by trying to move active immovable rods.

[tieren]

In your example I would be 20 feet vertically above the disk before it started following me, and since the disk can't change an altitude of over 10' from it's ground, then yes, it would remain 3' in place. In my contraption though, I'm 20' away horizontally from the disk ( And you'd have to get 100 feet away from the disk horizontally before the spell stops, by somehow hindering it with an obstacle ), but I'm only about 4'-6' or so above the lower shell casing in altitude, which is the disk's ground level.

And my chair won't fall to the earth because the entire system isn't falling to the earth, and the reason why is that the disk will push it up magically ( The disk doesn't give a **** about gravity ) in order to reach me, thus lifting the whole thing. You still don't really get it, probably because you haven't read all of my discussions.

In your airship example, the disk stays on deck because I'm at an altitude of more than 10' above it's ground altitude, which is the airship's floor. In my contraption I'm not more than 10' above the disk's ground in altitude. Only 4' or 6' above it. And your entire example is totally irrelevant because the disk isn't carrying it's own ground in the airship. Two completely different things in your example, dude. You gotta actually look at the contraption picture and then read all the responses in full.

By the way while we're talking could you help me understand N810's image with the tank or his ladder design? Because all I'm seeing is a tank whose treadmill will get stuck by trying to move active immovable rods.

Picture the oval going around his drums as belts instead of wires and affix the rods to those belts.

As the crank is turned and the active rods can't move the belt will pull the whole vehicle along until one of the inactive rods is raised into line in the direction of travel at which point it becomes active and the active one in the opposite direction of travel becomes inactive and is then carried along with the belt in the direction of travel.

I'm not real clear on the turning, I assume like a tank he would keep one track still and turn the other, but the propulsion seems sound enough.

With regards to your device, I have read the whole thread and most of it seemed caught up with whether you could take your own ground with you. I really think that argument misses the mark.

You correctly point out the spell will work on floating castles, airships or boats, but you seem to miss that those are all being kept aloft by something. You believe the spell has a way of keep itself aloft because of the relative spacing required by the spell. I disagree.

I'll try to come up with an alternative example to make my point more clearly.

[Blacky the Blackball]

Here's a little experiment you can do at home.

Get a magnet - a nice strong one if you can, a ball bearing, and a ruler.

Duct tape the magnet to the ruler; and place the ball bearing an inch away, also on the ruler. Does the ball bearing roll towards the magnet and stick to it? Good.

Now pull the ball bearing off the magnet, and put it back an inch away again - but this time duct tape it down so it can't get any closer to the magnet.

Does the ruler start flying around the room as the ball bearing keeps trying to get closer to the magnet but every time it does the magnet moves further away? Or does it just sit there under tension trying to bend the ruler or tear the tape?

Congratulations, you have now replicated the "Tenser's Skystrider" set-up. If you can get the ruler to start flying around then I - as a DM - would let you fly around on the Tenser's Skystrider.

If you can't, then your Tenser's Skystrider fails to fly for exactly the same reason the ruler fails to fly - regardless of whether or not you actually understand what that reason is.

[N810]

i apologize but that doesn't clarify anything to me. All i see is a tank with a bunch of immovable rods in it's treadmill, and since nothing is specified, for all i know they could be either inside the treadmill, or sticking out of it, and that it's treadmill would get stuck anyway because it's trying to move the active immovable rods. If anyone else is reading this, please tell me what n810 is trying to represent with that tank.

you understand that they are turning on an off based on position right ?

... I REALY DON'T KNOW HOW TO MAKE THIS SIMPLER.

[Renduaz]

Picture the oval going around his drums as belts instead of wires and affix the rods to those belts.

As the crank is turned and the active rods can't move the belt will pull the whole vehicle along until one of the inactive rods is raised into line in the direction of travel at which point it becomes active and the active one in the opposite direction of travel becomes inactive and is then carried along with the belt in the direction of travel.

I'm not real clear on the turning, I assume like a tank he would keep one track still and turn the other, but the propulsion seems sound enough.

With regards to your device, I have read the whole thread and most of it seemed caught up with whether you could take your own ground with you. I really think that argument misses the mark.

You correctly point out the spell will work on floating castles, airships or boats, but you seem to miss that those are all being kept aloft by something. You believe the spell has a way of keep itself aloft because of the relative spacing required by the spell. I disagree.

I'll try to come up with an alternative example to make my point more clearly.

Okay, I'm going to assume that in this image ( http://i.imgur.com/kaqOuXN.jpg ), the red rods ( inactive ) are affixed on top of the belt, rather than inside it ( Like taking a belt, ripping it in half, putting a rod in the middle, then stitching the belt around it ), while the blue rods ( active ) are only affixed "to the air" below the belt ( If it was to the belt, then the belt would never move as it tugs on immovable rods ), so that the treadmill moves on the active rods which are suspended in the air as if they were ground, yes? Depending on the friction of the rods or the material of the belt, I'm not even sure if a treadmill can roll on such a surface ( two rods with air inbetween them ). Also, wouldn't the back of the vehicle roll down into the space between the two immovable rods before what you describe next happens ( This - http://i.imgur.com/5FlKaT7.jpg )? Seems very precarious. Could an actual tank's treadmill drive on two metal rods fixed into place or would it get stuck in the space between them or trip over at some point?

Now that I understand it better, I'm not sure how the device would work in travelling upwards. ( Which is what he initially portrayed - http://i.imgur.com/EvIeX30.jpg ). If the active immovable rods aren't affixed to the belt ( Our "tank treadmill" ), then the whole thing just falls off while the active rods stay exactly where he put them. If they are affixed to the belt, then the belt never moves when he pulls the crank, because it's trying to move the immovable rods along with it. Unless he succeeded on a DC 30 strength check but that's irrelevant. Even if it did move, I don't understand how this defies gravity? The tank presumably works because the belt uses friction to push itself forward over the active rods, like an actual tank on the ground. In this picture, that belt would just grind against the immovable rods, bringing the device nowhere up. Basically like a tank trying to climb a wall.


Here's a little experiment you can do at home.

Get a magnet - a nice strong one if you can, a ball bearing, and a ruler.

Duct tape the magnet to the ruler; and place the ball bearing an inch away, also on the ruler. Does the ball bearing roll towards the magnet and stick to it? Good.

Now pull the ball bearing off the magnet, and put it back an inch away again - but this time duct tape it down so it can't get any closer to the magnet.

Does the ruler start flying around the room as the ball bearing keeps trying to get closer to the magnet but every time it does the magnet moves further away? Or does it just sit there under tension trying to bend the ruler or tear the tape?

Congratulations, you have now replicated the "Tenser's Skystrider" set-up. If you can get the ruler to start flying around then I - as a DM - would let you fly around on the Tenser's Skystrider.

If you can't, then your Tenser's Skystrider fails to fly for exactly the same reason the ruler fails to fly - regardless of whether or not you actually understand what that reason is.

Oh my, here we go again. Another one of those "Equivalents of why something which relies on the laws of physics in real world doesn't work, therefore it won't work with your magical disk which defies gravity as it levitates and answers only to magic code either". Those examples were bad all the last times, and yours is bad too. The ball bearing and the magnet are both attracted to each other. When you tape them both to a ruler, they are pushed towards each other, not just the ball bearing to the magnet in one direction. Congratulations, you're a genius ( Not ).

Now, make a wild guess about which magical force, unlike real life electromagentism, is actually attracted to just one target, following it in one direction, but the target isn't exerting any kind of force on it? That's right, Tenser's Floating Disk spell description.

[tieren]

ok, I'll try again...

The system can not fly without lift, the lift needs to be sufficient to counteract gravity. While the disc disregards gravity (up to certain limits within the description of the spell) the rest of the system does not.

You indicate the disc trying to rise up to you is creating a force vector strong enough to lift the system. Nothing in the spell description says that is possible.

One fallacy is believing the disc is trying to move directly towards you. Suppose in a normal walking down the corrido example you are 20 feet ahead of the TFD walking along and come to a 5 foot stair way (45 degrees such that it rises 5 feet of height in 5 feet of distance). You walk up the stairs and stop. The TFD is 20 feet behind you, 15 feet before the stairs and 3 feet off the ground, there is nothign to indicate that any movement other than lateral is taking place until you walk 15 more feet forward and the disc encounters the elevation change in the ground. Note the disc is responding to the elevation change in the ground, it did not respond to your initial elevation change.

Similarly, assume you cast TFD on a warehouse floor and then climb up on a catwalk 15 feet above the ground and continue across the room. The disc will follow along on the floor trying to stay within range, but it won't be floating 10 feet up to get closer to you.

There simply is no lift vector without an obstacle on the ground for TFD to respond to.

[N810]

https://image.slidesharecdn.com/u6l6-160119120213/95/unit-6-lesson-5-newtons-laws-of-motion-7-638.jpg?cb=1454425811

[tieren]

https://scontent-sjc2-1.xx.fbcdn.net/v/t1.0-9/fr/cp0/e15/q65/17523043_10155216572261096_2734418020681691980_n.j pg?efg=eyJpIjoiYiJ9&oh=298fdb63400fea7ea74a978b9615ae3a&oe=5952BCAD

WORKS LIKE THIS

https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcQn59nso4K2hwVrNvl9_hzdYA83qN8Fc kXwh0SUaMcNOIYCi3YhBA

ACTIVE IMMOVEABLE RODS = GROUND
both are immobile, notice how only the bottom part of the tank treads touch the ground, same thing.

The thing to keep in mind is the tank analogy. As the tank is moving, the track that is in contact with the ground doesn't move at all, it remains in contact with the exact same piece of ground.

All of the propulsion rods are affixed permanently in the belt. When he activates two and they become affixed in space, and then he attempts to advance the belt, what will happen is the entire device will move instead of the belt where the rods are. As it moves along more belt will be applied in the plane of the affixed rods, and the same amount of belt will be removed from behind them, until a third rod is in the same plane as the affixed ones, when that happens the one in the back becomes unaffixed and the one that just moved up becomes affixed.

The tread isn't running along rods hanging there, they are holding that part of the track stationary so the device moves.

[Renduaz]

ok, I'll try again...

The system can not fly without lift, the lift needs to be sufficient to counteract gravity. While the disc disregards gravity (up to certain limits within the description of the spell) the rest of the system does not.

You indicate the disc trying to rise up to you is creating a force vector strong enough to lift the system. Nothing in the spell description says that is possible.

One fallacy is believing the disc is trying to move directly towards you. Suppose in a normal walking down the corrido example you are 20 feet ahead of the TFD walking along and come to a 5 foot stair way (45 degrees such that it rises 5 feet of height in 5 feet of distance). You walk up the stairs and stop. The TFD is 20 feet behind you, 15 feet before the stairs and 3 feet off the ground, there is nothign to indicate that any movement other than lateral is taking place until you walk 15 more feet forward and the disc encounters the elevation change in the ground. Note the disc is responding to the elevation change in the ground, it did not respond to your initial elevation change.

Similarly, assume you cast TFD on a warehouse floor and then climb up on a catwalk 15 feet above the ground and continue across the room. The disc will follow along on the floor trying to stay within range, but it won't be floating 10 feet up to get closer to you.

