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industrious
2009-07-22, 10:49 AM
So I'm playing this gnome wizard tinkerer, and came up with a (mostly) non-magical idea for a rail gun. I'd start out with a light crossbow(to fool my DM initially and to provide a base to mount it). I'd then forge a metal tube, with the interior wrapped in a coil of silver wire(Craft DC roughly 25), and the two leads would be attached to the end of a wand of shocking grasp, which would replace the crossbow trigger. To activate, load tube with crossbow bolt head, and activate the wand. Would this be allowed? And what kind of damage would it deal? It's hardly a game breaker, but I'm at a low enough level that it could be somewhat devestating.

Indon
2009-07-22, 10:53 AM
Creating a functioning railgun would require very fine craftsmanship of the barrel - I'd probably require more than DC25 for the item to account for the required quality.

Also, when a railgun fires, the barrel becomes superheated. Silver would most assuredly melt, and the crossbow would probably catch fire. I'd allow it, and I'd let it deal pretty good damage compared to a crossbow (probably 2d6, and another d6 fire damage), but it'd be expensive and probably not worth it without the sophisticated technology required to actually maintain a real rail gun.

Edit: Also, the bolts would be more expensive since they'd need to be iron (I believe the standard is wood).

Blackjackg
2009-07-22, 10:53 AM
I probably wouldn't allow it, if only because incorporating pseudo-science into D&D unbalances everything. Not that the crossbow is terribly bad, but it opens the door for all sorts of craziness. I'd say just suck it up and use a refluffed +1 shocking light crossbow.

Hnefi
2009-07-22, 10:58 AM
In real life, the voltage discharged from a Shocking Grasp might be enough to propel a tiny metal object weighing a few grams to a velocity approximately equal to a pea shot from a homemade blowgun. In damage terms, you'd be better off with a BB gun.

In the game, only your DM can say. However, do you even know whether electromagnetic inductance exists in your game world - and does your character?

MickJay
2009-07-22, 11:01 AM
Depends on your DM. One of the reasons nobody makes such things IRL (military, electricity-powered railguns) is that they simply wouldn't work, or wouldn't work nearly as well as a gun (or a real crossbow, for that matter). In best case, the bolt would be provided enough force to fall out of the tube, possibly hitting you in the foot, but all things considered, you'd just waste a charge from the wand. I mean, you can hardly expect to deal more damage at range with that bolt than with the device you want to power it with (and the device itself was already made to deliver the damage; there's the necessary loss of energy on the way).

I'd classify this as a cool idea which is just too impractical to use. I guess that if you used a 10d6 lightning bolt to power the gun, you'd shoot a bolt that could deal 2d6, possibly 3d6 damage at most.

Random832
2009-07-22, 11:03 AM
So I'm playing this gnome wizard tinkerer, and came up with a (mostly) non-magical idea for a rail gun. I'd start out with a light crossbow(to fool my DM initially and to provide a base to mount it). I'd then forge a metal tube, with the interior wrapped in a coil of silver wire(Craft DC roughly 25), and the two leads would be attached to the end of a wand of shocking grasp, which would replace the crossbow trigger. To activate, load tube with crossbow bolt head, and activate the wand. Would this be allowed? And what kind of damage would it deal? It's hardly a game breaker, but I'm at a low enough level that it could be somewhat devestating.

Any plan that starts with "fool my DM initially" is not a good plan - at any point he can say "that doesn't work".

Your wand only has 50 charges, and I wouldn't give it more than 3d4 damage or so - and I'd also give it a very crappy attack roll unless you meet a higher craft DC than you can manage at a level below where you can afford a Wand of CL5 Magic Missile anyway.

No reason it shouldn't work, but nothing like this is described in RAW so it's purely up to your DM - easiest counter is "Shocking Grasp doesn't work that way"

Oh, and [pedant]that's technically a coilgun. For which you really need to be able to energize several different coils in turn. A railgun needs specially designed projectiles and is subject to wearing out and overheating. (on the plus side, it's probably worth higher damage than your coilgun idea)

The other problem is as others have mentioned, to make either design work effectively, you need a lot more current than CL1 Shocking Grasp can give you.

Mr.Moron
2009-07-22, 11:07 AM
Wouldn't a use activated item of Launch Item be better for this sort of thing? It'd be 1,000gp and be able to launch any small object at high/damaging speeds.

quick_comment
2009-07-22, 11:11 AM
Making a railgun is probably a DC80 craft check, and thats after the appropriate research.

And every shot requires a DC 50 reflex save on the part of the weapon or it takes as much damage as the target.

PairO'Dice Lost
2009-07-22, 11:42 AM
Wouldn't a use activated item of Launch Item be better for this sort of thing? It'd be 1,000gp and be able to launch any small object at high/damaging speeds.

A coilgun or railgun would probably require a custom-researched higher-level version of it, but I agree that using a variation on launch item is probably the best approach.

Shinizak
2009-07-22, 11:44 AM
what do you mean "of the non-peasent variety"

Prime32
2009-07-22, 11:44 AM
I came up with an idea for a coilgun for this Eberron party which had a crazy-powerful airship.

Basically, you buy a lightning rail carriage or two, then convert them into a heavily reinforced tube lined with conductor stones. Have a permanent gust of wind blowing through this tube, at as high a strength as you can get. On one end put a custom magical location which can give objects the properties of a conductor stone for 1 round. Place an adamantium sphere inside, sit back and watch.



what do you mean "of the non-peasent variety"A large enough group of commoners who take readied actions can pass a quarterstaff around the world in the time it takes to perform a single action.

Mr.Moron
2009-07-22, 11:49 AM
what do you mean "of the non-peasent variety"

Because the system puts no limit of the number of people in an initiative countdown,and no limit on the total number of actions taken (just the number of actions any one creature takes). You can line up an arbitrarily high number of peasants next to each other, have them pass an item down the line. By the time it reaches the end it has traveled that distance in the space of one round: 6 seconds. Simply do the math and you have the objects speed at the end. Have real-world physics take at the point the last peasant releases the item, and there you have it.

ZeroNumerous
2009-07-22, 11:51 AM
what do you mean "of the non-peasent variety"

Commoner railgun reference.

Heliomance
2009-07-22, 11:53 AM
But why would real-world physics take over when the last one lets go? It simply does 1d6 damage at the end with a 5ft range increment, a -4 non-proficiency penalty and another -4 penalty for throwing something not designed as a thrown weapon. Not really worth it.

Mr.Moron
2009-07-22, 11:55 AM
But why would real-world physics take over when the last one lets go?

Two Reasons:

1) Nobody likes Catgirls.
2) That's just how silly D&D thought experiments like that work.

Random832
2009-07-22, 11:58 AM
Because the system puts no limit of the number of people in an initiative countdown,and no limit on the total number of actions taken (just the number of actions any one creature takes). You can line up an arbitrarily high number of peasants next to each other, have them pass an item down the line.

As Readied actions - that's the important part - without that, you have to line them up in initiative order, which will take forever.

olentu
2009-07-22, 11:59 AM
As Readied actions - that's the important part - without that, you have to line them up in initiative order, which will take forever.