There simply is no lift vector without an obstacle on the ground for TFD to respond to.

There are no certain limits related to gravity in the spell. Only limits on weight, distance, and magical height off the ground. Actually there is something which says the force vector is enough to lift the system. The disk can carry up to 500 pounds on it's upper side while unaffected by gravity. Whether it's levitating 3' off the ground, or rising 8' to reach a player who climbed a 8' stage, it can always carry up to 500 pounds on it's top side while doing so. And if the upper shell sitting on the disk, as well as the beams and the chair attached to it, and the player sitting on the chair, are less than 500 pounds in weight, the device works.

Now as for player elevation versus ground elevation, I talked about this with CdrMilitant. If it works as you say, then the contraption would only move forward like a car as the disk goes forward, but never upward. A possible way to overcome this is through an obstacle whose length is no longer than 10', so the disk thinks it can rise above it. If we have a 3' diameter disk, and 4' diameter shell, we'd need a slit right in front of the disk's edge that we can slide some kind of surface through, so that the disk perceives it as an obstacle like a wall, and attempts to rise up more than 3' from it's ground ( The lower casing ) to reach it, thus also raising the upper shell, and the obstacle in front of it, and perpetual vertical rise. Now whenever you'd want to stop that, remove the surface from the slit and outside the shell, and the disk will revert to moving forward. Although this will be more of a rapidly angled diver as it falls very fast forward until you insert the surface again.

Now, in your warehouse example, you once again make the catwalk more than 10' above the disk. What if it's a catwalk which is 8' above the ground and I continue across the room? Will the disk move along the floor or rise horizontally to reach me? I also made an image for you to ponder upon - http://i.imgur.com/N0WBHCG.png

[Renduaz]

The thing to keep in mind is the tank analogy. As the tank is moving, the track that is in contact with the ground doesn't move at all, it remains in contact with the exact same piece of ground.

All of the propulsion rods are affixed permanently in the belt. When he activates two and they become affixed in space, and then he attempts to advance the belt, what will happen is the entire device will move instead of the belt where the rods are. As it moves along more belt will be applied in the plane of the affixed rods, and the same amount of belt will be removed from behind them, until a third rod is in the same plane as the affixed ones, when that happens the one in the back becomes unaffixed and the one that just moved up becomes affixed.

The tread isn't running along rods hanging there, they are holding that part of the track stationary so the device moves.

What do you mean the track isn't moving? Of course it is. ( https://www.youtube.com/watch?v=uuLzLt1Q7z8 ) And if he affixes two rods to a belt, be it through whatever means ( Glue? Nails? ), and then he attempts to advance the belt, what happens is that the belt tugs on whatever it is which affixes the active rods to it, which in turn tugs on the rods, and nothing moves. Also even if it did work, how would it FLY? how does it go UP in the air by itself? His initial diagram made the design vertical.

[Mhl7]

What do you mean the track isn't moving? Of course it is.

You clearly don't understand how the track of a tank works. Look at this video
https://www.youtube.com/watch?v=rtOLG3DXWEE
at 0.48.

You can clearly see that the part of the track touching the ground is stationary. Once you understand this, you also understand the movable rods trick.

[Zorku]

I apologize but that doesn't clarify anything to me. All I see is a tank with a bunch of immovable rods in it's treadmill, and since nothing is specified, for all I know they could be either inside the treadmill, or sticking out of it, and that it's treadmill would get stuck anyway because it's trying to move the active immovable rods. If anyone else is reading this, please tell me what N810 is trying to represent with that tank.
Simply put,

When you've got tank tread in contact with the ground, that part does not move (static friction.)
When tank treads lift up off of the ground they move up, then rapidly backward, then back down until they touch the ground.

The rods that are active count as "the ground" (it's simpler to think about this if we make that the bottom of the treads, but you could configure this in other ways,) and we activate them slightly after they come down past the curve, then deactivate them before we need them to lift up and swing over the top to return to a position where we will activate them.


In this picture, that belt would just grind against the immovable rods, bringing the device nowhere up.
Ok, this makes it clearer. On a tank, the belt itself is mostly stationary (the part that's on the ground,) and you've basically got a gear (or several) that rolls over the tread. That gear is moving the tank along just like tires would move a car, but instead of tires on asphalt, you've got a gear on the inside of the tread.

When you look at the tread as a belt it's easy to miss what's actually exerting force where, and if you think that the belt has to be spun you'd expect some weird force on the immovable rods, but we don't need anything like that. If you're still having a hard time picturing this, imaging that we have this big long strip of tread that wasn't a loop. It's just wound up like a roll of toilet paper, and it's got hundreds of immovable rods down the length of it. Now you've got a machine with a few rollers that can feed the tread past them like it's a printer (or w/e.) You turn on the first rod then climb up a ways and turn on the next rod and climb up and turn on the next rod and... eventually empty the roll. That much makes sense, yeah? You basically built a ladder like this.

So what we're going to do next is turn the rods back off when they go past the last roller, and roll this tread back up behind us. You can climb just as high as before, but now you've taken most of the ladder with you (which is fine, cuz immovable.) Still works fine. Rollers only ever pushed off of stuff held in place by active immovable rods, only ever moved inactive immovable rods when rolling this back up behind the rollers.

Last thing we do is make it so that instead of rolling up behind it, the inactive rods part just swings round back to the front to be used again.


What do you mean the track isn't moving? Of course it is. ( https://www.youtube.com/watch?v=uuLzLt1Q7z8 ) And if he affixes two rods to a belt, be it through whatever means ( Glue? Nails? ), and then he attempts to advance the belt, what happens is that the belt tugs on whatever it is which affixes the active rods to it, which in turn tugs on the rods, and nothing moves. Also even if it did work, how would it FLY? how does it go UP in the air by itself? His initial diagram made the design vertical.
Nah. You only ever tug on the parts of the belt that are stationary.

This thing doesn't so much "fly." It "climbs." It's climbing off of immovable rods, and it keeps activating the next rod higher up in the air than the last one.

Like, get a rubber band and pin it to a table with your finger in the middle of the loop. You see how the loop can roll one way, or roll the other, and it's all free to move except for the section your finger has pinned, yeah?

[Renduaz]

Simply put,

When you've got tank tread in contact with the ground, that part does not move (static friction.)
When tank treads lift up off of the ground they move up, then rapidly backward, then back down until they touch the ground.

The rods that are active count as "the ground" (it's simpler to think about this if we make that the bottom of the treads, but you could configure this in other ways,) and we activate them slightly after they come down past the curve, then deactivate them before we need them to lift up and swing over the top to return to a position where we will activate them.


Ok, this makes it clearer. On a tank, the belt itself is mostly stationary (the part that's on the ground,) and you've basically got a gear (or several) that rolls over the tread. That gear is moving the tank along just like tires would move a car, but instead of tires on asphalt, you've got a gear on the inside of the tread.

When you look at the tread as a belt it's easy to miss what's actually exerting force where, and if you think that the belt has to be spun you'd expect some weird force on the immovable rods, but we don't need anything like that. If you're still having a hard time picturing this, imaging that we have this big long strip of tread that wasn't a loop. It's just wound up like a roll of toilet paper, and it's got hundreds of immovable rods down the length of it. Now you've got a machine with a few rollers that can feed the tread past them like it's a printer (or w/e.) You turn on the first rod then climb up a ways and turn on the next rod and climb up and turn on the next rod and... eventually empty the roll. That much makes sense, yeah? You basically built a ladder like this.

So what we're going to do next is turn the rods back off when they go past the last roller, and roll this tread back up behind us. You can climb just as high as before, but now you've taken most of the ladder with you (which is fine, cuz immovable.) Still works fine. Rollers only ever pushed off of stuff held in place by active immovable rods, only ever moved inactive immovable rods when rolling this back up behind the rollers.

Last thing we do is make it so that instead of rolling up behind it, the inactive rods part just swings round back to the front to be used again.


Nah. You only ever tug on the parts of the belt that are stationary.

This thing doesn't so much "fly." It "climbs." It's climbing off of immovable rods, and it keeps activating the next rod higher up in the air than the last one.

Like, get a rubber band and pin it to a table with your finger in the middle of the loop. You see how the loop can roll one way, or roll the other, and it's all free to move except for the section your finger has pinned, yeah?

Okay, first things first. I keep hearing all that jazz about "affixed rods" and the belt yet nobody explains how they are affixed or where which is very important. I look at this picture - http://i.imgur.com/zI0CmAa.jpg , all I see is is a gray loop representing the belt apparently, and circles in the middle representing rods. Forget the active ones for now. Let's talk about the red ones. How are they "affixed" to that belt? Are they on the side to the right, the side to the left, or if the belt is thick enough, somehow inserted through the middle? What affixes them? Right now they're just plain old rods when they're inactive. What keeps them on the belt? Glue? Some kind of strap?

[LordCdrMilitant]

Actually, the rod machine works quite well, as far as I can see.

The bottom rods are active, and serve as stationary points. All the rods are worked into the belt as links in the track. As the return sprocket reaches the first active rod, the fixed rod is deactivated, allowing the track to pick the now-movable rod up and carry it to the front of the machine, where it sets it down and re-fixes it, allowing the machine to move forward over the rods.

It works exactly like a tank track.


Are you aware as to how one uses 3 immovable rods to create a ladder? It works on the same principle, just automating the process by distributing them along a belt.


My calculations imply a minimum of 5 immovable rods to assure the machine's stability, with another requires for each axis you wish the machine to rotate in.


Immovable rods are moderately expensive, though, and by the time you can buy those rods with your WBL, you can also fly under your own power.


As far as achieving flight as a level 1 character, it would almost certainly be easier to seek means to achieving sufficient thrust than to find a rules loophole. Once you have some thrust, you can achieve flight using a regular old airfoil.

Alternatively, Create Bonfire can make a good hot-air balloon.

And, as I suggested earlier, you could potentially use the electricity from Shocking Grasp to separate Hydrogen and Oxygen in water, and then have yourself a zeppelin. It requires 1-2 V to separate water IIRC. You could charge a capacitor with a shock spell, then discharge the capacitor to separate a little bit of hydrogen gas and oxygen gas. You could just shock the non-GND electrode, too. Rinse and repeat for a long time, and soon you'll be able to fill up your zeppelin's gas bag. You could contract out the undergraduate class at the local mages' college to help you with this task. You could conceivably make a rocket with your hydrogen too, but you lack the equipment to compress it to liquid state and the metallurgical talent to make the motor not burn itself up.

[ShikomeKidoMi]

I may have missed something, but how are you steering this device in the OP?

If you're using a machine to keep yourself 20' away from the disc and slightly above it so that it moves towards you and upwards, wouldn't it continuously move in a straight line with no way to change direction? And don't say "Mage Hand", because moving you requires moving a lot more than 10 lbs, which is the spell's upper limit.

As near as I can tell, you'd get, at best, a system that moved in one direction continuously until you bailed out.

[Renduaz]

Actually, the rod machine works quite well, as far as I can see.

The bottom rods are active, and serve as stationary points. All the rods are worked into the belt as links in the track. As the return sprocket reaches the first active rod, the fixed rod is deactivated, allowing the track to pick the now-movable rod up and carry it to the front of the machine, where it sets it down and re-fixes it, allowing the machine to move forward over the rods.

It works exactly like a tank track.


Are you aware as to how one uses 3 immovable rods to create a ladder? It works on the same principle, just automating the process by distributing them along a belt.


My calculations imply a minimum of 5 immovable rods to assure the machine's stability, with another requires for each axis you wish the machine to rotate in.


Immovable rods are moderately expensive, though, and by the time you can buy those rods with your WBL, you can also fly under your own power.


As far as achieving flight as a level 1 character, it would almost certainly be easier to seek means to achieving sufficient thrust than to find a rules loophole. Once you have some thrust, you can achieve flight using a regular old airfoil.

Alternatively, Create Bonfire can make a good hot-air balloon.

And, as I suggested earlier, you could potentially use the electricity from Shocking Grasp to separate Hydrogen and Oxygen in water, and then have yourself a zeppelin. It requires 1-2 V to separate water IIRC. You could charge a capacitor with a shock spell, then discharge the capacitor to separate a little bit of hydrogen gas and oxygen gas. You could just shock the non-GND electrode, too. Rinse and repeat for a long time, and soon you'll be able to fill up your zeppelin's gas bag. You could contract out the undergraduate class at the local mages' college to help you with this task. You could conceivably make a rocket with your hydrogen too, but you lack the equipment to compress it to liquid state and the metallurgical talent to make the motor not burn itself up.

I understand how the tank treadmill works and the whole process with a belt carrying rods in front of one another, but nobody is answering my question, which you're probably missing the importance of - How are all the rods "worked into the belt" as links? Listen, I just bought 4 immovable rods from a merchant, and then I bought a belt, okay? Those rods are in my hand or my bag right now. I need to install them on the belt first before even building the thing. How do I do it? With glue? With nails? With what? If it helps you, answer me only about the inactive rods.

Now, you want to grab 2 rods, push their button next to each other in the air so they serve as ground for your tank treadmill, yes? So you do that, they're now affixed to the air, serving as your stationary points. And when your first rod is deactivated, it falls down. How does your track belt "pick it up" exactly? That active rod isn't attached to the belt by any means, it's just affixed in the air. Or is it attached to the belt? If so, tell me by what means.

Secondly, even if I ignored that, how would the device work vertically, "climbing up into the air" as shown by OP in his first image? That would be like trying to make a tank treadmill climb up a vertical wall. Nothing would happen. Gravity would pull the tank down. A tank treadmill can't climb a vertical surface.

Now when it comes to alternative flight ideas, I'm not sure about the bonfire, but you have to remember that it would have to be something your character could think of. And your character has absolutely no way of ever knowing anything about the hydrogen and oxygen in the water, nor do we even know if there's hydrogen and oxygen in the D&D universe, nor do we have a capacitor, and Shocking Grasp only targets creatures by RAW. There are spells like Fire Bolt which target objects too, but Shocking Grasp only works if you target a creature to use it on, and could theoretically shock only the creature and nothing else around it.


I may have missed something, but how are you steering this device in the OP?

If you're using a machine to keep yourself 20' away from the disc and slightly above it so that it moves towards you and upwards, wouldn't it continuously move in a straight line with no way to change direction? And don't say "Mage Hand", because moving you requires moving a lot more than 10 lbs, which is the spell's upper limit.

As near as I can tell, you'd get, at best, a system that moved in one direction continuously until you bailed out.

I actually just realized the device is paradoxical because the rim of the shell in front of the disk, being attached to both upper and lower casing, can qualify as either an obstacle coming out of the ground, or as part of the upper shell being carried by the disk, in which case it doesn't qualify as an obstacle. A way to solve this might be to to make the upper shell and it's rim only a half circle rather than a full one, so that the front direction of the disk is exposed, thereby posing no obstacle save for the remaining 1' stretch of ground from the lower shell below it, and the disk's friction on the upper shell half-circle should prevent the disk from sliding forward without the upper shell, and now if the disk's pathfinding is in relation to it's ground rather than the player, you'd just have to make the lower shell casing rotate along a vertical axis ( So that it resembles a slope instead of flat ground when you want it to ), and then the disk will actually rise diagonally as I wanted to. Which you could adjust from your chair using mage hands, since the lower shell casing is what's being carried by the disk and that mechanism wouldn't weigh much. And for moving the chair down from it's pulley, you'd just pull the chain next to you yourself, like someone lowering himself into a wellspring using both ends of a rope.

For steering left and right, two other chain and pulley mechanisms will be attached from the chair's sides to the shell's sides, and you'd pull them to the direction you want to steer to, like handles on a motorcycle, to tilt the chair slightly left or right from it's direct path in front of the disk. Granted you wouldn't have much range of motion like that, but eventually you could make the turn as the disk follows you at a curve. This ( http://i.imgur.com/KjiXOUr.png ) is the new design, with front and side view.

[N810]

Fine whatever use sovereign glue for all I care,
there now it's permanently and forever attached,
you happy now ????

[Renduaz]

Fine whatever use sovereign glue for all I care,
there now it's permanently and forever attached,
you happy now ????

No, because if you attach any rod to your belt, then that rod can never be activated. If the active rods are attached, then they can't be ground for a treadmill. Imagine it as two tree trunks with a tank on top of them, and the surfaces of those tree trunks being glued to the bottom of the treadmill ( And also imagine the glue is strong enough to keep them in place ). That tank's treadmill is going to get stuck because when it's belt tries to get pulled back up or down "Like a printer", it tugs on the glue which tugs on the trunks and if those trunks are as immovable as an immovable rods, that tank's belt gets stuck, the wheel inside it continuing to rotate in place, like those of a car in mud, inside a belt which can never leave the exact spot it's at.

Now if your active rods resemble actual ground by not being attached to the belt, but rather being fixed in the air, with only the inactive rods being attached to the belt, Then your belt would require some sort of machinery which decouples one inactive rod from itself when that inactive rod arrives at the same axis as the fixed rods, then fixes it in place, and also a mechanism which couples ( Picks up ) the active rod fixed to the air in the back after deactivating it, so that it's carried by belt instead of just falling down.

But even with something like that, I still don't understand how such a treadmill would be able to climb on rods placed vertically, instead of just falling off or never rising up like an actual tank trying to climb a wall or a building.

[N810]

https://img.memesuper.com/53d8713b3ca5103cbd81fc93f0b9fdb8_jackie-chan-meme-by-jackie-meme_512-384.jpeg

[Renduaz]

https://img.memesuper.com/53d8713b3ca5103cbd81fc93f0b9fdb8_jackie-chan-meme-by-jackie-meme_512-384.jpeg

The others I've talked with about your design know how to elaborate on it better, so I'll wait for one of them to assist me in addressing the means of the rods attachment to the belt and how it couples rod from the back and decouples them at the front to create an indefinitely lasting ground for itself, like a hamster running from one of your hands to another, and then to explain how your treadmill can climb in the air upwards. I'm not sure how adept you are with English or writing long posts, so I'm just going to wait for CdrMilitant to respond to my query.

[McNinja]

In the in-game time it takes you to get all of this stuff, you could just make 20k gold adventuring and buy an actual airship.

[Renduaz]

In the in-game time it takes you to get all of this stuff, you could just make 20k gold adventuring and buy an actual airship.

The only stuff you'd need for the TFD device is two thin metal plates, some kind of handle, 3 thin metallic poles, 3 20+ feet chainlinks and a seat. You could probably get those from any blacksmith for the same value as the weight of all the components in iron or steel.

[N810]

Do you know understand Newton's 3rd law of motion ???

[Renduaz]

Do you know understand Newton's 3rd law of motion ???

Yes, I do. What I don't understand ( And I think you and other people don't understand ) is the 3D placement of the rods in your belt or how a player who is first building the device is going to attach them to the belt in the first place. and since you won't write replies which are more than 5 lines in length, and won't provide a step-by-step guide of the materials that a player must obtain to build your device, and then the sequences and manner in which he connects them with each other, then I have to talk about these things with the posters who answer these questions.

[Mhl7]

Yes, I do. What I don't understand ( And I think you and other people don't understand ) is the 3D placement of the rods in your belt or how a player who is first building the device is going to attach them to the belt in the first place. and since you won't write replies which are more than 5 lines in length, and won't provide a step-by-step guide of the materials that a player must obtain to build your device, and then the sequences and manner in which he connects them with each other, then I have to talk about these things with the posters who answer these questions.

Do you understand how a tank works?

If yes, suppose that each segment of the track of the tank is an immovable rod.
Suppose that they are turned off while on the upper side of the wheels and that they are turned on while on the lower side (the exact mechanism is not important).
Now place that tank in mid air. It will float because it sits on two rows of immovable rods.
Now activate the tank and move it forward. Its wheels will start to roll on the bottom tracks, which are made of immovable rods.
In the meanwhile you must deactivate the last rod of the bottom row of the track, so that it is movable and the movement of the wheel will lift it and move it forward.
At the same time another rod will be added in front and activated.

[Renduaz]

Do you understand how a tank works?

If yes, suppose that each segment of the track of the tank is an immovable rod.
Suppose that they are turned off while on the upper side of the wheels and that they are turned on while on the lower side (the exact mechanism is not important).
Now place that tank in mid air. It will float because it sits on two rows of immovable rods.
Now activate the tank and move it forward. Its wheels will start to roll on the bottom tracks, which are made of immovable rods.
In the meanwhile you must deactivate the last rod of the bottom row of the track, so that it is movable and the movement of the wheel will lift it and move it forward.
At the same time another rod will be added in front and activated.

You really should read what I said in my replies before trying to give an explanation. You're just repeating what I already know, and it doesn't work. Suppose that each segment of the track of the tank is an immovable rod, huh? Yes. Yes, I do suppose that, and I do know how a tank works. So let's suppose that. And while on the upper side of the treadmill, they're turned off. Yeah, no problem. And they're turned on while on the lower side, and yes, that fixes your tank into place while in the air.

>Now activate the tank and move it forward.

No, no. NO. NO. NO. NO, and NO. This is why you had to read what I said. When you deactivate the last rod on the bottom of the track, *it* becomes moveable, but the movement of the wheel never lifts it like the belt of an actual tank, which is rolled up and then forward. Your deactivated rod is stuck in place because it's attached to a belt which is attached to immovable rods, which makes that belt unable to roll. A tank's treadmill isn't attached to it's ground. It sits on top of the ground. What you're trying to do would be like drilling a rod into the ground and linking it to the tank's treadmill. It would get stuck.

[Mhl7]

No, because if you attach any rod to your belt, then that rod can never be activated. If the active rods are attached, then they can't be ground for a treadmill. Imagine it as two tree trunks with a tank on top of them, and the surfaces of those tree trunks being glued to the bottom of the treadmill ( And also imagine the glue is strong enough to keep them in place ). That tank's treadmill is going to get stuck because when it's belt tries to get pulled back up or down "Like a printer", it tugs on the glue which tugs on the trunks and if those trunks are as immovable as an immovable rods, that tank's belt gets stuck, the wheel inside it continuing to rotate in place, like those of a car in mud, inside a belt which can never leave the exact spot it's at.


That's it! Take exactly this example, except that your trunk (immovable rod) are deactivated as soon as the belt tries to pull them back (so that they are not immovable anymore). In this way they can be pulled up and transported to the front where they are activated again, and so on..

[N810]

deactivated rod is stuck in place because it's attached to a belt which is attached to immovable rods
This is a false assumption.
immoveable rods do no turn things touching them rigid an immoveable.
they are only them selves immoveable. when activated.

[Mhl7]

A tank's treadmill isn't attached to it's ground. It sits on top of the ground. What you're trying to do would be like drilling a rod into the ground and linking it to the tank's treadmill. It would get stuck.

Did you see the video that I posted? The tank in slow motion? The lower part of a the treadmill IS static! Every juncture of the belt stays in the same spot (respect to the ground) until it is picked up again. The wheels of the treadmill roll over it.

[Renduaz]

That's it! Take exactly this example, except that your trunk (immovable rod) are deactivated as soon as the belt tries to pull them back (so that they are not immovable anymore). In this way they can be pulled up and transported to the front where they are activated again, and so on..

If you deactivate one of them, like the last one, the belt can't pull it back to the top, because your deactivated rod is still attached to a segment of the belt which is attached to the active rod ( Front bottom, first rod ). The wheels start spinning, attempting to pull the belt up. It tries to pull your deactivated rod along with it. The deactivated rod tugs on the segment of belt in front of it as it's trying to get rolled backwards and up with the belt. That segment of the belt in front tugs on the active immovable rod which is in front of it. And it never moves.

It will only be able to rotate like an actual tank belt if you deactivated both. But then there's nothing more affixing that tank to the air, and it starts falling as the wheels rotate the belt.



Did you see the video that I posted? The tank in slow motion? The lower part of a the treadmill IS static! Every juncture of the belt stays in the same spot (respect to the ground) until it is picked up again. The wheels of the treadmill roll over it.

Yes I did. It's static, but it isn't attached to the ground. It on top of it. Meanwhile your active immovable rods is static and it's also attached to the belt and *fixed into the air* in one spot that it can't get away from. That would be equivalent of someone pushing a stake through that tank's tread exactly where your active rod is, and lodges that stake into the ground beneath the treadmill.

[Renduaz]

This is a false assumption.
immoveable rods do no turn things touching them rigid an immoveable.
they are only them selves immoveable. when activated.

Great, now you understand the problem. You're just failing to understand the chain reaction. If I take an actual treadmill like the one you have at the gym, and I put 2 immoveable rods on it by gluing them or whatever, the machine's belt completely halts in place as it tries to take those rods with it ( Like a factory line moving forward items along a belt ), but there is now a 8,000 pound force preventing them from ever leaving the exact spot where you activated them on. So the belt is now like a guy trying to pull a house along with him. It gets stuck or torn into shreds. It doesn't matter if you turn the rod in the front off. It can now move forward along with the belt since it's no longer magically stuck, but the rod behind it still is, so neither the belt nor the inactive rod on top of it can get away from that fixed rod.

[Mhl7]

If you deactivate one of them, like the last one, the belt can't pull it back to the top, because your deactivated rod is still attached to a segment of the belt which is attached to the active rod ( Front bottom, first rod ). The wheels start spinning, attempting to pull the belt up. It tries to pull your deactivated rod along wit hit. The deactivated rod tugs on the segment of belt in front of it as it's trying to get rolled backwards and up with the belt. That segment of the belt in front tugs on the active immovable rod which is in front of it. And it never moves.

It will only be able to rotate like an actual tank belt if you deactivated both. But then there's nothing more affixing that tank to the air, and it starts falling as the wheels rotate the belt.

Yes I did. It's static, but it isn't attached to the ground. It on top of it. Meanwhile your active immovable rods is static and it's also attached to the belt and *fixed into the air* in one spot that it can't get away from. That would be equivalent of someone pushing a stake through that tank's tread exactly where your active rod, and lodges that stake into the ground beneath the treadmill.

Yes, it would be equivalent. And the tank would still move forward, provided that the stake is removed at the correct time (same time you deactivate the rod).

My last try: pick a model tank (or whatever vehicle that fits in your hand and has a treadmill) put it in a vertical position. Fix one point of the bottom tread with two fingers. Use your other hand to move the tank up. You can clearly see that the tank moves, "climbing on the air", while the piece of the tread that you are holding in hand is fixed (literally). When the time comes for the wheel to pick it up, release it.

I am not answering anymore, spend some time with yourself and try to understand it.

[Renduaz]

Yes, it would be equivalent. And the tank would still move forward, provided that the stake is removed at the correct time (same time you deactivate the rod).

My last try: pick a model tank (or whatever vehicle that fits in your hand and has a treadmill) put it in a vertical position. Fix one point of the bottom tread with two fingers. Use your other hand to move the tank up. You can clearly see that the tank moves, "climbing on the air", while the piece of the tread that you are holding in hand is fixed (literally). When the time comes for the wheel to pick it up, release it.

I am not answering anymore, spend some time with yourself and try to understand it.

You don't have to answer anymore, but that might work because the bottom tread can slide through my fingers. Moving across one finger and sliding beneath the other. My finger isn't threaded through the depth of the treadmill itself. And, none of that still explains how such a tank would climb in the air vertically. You claim it works just like an actual tank. And an actual tank can't climb over a wall.

[LordCdrMilitant]

Now when it comes to alternative flight ideas, I'm not sure about the bonfire, but you have to remember that it would have to be something your character could think of. And your character has absolutely no way of ever knowing anything about the hydrogen and oxygen in the water, nor do we even know if there's hydrogen and oxygen in the D&D universe, nor do we have a capacitor, and Shocking Grasp only targets creatures by RAW. There are spells like Fire Bolt which target objects too, but Shocking Grasp only works if you target a creature to use it on, and could theoretically shock only the creature and nothing else around it.

Find a sufficiently conductive creature, such as a peasant in metal armor! Now he's a legitimate target for your zapping. If the world contains airships as is, you do know what hydrogen is. If not, use that INT 20 (17 if you use standard array or points-buy) your wizard has for something and get on with the science! Publish your work as your doctorate thesis; you'll revolutionize the fantasy theory of the elements. For the record, Hydrogen was first observed in 1671, but not identified for what it was in 1783.



You really should read what I said in my replies before trying to give an explanation. You're just repeating what I already know, and it doesn't work. Suppose that each segment of the track of the tank is an immovable rod, huh? Yes. Yes, I do suppose that, and I do know how a tank works. So let's suppose that. And while on the upper side of the treadmill, they're turned off. Yeah, no problem. And they're turned on while on the lower side, and yes, that fixes your tank into place while in the air.

>Now activate the tank and move it forward.

No, no. NO. NO. NO. NO, and NO. This is why you had to read what I said. When you deactivate the last rod on the bottom of the track, *it* becomes moveable, but the movement of the wheel never lifts it like the belt of an actual tank, which is rolled up and then forward. Your deactivated rod is stuck in place because it's attached to a belt which is attached to immovable rods, which makes that belt unable to roll. A tank's treadmill isn't attached to it's ground. It sits on top of the ground. What you're trying to do would be like drilling a rod into the ground and linking it to the tank's treadmill. It would get stuck.

Why would it be unable to lift it up? Immovable rods only make themselves immobile, not what else they're touching. If I attach a one end of a chain to an immovable rod, the chain doesn't become frozen in place, it hangs from it and I can swat it around like a cat. And, do you want to know what happens if you bolt links of a tank's track to the ground? The tank is able to move forwards and backwards until the first or last road wheel passes a secured link and the tank tries to lift up that link, at which point the tank either has to stop moving or the offending link has to become disconnected from the ground. If that link is unpinned, the tank can proceed until the next pinned link is pulled up.

If I bolt every track link down as soon as it touches the ground and unbolt it when the tank tries to lift it up, the tank wouldn't notice. It would actually benefit, because it would have perfect traction.

[Renduaz]

Find a sufficiently conductive creature, such as a peasant in metal armor! Now he's a legitimate target for your zapping. If the world contains airships as is, you do know what hydrogen is. If not, use that INT 20 (17 if you use standard array or points-buy) your wizard has for something and get on with the science! Publish your work as your doctorate thesis; you'll revolutionize the fantasy theory of the elements. For the record, Hydrogen was first observed in 1671, but not identified for what it was in 1783.




Why would it be unable to lift it up? Immovable rods only make themselves immobile, not what else they're touching. If I attach a one end of a chain to an immovable rod, the chain doesn't become frozen in place, it hangs from it and I can swat it around like a cat. And, do you want to know what happens if you bolt links of a tank's track to the ground? The tank is able to move forwards and backwards until the first or last road wheel passes a secured link and the tank tries to lift up that link, at which point the tank either has to stop moving or the offending link has to become disconnected from the ground. If that link is unpinned, the tank can proceed until the next pinned link is pulled up.

If I bolt every track link down as soon as it touches the ground and unbolt it when the tank tries to lift it up, the tank wouldn't notice. It would actually benefit, because it would have perfect traction.

Alright, let's say I understand that, since it was all very confusingly explained. I've been told that the active rods are the "ground", so I imagined them as affixed to the air but not the belt at first, but if they're affixed both to the belt ( I'm still not getting an answer on how the rods are attached to the belt like links in a treadmill. Glue? Welding? What? ) , and to the air while at the bottom of the track, then that makes them all part of the treadmill, while the air is actually like the "ground" which the active rods are magically standing on ( Being magically fixed to that point in space ).

But that still doesn't explain how the device "climbs up" through the air vertically like a treadmill as the OP first portrayed it. Basically take a tank and a skyscraper's flat vertical wall, flip the tank so that the treadmill touches the wall ( And let's think of the tank as not flipping over backward ), and then we take one link of that treadmill at the "bottom" of the track, at the higher part of the segment ( Let's say 8 feet ) and somehow attach it to the skyscraper's wall at that spot. And the other rod is currently deactivated so it doesn't matter. If I turn on the tank, it won't start climbing on the vertical wall like it works on a horizontal surface, because gravity pulls it down. It won't move an inch when turned on.

The bottom wheels move forward on the static belt like a car on a road. But a car's wheels can't move up on a wall, which is our vertical belt.

[N810]

tanks don't use belts and wheels, they use chain-link and gears.

[Renduaz]

tanks don't use belts and wheels, they use chain-link and gears.

Yes, that's what I meant. I'm just calling the chainlink a "belt" to more clearly denote it's role and the gears I call the wheels.

[N810]

You have 100% traction, you can go in any direction you want.
Just point the whole thing in the right direction before you turn on the rods.

[Renduaz]

You have 100% traction, you can go in any direction you want.
Just point the whole thing in the right direction before you turn on the rods.

Okay, that doesn't help me, so I'll wait for an explanation from CdrMilitant.

[LordCdrMilitant]

Okay, that doesn't help me, so I'll wait for an explanation from CdrMilitant.

I'm flattered.

http://imageshack.com/a/img923/9324/Lhze5q.gif

Here's a gif I made quickly of a tank track in operation. As you can see, the marked link [with a black circle], is stationary while the link is active [red].

Blue links are links that are mobile and red links are links that are static [secured by their immovable rod]. Strictly speaking, not every link needs an immovable rod for the machine to work, there just needs to be at least 2 active ones at a time to ensure stability [therefore, you need 5 rods, evenly space].

It's worth mention that the pair of immovable rods can support a total weight of 8 tons, so that's our upper limit for weight, since it's cheaper to make the machine lighter and smaller than it is to buy additional rods. I doubt the contraption would weight 8 tons, though, since while a tank can weigh 50 tons or more, most of that weight is in armor plating.



Also, a tank has a drive sprocket, a idler wheel, and a number of road wheels and return rollers. But specific terminology is neither here nor there.


A tank can climb a wall, provided that the following conditions are met:
1: the tank's center of mass is between the first and last road wheels horizontally, so it won't flip backwards and it's tracks stay on the ground.
2: the tank has enough horsepower to move itself upwards.
3: the tank has enough traction [friction force] not to slide.
The immovable rod machine has 8 tons of force preventing itself from losing traction or rolling over onto it's back, and ideally had enough horsepower to push itself along.

You can prove this to yourself with a loop of scotch tape.

[Renduaz]

I'm flattered.

http://imageshack.com/a/img923/9324/Lhze5q.gif

Here's a gif I made quickly of a tank track in operation. As you can see, the marked link [with a black circle], is stationary while the link is active [red].

Blue links are links that are mobile and red links are links that are static [secured by their immovable rod]. Strictly speaking, not every link needs an immovable rod for the machine to work, there just needs to be at least 2 active ones at a time to ensure stability [therefore, you need 5 rods, evenly space].

It's worth mention that the pair of immovable rods can support a total weight of 8 tons, so that's our upper limit for weight, since it's cheaper to make the machine lighter and smaller than it is to buy additional rods. I doubt the contraption would weight 8 tons, though, since while a tank can weigh 50 tons or more, most of that weight is in armor plating.



Also, a tank has a drive sprocket, a idler wheel, and a number of road wheels and return rollers. But specific terminology is neither here nor there.

I actually already managed to conceive somehow of how that would work for a device that drives forward horizontally ( And your gif actually only made it more confusing ), but I'm asking about the vertical application ( THIS - http://i.imgur.com/kTCrMt3.jpg ) which OP wanted to make, that would "climb up the air". An actual tank can't climb up a wall. So how would this thing climb up in the air?

Something with the design is also very wrong. It's too much of a perfectly symmetrical oval, it's not like an actual tank's treadmill ( http://i.imgur.com/cyluuPM.jpg ). There isn't enough length of treadmill for the bottom to remain stationary while the upper part and sides move until the cycle reaches the links in the bottom. Whereas in OP's picture the treadmill are too tightly coiled around those gears, at a perfect oval, which doesn't appear to leave room for a stationary bottom part. One link gets tugged, and the whole thing needs to rotate. I think this is what confused me at the start.

But even if he made it like an actual tank's treadmill, I don't understand how a tank's treadmill would climb up in the air.

[LordCdrMilitant]

I actually already managed to conceive somehow of how that would work for a device that drives forward horizontally ( And your gif actually only made it more confusing ), but I'm asking about the vertical application ( THIS - http://i.imgur.com/kTCrMt3.jpg ) which OP wanted to make, that would "climb up the air". An actual tank can't climb up a wall. So how would this thing climb up in the air?

Something with the design is also very wrong. It's too much of a perfectly symmetrical oval, it's not like an actual tank's treadmill ( http://i.imgur.com/cyluuPM.jpg ). There isn't enough length of treadmill for the bottom to remain stationary while the upper part and sides move until the cycle reaches the links in the bottom. You see how the length of blue links is longer than the length of the red at any given time in your .gif, like that of an actual tank? Whereas in OP's picture the treadmill are too tightly coiled around those gears, at a perfect oval, which doesn't appear to leave room for a stationary bottom part. One link gets tugged, and the whole thing needs to rotate. I think this is what confused me at the start.

But even if he made it like an actual tank's treadmill, I don't understand how a tank's treadmill would climb up in the air.


A tank can climb a wall, provided that the following conditions are met:
1: the tank's center of mass is between the first and last road wheels horizontally, so it won't flip backwards and it's tracks stay on the ground.
2: the tank has enough horsepower to move itself upwards.
3: the tank has enough traction [friction force] not to slide.
The immovable rod machine has 8 tons of force preventing itself from losing traction or rolling over onto it's back, and ideally had enough horsepower courtesy of our wizard to push itself along.

You can prove this to yourself with a loop of scotch tape.


The machine is, however, entirely impractical. By the time you can afford the 5 immovable rods for the track and the 2 additional ones to provide for pitch and yaw, you've spent 17500GP, which is the WBL of a level 7 character, who could fly under her own power at level 5.

[Renduaz]

A tank can climb a wall, provided that the following conditions are met:
1: the tank's center of mass is between the first and last road wheels horizontally, so it won't flip backwards and it's tracks stay on the ground.
2: the tank has enough horsepower to move itself upwards.
3: the tank has enough traction [friction force] not to slide.
The immovable rod machine has 8 tons of force preventing itself from losing traction or rolling over onto it's back, and ideally had enough horsepower courtesy of our wizard to push itself along.

You can prove this to yourself with a loop of scotch tape.

I think that the root of my confusion stems from the fact that OP's treadmill isn't designed like that of an actual tank. Read what I wrote in my post about it not having enough length of treadmill to keep immobile before it needs to make it mobile again.

[LordCdrMilitant]

I think that the root of my confusion stems from the fact that OP's treadmill isn't designed like that of an actual tank. Read what I wrote in my post about it not having enough length of treadmill to keep immobile before it needs to make it mobile again.

That's just how he illustrated it. I don't see anything egregiously wrong with the length of the track. It needs one more rod, though, otherwise it will tip over and fall. Also, he has no source of yaw.

Tanks don't have symmetrical oval tracks to allow for trench crossing and the climbing of small walls. The diagonal portions between the first and last road wheels and the idler wheel and drive sprocket allow it to cross a taller obstacle. It's fairly easy to demonstrate this effect for yourself using a sharpened pencil. You'll notice that if you try to push the pencil over a coin pointy-end first, it goes over easily, but if you try to push it over blunt-end first, it pushes the coin along instead.

The neat thing about the immovable-rod sky-tank is that it's exactly the RAI of the immovable rod [It works RAW, but you have to push the button, since RAW, a creature must spend an action to push the button.] The Tenser's Floating Disk flyer sort of works RAW, [hinging upon the definition of "ground"], but is completely against RAI. However, the sky-tank isn't available until level 7, making it fairly balanced. At level 7, a party could pool their wealth to afford an airship, which is far faster, has more than 8t cargo capacity, and can be a flying base for them.

[Renduaz]

That's just how he illustrated it. It needs one more rod, though, otherwise it will tip over and fall. Also, one of his steering rods is incorrectly oriented. [he has pitch and roll, but no yaw]

Tanks don't have symmetrical oval tracks to allow for trench crossing and the climbing of small walls.

Something still isn't right. As someone else told me, the tank gears move forward on the belt like a car wheels on a road. The belt is basically like a piece of folding road that they take with them. The big wheels ( Idler and the other? ) rotate it and put down a new fold for the driving wheels to drive on perpetually. The belt is higher than the driving wheels, the driving wheels move with traction on the ground..

I don't understand what OP's crank does with the wheel at the bottom and the wheel at the top. Does it just spin them? Does it push the bottom one forward? Are they both turning at the same time when he pulls his crank? I don't get it. http://i.imgur.com/n0l0Pjb.jpg

When I push the crank forward, what actually happens? Does just the wheel the crank is attached to spin? Is that wheel "pushed up" rather than spinned along with the upper wheel? If it's meant to illustrate that the lower wheel spins, thereby pulling down the belt with the active rods while pushing up the segment with the inactive rods to the upper wheel, in order to switch their position, then that doesn't work because both sides are equally stretched over the wheels in the middle. To push up the visible "left" line with the red dots, you have to push down the whole "right" line with the active rods, which can't move.

[LordCdrMilitant]

Something still isn't right. As someone else told me, the tank gears move forward on the belt like a car wheels on a road. The belt is basically like a piece of folding road that they take with them. The big wheels ( Idler and the other? ) rotate it and put down a new fold for the driving wheels to drive on perpetually. The belt is higher than the driving wheels, the driving wheels move with traction on the ground..

I don't understand what OP's crank does with the wheel at the bottom and the wheel at the top. Does it just spin them? Does it push the bottom one forward? Are they both turning at the same time when he pulls his crank? I don't get it.

The crank is how the wizard turns the drive sprocket. Like a bicycle pedal. The uncranked wheel is the idler wheel, free spinning with the track's movement. The cranked wheel would have teeth, to allow it to interface with the track without slippage.

[Renduaz]

The crank is how the wizard turns the drive sprocket. Like a bicycle pedal. The uncranked wheel is the idler wheel, free spinning with the track's movement. The cranked wheel would have teeth, to allow it to interface with the track without slippage.

All I manage to see in his picture is how his track would get stuck when the drive sprocket that he's spinning tries to move it, because such an action would lift up the side with the inactive rods at the same time as it tries to pull down the side with the active rods, which it can't because those rods are active an immovable.. Look at this - http://i.imgur.com/DgSZ8yJ.png Red lines represent rods, black lines represent normal links in the track, and the bottom circle is the drive sprocket while the upper circle is the idler wheel. And when I say replace, I mean replace the next link in position, while the next link gets pulled up with the belt.

Perhaps he'd need to actually "lift up" the two wheels and not just spin them like a tank, but both would have to be the same direction like tank wheels, not the upper wheel with an opposite rotating direction like he pictured it. But then he'd be pushing as much down as he does up so I'm not really sure.

[LordCdrMilitant]

All I manage to see in his picture is how his track would get stuck when the drive sprocket that he's spinning tries to move it, because such an action would lift up the side with the inactive rods at the same time as it tries to pull down the side with the active rods, which it can't because those rods are active an immovable.. Look at this - http://i.imgur.com/DgSZ8yJ.png Red lines represent rods, black lines represent normal links in the track, and the bottom circle is the drive sprocket while the upper circle is the idler wheel. And when I say replace, I mean replace the next link in position, while the next link gets pulled up with the belt.

Perhaps he'd need to actually "lift up" the two wheels and not just spin them like a tank, but both would have to be the same direction like tank wheels, not the upper wheel with an opposite rotating direction like he pictured it. But then he'd be pushing as much down as he does up so I'm not really sure.

His picture shows both wheels rotating clockwise, as they should. Use the right-hand-rule, and you'll find your thumb points the same direction for both wheels.

It works the same way as the tank moving horizontally. Just turn my tank-track gif on its side so the tank is climbing upwards and you'll see it works just fine.

Relative to the drive sprocket, the active rod comes down and the inactive rod goes up. But relative to the active rod, the drive sprocket goes up and the inactive rod goes up twice as fast. The active rod is stationary relative to whatever was chosen as it's reference, and assuming the stationary reference is an object on the planet's surface, the entire machine will go up.

[Zorku]

Okay, first things first. I keep hearing all that jazz about "affixed rods" and the belt yet nobody explains how they are affixed or where which is very important. I look at this picture - http://i.imgur.com/zI0CmAa.jpg , all I see is is a gray loop representing the belt apparently, and circles in the middle representing rods. Forget the active ones for now. Let's talk about the red ones. How are they "affixed" to that belt? Are they on the side to the right, the side to the left, or if the belt is thick enough, somehow inserted through the middle? What affixes them? Right now they're just plain old rods when they're inactive. What keeps them on the belt? Glue? Some kind of strap?
Yes.

I don't see how that's a distinction that would matter. Your 'gear' just needs to be able to roll on the belt. Sew them on with some fishing line for all I care. Given the era I'd expect somebody to glue two strips of tanned hide together with inactive immovable rods in the middle, then sew the ends together with some heavy string. Depending on how much weight you expected on this you might need to use more durable materials.

As for what affixes these rods, look up the magic item "immovable rod." You can turn them on and off (active and inactive,) and while they are active they are fixed in space (relative to... the ground? Blech, let's not get into that.) Hopefully that clears up a lot of confusion.


Secondly, even if I ignored that, how would the device work vertically, "climbing up into the air" as shown by OP in his first image? That would be like trying to make a tank treadmill climb up a vertical wall. Nothing would happen. Gravity would pull the tank down. A tank treadmill can't climb a vertical surface.
Oh boy, maybe I haven't explained it well enough yet.

Let's establish the foundation of this. You've got 4 or more immovable rods, inactive in your pack. You take out one, and activate it in a horizontal position, about as high up off of the ground as you could reasonably climb on top of it (and we'll say that you can easily balance yourself like that.) You pull out another inactive rod and repeat what you did before.

Do you understand how a person effectively creates a ladder/stairs, which they can climb up, via immovable rods?


No, because if you attach any rod to your belt, then that rod can never be activated.
I am completely unaware of any text stating that you can't activate these if something else is tied/glued/affixed to them.


That tank's treadmill is going to get stuck because when it's belt tries to get pulled back up or down "Like a printer", it tugs on the glue which tugs on the trunks and if those trunks are as immovable as an immovable rods, that tank's belt gets stuck,Yeesh you're stubborn.

Let's try and establish another base line: You fell two trees and you affix them to a tank tread (and we will say that there is enough open space in the mechanism that they don't catch against metal when you try to spin the treads.) So, the tank puts along until the first tree makes contact with the ground, yeah? The gear inside the tread keeps going and pretty soon the tank has climbed over the tree.

Now get a stick and go draw some lines in the dirt where the tree is, we'll use those later.

The tank keeps going and the next tree makes contact with the ground, and the tank climbs up over it. Go draw some lines in the dirt for this tree too.

The gear in the tank keeps pushing off of the treads until the tank has moved forward a good ways, and the first tree is about to lift up and swing back round to the front. Notice those lines you drew in the dirt? Huh, tree didn't move during this whole fiasco.

Keep going till the next tree is above to be lifted up. Huh, it's right where the second lines you drew were.

Do you understand what I have described and agree that the tank tread could work like that (again, assuming that the treads have enough space for trees to pass over the top, and without us attaching the tree in a way such that it catches on other parts of the tank when the tread spins)?


Then your belt would require some sort of machinery which decouples one inactive rod from itself when that inactive rod arrives at the same axis as the fixed rods, then fixes it in place, and also a mechanism which couples ( Picks up ) the active rod fixed to the air in the back after deactivating it, so that it's carried by belt instead of just falling down.Yup. These things typically have a button on one end so you can just fix a wedge that depresses the button at the appropriate positions.


I still don't understand how such a treadmill would be able to climb on rods placed vertically, instead of just falling off or never rising up like an actual tank trying to climb a wall or a building.
Would it help if we replaced the tank tread with some chain that's got a bunch of metal hooks hanging off of the outward surface?


Do you know understand Newton's 3rd law of motion ???

He keeps trying to ask how a tank would climb a ladder (I think?)

It's this weird state of missing the forest for the trees while also missing the trees for the forest. Since he never agrees to anything it's hard to even pinpoint how much he understands.


You really should read what I said in my replies before trying to give an explanation. You're just repeating what I already know, and it doesn't work. Honestly I couldn't tell if you knew, and I'm still not convinced that you do.


Suppose that each segment of the track of the tank is an immovable rod, huh? Yes. Yes, I do suppose that, and I do know how a tank works. So let's suppose that. And while on the upper side of the treadmill, they're turned off. Yeah, no problem. And they're turned on while on the lower side, and yes, that fixes your tank into place while in the air.Most reasonable you've been so far.


>Now activate the tank and move it forward.

No, no. NO. NO. NO. NO, and NO.Yes. Move forward (up.) The tank treads that need to remain stationary have got purchase (because in this guy's example they ARE immovable rods,) and the gear inside the tread has got purchase (just needs to jam a tooth on the top side of a rod then push up and do the same thing to the next rod) so just ****ing go forward.



This is why you had to read what I said. When you deactivate the last rod on the bottom of the track, *it* becomes moveable, but the movement of the wheel never lifts it like the belt of an actual tank, which is rolled up and then forward.Yes it does. In this example the rod IS tank tread belt, it IS inactive, and the wheel (gear) forces it to keep moving back relative to the tank, and the shape of the belt redirects that motion until it swings over the top and back into the front.


Your deactivated rod is stuck in place because it's attached to a belt which is attached to immovable rods, which makes that belt unable to roll.No?


A tank's treadmill isn't attached to it's ground. It sits on top of the ground. What you're trying to do would be like drilling a rod into the ground and linking it to the tank's treadmill. It would get stuck.Still no (until it came time to pull the rod out of the ground, but it should be pretty easy to pull an inactive immovable rod out of air.)


If you deactivate one of them, like the last one, the belt can't pull it back to the top, because your deactivated rod is still attached to a segment of the belt which is attached to the active rod ( Front bottom, first rod ).
Are you saying that all items that are touching an immovable rod become fixed in space? I do not think that is part of the item's descriptive text.


The wheels start spinning, attempting to pull the belt up. It tries to pull your deactivated rod along with it. The deactivated rod tugs on the segment of belt in front of it as it's trying to get rolled backwards and up with the belt. That segment of the belt in front tugs on the active immovable rod which is in front of it. And it never moves.This makes it sound like you do not understand how tank tread works.


It will only be able to rotate like an actual tank belt if you deactivated both.No. Don't deactivate both. You just need this flap of belt with an inactive rod to rotate a bit.


Yes I did. It's static, but it isn't attached to the ground. It on top of it. Meanwhile your active immovable rods is static and it's also attached to the belt and *fixed into the air* in one spot that it can't get away from. That would be equivalent of someone pushing a stake through that tank's tread exactly where your active rod is, and lodges that stake into the ground beneath the treadmill.Which is fine, because that's exactly what any segment of tank tread in contact with the ground is like always (or else it slips and fails to move the tank.)


You don't have to answer anymore, but that might work because the bottom tread can slide through my fingers. Moving across one finger and sliding beneath the other. My finger isn't threaded through the depth of the treadmill itself. And, none of that still explains how such a tank would climb in the air vertically. You claim it works just like an actual tank. And an actual tank can't climb over a wall.Tank tread does not slide against the ground.

This might cut to the heart of the matter: When a car's tire spins, to propel the car forward, the part of that tire that is touching the road does not slide against the road (normally. In hazardous conditions this undesirable situation may occur.) The spot that is touching the road has gravity hold it to the pavement, and this section of tire does not move in relation to the road. When the tire lifts back off of the road then it is no longer affixed to the road (by gravity and the static friction between rubber and pavement,) so it moves in other directions.

The deforms somewhat where it comes in contact with the pavement, based on the internal pressure and any debris present, but when it is working correctly it does not slide against the ground.

Do you understand this?


take a tank and a skyscraper's flat vertical wallThere are too many faulty assumptions here. Assume that the sky scraper magnetically pulls the tank against the surface or something.


but I'm asking about the vertical applicationFFS

Do you think this tank with immovable rod tread would be able to function horizontally?


An actual tank can't climb up a wall.You were JUST informed otherwise.


It's too much of a perfectly symmetrical oval, it's not like an actual tank's treadmillIt can be. Simply add those elements. The rest of us find it hard enough to animate this in simplified form.

Ok, step back, what difference do you think the actual shape of standard tank tread makes? Why is it shaped like that? What are the advantages of it?


I don't understand what OP's crank does with the wheel at the bottom and the wheel at the top. Does it just spin them?I'm actually with you on this one. It's a bad way to demonstrate the gears spinning. Would have been better to leave that up to the imagination of the reader.


When I push the crank forward, what actually happens? Does just the wheel the crank is attached to spin? Is that wheel "pushed up" rather than spinned along with the upper wheel?...
Actually, let's go with this. Imagine that I've placed two immovable rods, and I have tied a rope around the bottom one, then the top one, and there is a good portion of the rope above the top rod. Does that rope naturally flop down back towards the ground, and can someone climb it?

Now let's make that better with the bicycle pedals idea. Let's say we've got two or more gears, a tank tread chain with immovable rods sovereign glued to it, and another chain that runs alongside the tread, but this one is longer and it comes down to a little seat with pedals that you can power with your legs (add any number of little free spinning gears you like in order to redirect the chain for the comfort of the pilot.)

If all of the immovable rods are inactive, then you can easily pedal to spin the tread in the air. When one rod is activated, you can use the pedals to lift this machine until the gears would try to move the immovable rod, right? Now go over and turn on a different rod then turn off the first rod. You can climb a few feet higher right?
*Assume that the machine is balanced such that it doesn't try to spin about the single active rod, tearing itself apart.


such an action would lift up the side with the inactive rods at the same time as it tries to pull down the side with the active rods,The side with active rods does not move, despite being pulled on, and the side with inactive rods does move. The chain 'spins' but does not do so freely. The part of the chain that is not free does not move, but the rest of the chain does move, and due to the configuration of the system, the gears climb up the section of chain that is not free.

[LordCdrMilitant]

Consider this question, on the somewhat related topic of abusing RAW:

Can you control the velocity with which you arrive at your location with Teleport?

[Renduaz]

His picture shows both wheels rotating clockwise, as they should. Use the right-hand-rule, and you'll find your thumb points the same direction for both wheels.

It works the same way as the tank moving horizontally. Just turn my tank-track gif on its side so the tank is climbing upwards and you'll see it works just fine.

Relative to the drive sprocket, the active rod comes down and the inactive rod goes up. But relative to the active rod, the drive sprocket goes up and the inactive rod goes up twice as fast. The active rod is stationary relative to whatever was chosen as it's reference, and assuming the stationary reference is an object on the planet's surface, the entire machine will go up.

Oh, yes you're right, they are indeed both in the same direction. But in order in order for the drive sprocket to go up while spinning, instead of just staying in place while spinning ( Which wouldn't work ), then OP's crank would also need to push it straight up, not at a rotation? I know a tank's sprocket moves forward over the ground because of the wheel's shape, rolling over the ground by reducing friction as it spins, but OP's wheel in the vertical position Is basically like a ball inside a sack. It won't roll up the sack on it's own, something has to manually roll it along each step of the way, like taking a basketball and rolling it on the wall with your hand.

Now you said the cranked wheel would need to have teeth, to allow interface without slippage. So I assume it has something to do with that. But now, it seems that vertically, if you look at OP's picture, both wheels are attached to a metal beam, in the middle of which is the yellow rod ( Ignore the fact that it's an immoveable rod for now, it's not what I mean, imagine it's just a normal rod ), on which the pyramid platform is carried. So OP stands on that platform, pulling the crank down trying to push the two wheels and the beam connecting them up through the treadmill, and I'm going to assume it somehow tries moving up instead of just spinning in place because of the teeth on the lower wheel, but while doing so OP is basically cancelling two forces, no?

His feet is on that platform, that platform hangs from what we will call the "Two-wheels beam"., and he's pushing down on the crank so it will lift that up, while his feet are also pushing down on that platform? Isn't that like trying to lift yourself up by the bootstraps, or will he just need enough force to lift his own weight and the two-wheels beam in order to lift it? Isn't he creating more weight when struggles to push down the crank while standing on the platform though?

If not then I think I might finally understand. It would be the addition of teeth to the bottom wheel which you mentioned which really clarify it, since without teeth it looks like it would just rotate in place, grinding against the belt, instead of moving up at the same time it spins.

[tieren]

Think of the treadmill again.

It was a terrible analogy when you brought it up because the whole point of a treadmill is it doesn't go anywhere.

but suppose you picture the treadmill sitting there and its just spinning away. now suppose you could instantly grab the belt on top with perfect grip. One of two things is going to happen, 1) you are going to get flung backwards as the belt keeps moving 2) supposing you are immobile, the treadmill itself will get flung forward.

The sky tank works on principle number 2. when the belt/track is held immobile on one side, the gears keep turning carrying the vehicle forward. When it moves forward enough that your fingers are about to go under the back roller, you release your grip, and at the same instant grip it again at the top front, forcing it to keep moving forward.

It can go up or down or sideways because there is no slippage, its not a wheel turning against a smooth surface it is gear teeth catching on chain (like a bicycle). When the gear turns spinning in place is not an option, it has to move spoke by spoke.

I am fairly certain I could build a working model of this thing (not the flying part but the moving parts) out of legos.

[N810]

LIFTING YOURSELF BY YOUR BOOTSTRAPS FOR DUMMIES.
http://www.instructables.com/id/The-Climbing-Chair/

[Renduaz]

Consider this question, on the somewhat related topic of abusing RAW:

Can you control the velocity with which you arrive at your location with Teleport?

I think the answer is yes. They key word here is "The spell instantly transports you",. If it was even 0.0000001 seconds we could argue about it, but if it's "instant", then for example if you're running or falling while casting it, no time passes between the moment in which the spell is activated and the moment you are in your new destination. Now in order for your velocity to somehow be changed by the magical effect of the spell, the factor which is unknown to us, some measure of time would have to pass between it's casting to your arrival in the new destination. But we are told it's instant.

Then again, "instantly" is a paradox. There's no such a thing in real physics.So we could assume the D&D developers actually mean something like "0.00001 seconds" when they say "instant", in which case I don't even know.

[LordCdrMilitant]

Oh, yes you're right, they are indeed both in the same direction. But in order in order for the drive sprocket to go up while spinning, instead of just staying in place while spinning ( Which wouldn't work ), then OP's crank would also need to push it straight up, not at a rotation? I know a tank's sprocket moves forward over the ground because of the wheel's shape, rolling over the ground by reducing friction as it spins, but OP's wheel in the vertical position Is basically like a ball inside a sack. It won't roll up the sack on it's own, something has to manually roll it along each step of the way, like taking a basketball and rolling it on the wall with your hand.

Now you said the cranked wheel would need to have teeth, to allow interface without slippage. So I assume it has something to do with that. But now, it seems that vertically, if you look at OP's picture, both wheels are attached to a metal beam, in the middle of which is the yellow rod ( Ignore the fact that it's an immoveable rod for now, it's not what I mean, imagine it's just a normal rod ), on which the pyramid platform is carried. So OP stands on that platform, pulling the crank down trying to push the two wheels and the beam connecting them up through the treadmill, and I'm going to assume it somehow tries moving up instead of just spinning in place because of the teeth on the lower wheel, but while doing so OP is basically cancelling two forces, no?

His feet is on that platform, that platform hangs from what we will call the "Two-wheels beam"., and he's pushing down on the crank so it will lift that up, while his feet are also pushing down on that platform? Isn't that like trying to lift yourself up by the bootstraps, or will he just need enough force to lift his own weight and the two-wheels beam in order to lift it? Isn't he creating more weight when struggles to push down the crank while standing on the platform though?

If not then I think I might finally understand. It would be the addition of teeth to the bottom wheel which you mentioned which really clarify it, since without teeth it looks like it would just rotate in place, grinding against the belt, instead of moving up at the same time it spins.

Our enterprising wizard isn't pushing down on the crank, he's rotating the crank to make the gear spin.

Do you know what a rack and pinion system is, and have you ever seen one used in a lift?

The pinion gear interfaces with the rack gear in the same way the driver sprocket interfaces with the vertical chain. It has to go up, because the vertical chain cannot go down, and as the drive sprocket turns, the next tooth must engage the next link. The bar between the idler wheel and the drive sprocket ensures tension in the system, so that the drive sprocket can't escape going up by disengaging from the chain.

Without teeth it may end up grinding upon the belt, depending on how taught the belt is. If the force of friction [which is dependent upon the normal force the belt exerts on the roller, which is a function of how taught the belt it] is high enough, the driver will be able to climb, but that's neither here nor there.

[Renduaz]

Our enterprising wizard isn't pushing down on the crank, he's rotating the crank to make the gear spin.

Do you know what a rack and pinion system is, and have you ever seen one used in a lift?

The pinion gear interfaces with the rack gear in the same way the driver sprocket interfaces with the vertical chain. It has to go up, because the vertical chain cannot go down, and as the drive sprocket turns, the next tooth must engage the next link. The bar between the idler wheel and the drive sprocket ensures tension in the system, so that the drive sprocket can't escape going up by disengaging from the chain.

Without teeth it may end up grinding upon the belt, depending on how taught the belt is. If the force of friction [which is dependent upon the normal force the belt exerts on the roller, which is a function of how taught the belt it] is high enough, the driver will be able to climb, but that's neither here nor there.

I'm not really sure why the wheels can't go down just as much as they can go up apparently, but let's ignore that. Doesn't he still need enough muscle power to lift himself and the wheels at least, as he himself said? When he's trying to rotate the crank, he's trying to spin the gear so that it goes up, but the gear is attached to the other gear and the beam and to the surface the player is standing on. Pushing that gear one tooth up the link is the same weight as pushing the whole contraption, and that would look like his feet would push down on the platform equally as his hands lift up the gears and the beam.

[N810]

No it isn't.
A crank is a rotational lever.
And imparts mechanical advantage.

[LordCdrMilitant]

I think the answer is yes. They key word here is "The spell instantly transports you", key word here being "instantly". If it was even 0.0000001 seconds we could argue about it, but if it's "instant", then for example if you're running or falling while casting it, no time passes between the moment in which the spell is activated and the moment you are in your new destination. Now in order for your velocity to somehow be changed by the magical effect of the spell, the factor which is unknown to us, some measure of time would have to pass between it's casting to your arrival in the new destination. But we are told it's instant.

Then again, "instantly" is a paradox. There's no such a thing in real physics.So we could assume the D&D developers actually mean something like "0.00001 seconds" when they say "instant", in which case I don't even know.

So, now I'm going to be confusing. For the following problem, "Earth" moves in a perfectly circular orbit and its axis of rotation is directly perpendicular to the orbital plane.

We are going to define our first basis as being located at the center of earth, with er pointing directly away from the sun, etheta being tangent to the orbital path in the direction of travel, and ez pointing directly out of the orbital plane. We'll call this Basis 1.

Our enterprising level 13 wizard is standing on the equator on the far side of the planet from the sun. She has a velocity equal to the surface velocity of the planet, in the direction etheta.

http://imageshack.com/a/img923/9029/VyMGDj.png

Here she is illustrated before and after her teleport to the other side of the planet assuming her velocity was kept constant in reference to this basis.

As you can see, she arrives opposite the planet, and is immediately destroyed by air friction, because she's travelling through the atmosphere at almost 1000m/s relative to the surrounding airstream.

Now lets consider a new basis, we'll call it basis 2. It's located at her feet, with er pointing directly away from the center of the earth, etheta being tangent to the earth's surface in the direction of its travel, and ez pointing north parallel to the planet's axis of rotation

http://imageshack.com/a/img922/8444/MPcXXf.png

Now she doesn't instantaneously explode when she teleports on earth's surface. Do you like this definition? It seems fairly RAI.

I don't. Because what if she's teleporting to the North Pole from the Equator. Her angular velocity doesn't change, but her tangential velocity has to change drastically because she's that much closer to the axis of rotation.

So, we can conclude that Teleport is intrinsically smart enough to match her velocity relative to a selected reference in her departing frame to a new selected reference in her visualized arrival frame. Perhaps this is why you have a lower chance of mishap the more familiar you are with your target.

But, she's bored with Earth. And doesn't have to breath. And is fireproof. She wants to visit Io. Teleport has no maximum range. So, she studies Io carefully, mathematically computes where it will be relative to her at any given time, has a clearly defined arrival site, and casts teleport. What stops her interplanetary sightseeing trip? Nothing, according to the previous definition.

Now, leaving Jupiter's sphere of influence and the incendiary hellhole that is Io, think of the ways you can abuse this property.

You can place weapons in orbit and threaten your enemies with threat of high velocity falling object based oblivion! You can build yourself a space castle! You can open a asteroid mining company! More importantly, you can turn your Fantasy campaign into a Sci-Fi campaign! If you thought the ability to do a poor job of replicating a 3rd level spell with a 1st level spell and some loopholes was going to wreck your GM's plan, this will sure as hell do it faster and better.

[LordCdrMilitant]

I'm not really sure why the wheels can't go down just as much as they can go up apparently, but let's ignore that. Doesn't he still need enough muscle power to lift himself and the wheels at least, as he himself said? When he's trying to rotate the crank, he's trying to spin the gear so that it goes up, but the gear is attached to the other gear and the beam and to the surface the player is standing on. Pushing that gear one tooth up the link is the same weight as pushing the whole contraption, and that would look like his feet would push down on the platform equally as his hands lift up the gears and the beam.

If you spun the crank the other way, you would descend just as if you were climbing.

There are already machines in real life that can climb up poles, ropes, etc. like this. The only thing inherently magical about it is the fact that immovable rod allows the rope that its climbing to be affixed to the middle of the sky, instead of to a building or something.

We can do some math here.

Let me prepare some diagrams.

[Zorku]

Oh, yes you're right, they are indeed both in the same direction. But in order in order for the drive sprocket to go up while spinning, instead of just staying in place while spinning ( Which wouldn't work ), then OP's crank would also need to push it straight up, not at a rotation? I know a tank's sprocket moves forward over the ground because of the wheel's shape, rolling over the ground by reducing friction as it spins, but OP's wheel in the vertical position Is basically like a ball inside a sack. It won't roll up the sack on it's own, something has to manually roll it along each step of the way, like taking a basketball and rolling it on the wall with your hand.Again, imagine a ladder, a... railroad, made out of immovable rods (disregard how they got there.) If they are spaced correctly, a gear can follow that path at pretty much any slope, except when gravity is able to pull that gear away from the track, yeah? If you had a nice guide rail that kept the gear pressed against the track, it could move forward even when it was on the underside of the track, yeah?


Now you said the cranked wheel would need to have teeth, to allow interface without slippage. So I assume it has something to do with that.[quote]You've been telling us that you understand how tanks work this entire time without knowing that the gear has teeth?

[quote]But now, it seems that vertically, if you look at OP's picture, both wheels are attached to a metal beam, in the middle of which is the yellow rod ( Ignore the fact that it's an immoveable rod for now, it's not what I mean, imagine it's just a normal rod ), on which the pyramid platform is carried. So OP stands on that platform, pulling the crank down trying to push the two wheels and the beam connecting them up through the treadmill, and I'm going to assume it somehow tries moving up instead of just spinning in place because of the teeth on the lower wheel, but while doing so OP is basically cancelling two forces, no?No. When you turn the gear the teeth tug down on the immovable section (or when horizontal, they push back on the tread that's on the ground,) and those sections do not move, so the vehicle goes up (forward.) The inactive (top) section of chain gets tugged in the other direction, but it is mobile so instead of this moving the body of the machine, it moves the inactive portion of chain.

This is a machine that utilizes the asymmetry of that system in order to perform work. The diagram for a tank on the ground looks the same as for an immovable rod belt sky thing moving vertically up the air.


His feet is on that platform, that platform hangs from what we will call the "Two-wheels beam"., and he's pushing down on the crank so it will lift that up, while his feet are also pushing down on that platform? Isn't that like trying to lift yourself up by the bootstraps, or will he just need enough force to lift his own weight and the two-wheels beam in order to lift it?Looks like you got it with the latter part. It is much the same as an elevator where you have to pull the rope down in order to lift yourself and the elevator platform (and if you utilize the pulleys intelligently you can do so by applying a much lower force over a greater length of rope.)


Isn't he creating more weight when struggles to push down the crank while standing on the platform though?The weight of the system is constant. Simple mechanical elements within the system transform some forces that are applied in some directions into forces applied in different directions.

Take a metal below shoulder height and push down on it. If you are unable to move the bar down, you instead move up.


If not then I think I might finally understand. It would be the addition of teeth to the bottom wheel which you mentioned which really clarify it, since without teeth it looks like it would just rotate in place, grinding against the belt, instead of moving up at the same time it spins.In terms of basic physics you do not need teeth in order to make a comparably smooth roller grip onto a leather belt (and you can replace this with any combination of materials you please.) These things start to slide against each other when you apply a great enough force to overcome the static friction between the materials, which is based on how tightly they are pressed together and exactly how smooth each element is, and possibly with the addition of a fluid (or possibly a powder,) to serve as lubricant.

Using normal world expectations I would expect a polished wooden dowel and a leather belt to slip quite easily, but because these elements were not specified in the original design I have assumed materials with greater friction, or as is the case with a tank, a gear and a chain that fits said gear.


If you spun the crank the other way, you would descend just as if you were climbing.

There are already machines in real life that can climb up poles, ropes, etc. like this. The only thing inherently magical about it is the fact that immovable rod allows the rope that its climbing to be affixed to the middle of the sky, instead of to a building or something.
*Only if our means of clicking the buttons works when the belt moves in the opposite direction. I described a method earlier that would not, but you should be able to design something that would reliably work in both directions.

[Renduaz]

If you spun the crank the other way, you would descend just as if you were climbing.

There are already machines in real life that can climb up poles, ropes, etc. like this. The only thing inherently magical about it is the fact that immovable rod allows the rope that its climbing to be affixed to the middle of the sky, instead of to a building or something.

We can do some math here.

Let me prepare some diagrams.



Again, imagine a ladder, a... railroad, made out of immovable rods (disregard how they got there.) If they are spaced correctly, a gear can follow that path at pretty much any slope, except when gravity is able to pull that gear away from the track, yeah? If you had a nice guide rail that kept the gear pressed against the track, it could move forward even when it was on the underside of the track, yeah?

Now you said the cranked wheel would need to have teeth, to allow interface without slippage. So I assume it has something to do with that. You've been telling us that you understand how tanks work this entire time without knowing that the gear has teeth?

No. When you turn the gear the teeth tug down on the immovable section (or when horizontal, they push back on the tread that's on the ground,) and those sections do not move, so the vehicle goes up (forward.) The inactive (top) section of chain gets tugged in the other direction, but it is mobile so instead of this moving the body of the machine, it moves the inactive portion of chain.

This is a machine that utilizes the asymmetry of that system in order to perform work. The diagram for a tank on the ground looks the same as for an immovable rod belt sky thing moving vertically up the air.

Looks like you got it with the latter part. It is much the same as an elevator where you have to pull the rope down in order to lift yourself and the elevator platform (and if you utilize the pulleys intelligently you can do so by applying a much lower force over a greater length of rope.)

The weight of the system is constant. Simple mechanical elements within the system transform some forces that are applied in some directions into forces applied in different directions.

Take a metal below shoulder height and push down on it. If you are unable to move the bar down, you instead move up.

In terms of basic physics you do not need teeth in order to make a comparably smooth roller grip onto a leather belt (and you can replace this with any combination of materials you please.) These things start to slide against each other when you apply a great enough force to overcome the static friction between the materials, which is based on how tightly they are pressed together and exactly how smooth each element is, and possibly with the addition of a fluid (or possibly a powder,) to serve as lubricant.

Using normal world expectations I would expect a polished wooden dowel and a leather belt to slip quite easily, but because these elements were not specified in the original design I have assumed materials with greater friction, or as is the case with a tank, a gear and a chain that fits said gear.


*Only if our means of clicking the buttons works when the belt moves in the opposite direction. I described a method earlier that would not, but you should be able to design something that would reliably work in both directions.

I said I know how a tank works Zorku, it's just that bottom gear in his image didn't have any teeth and the track wasn't said to have links, he just told me that it would move like a tank, and I didn't know if that entails having those components or that he's suggesting it would move without them like a tank. Anyway, I don't think that I'm able to express my misunderstanding of the crank's pulling motion or the gear "moving up" forward vertically by spinning or some other minor details. I get the big picture of how a tank works, and you keep trying to explain the big picture which I already understand, whereas my problem with the vertical climb is with some things that I believe might be accounted for by some intricacies of the gear's placement on each spacing and link in the rack, which might be what I don't understand in this context. Since I find myself unable to identify what I have trouble imagining through text, I'm just going to assume you're both right and it works perfectly.

[LordCdrMilitant]

http://imageshack.com/a/img924/796/azoZz8.png

I promised math, so here it is:

In this case, the machine is in static equilibrium .

If our wizard pushes harder than the minimum required to remain stationary found in the last equation, she'll cause the crank to turn, and therefore cause the machine to climb its track.

You will notice that this works as long as her crank's length isn't 0.



It doesn't actually work perfectly RAW. This is because an Immovable Rod, RAW, requires a [I]creature to spend an action to activate or deactivate the rod. Thus, it's severely limited in speed to the distance between rods on the tracks, assuming she has a ratchet on the crank so the machine doesn't slip downwards when changing rods. It most certainly work RAI, and as a GM, I would let it work, but because of the way the rules are worded, RAW it's way less practical than just buying yourself an airship with you and your party's combined WBL.

[tieren]

It doesn't actually work perfectly RAW. This is because an Immovable Rod, RAW, requires a creature to spend an action to activate or deactivate the rod. Thus, it's severely limited in speed to the distance between rods on the tracks, assuming she has a ratchet on the crank so the machine doesn't slip downwards when changing rods. It most certainly work RAI, and as a GM, I would let it work, but because of the way the rules are worded, RAW it's way less practical than just buying yourself an airship with you and your party's combined WBL.

Actually it would be a pretty neat way for a necromancer to move around his castle, by having zombies use their actions to activate and deactivate the rods while a couple cranked away.

Maybe to access the top of a tower in his castle or cross a great chasm to the treasure vault. Heck even if the party found it unoccupied it could be a challenge to figure out to work it to access the location. Maybe there are local anti magic fields which occupy much of the space and the clear path through requires very slow and deliberate movements.

He could just fly over or teleport or something, but being hauled over on his super expensive slave driven palanquin could be pretty cool.

[Zorku]

I said I know how a tank works Zorku, it's just that bottom gear in his image didn't have any teeth and the track wasn't said to have links,
If you think that those features are necessary for tank tread to function then you do not understand how a tank works. Having them is better than not having them, but not having them doesn't automatically mean that it will not work, which you would know if you understood how tanks work.

You know what? Give me a thorough explanation of how you think a tank works or else I'm not going to even entertain the idea of treating you like you understand it.


he just told me that it would move like a tank, and I didn't know if that entails having those components or that he's suggesting it would move without them like a tank.If you could form better questions there wouldn't be any confusion there.


Anyway, I don't think that I'm able to express my misunderstanding of the crank's pulling motion or the gear "moving up" forward vertically by spinning or some other minor details.You keep describing force diagrams that don't have much to do with how a tank works.


I get the big picture of how a tank works, and you keep trying to explain the big picture which I already understand, whereas my problem with the vertical climb isHold up: if you understand how a tank works horizontally then you would understand how this works vertically.


with some things that I believe might be accounted for by some intricacies of the gear's placement on each spacing and link in the rack, which might be what I don't understand in this context.I'm gonna breathe for a second.
...

Ok, think back to how long I've been calling it a gear, and how many times you ignored that.
Now think back to how many yes/no questions I have asked about if you understand this part or that part, and how many times you have given direct yes/no answers to them.

These are the heart of the frustration for me.
"I know how a tank works." "Ok, then it goes." "It can't go." "A tank could go." "No it can't." That sort of back and forth doesn't go anywhere, and I've gone above and beyond in my efforts to pin down where our assumptions differ, but you just won't cooperate with that, and I don't know how else to proceed.

So one more time: Do you understand how a gear could climb a ladder?


Since I find myself unable to identify what I have trouble imagining through text, I'm just going to assume you're both right and it works perfectly.Something about that is unsatisfying, but if you're done with this then I won't demand that you stay.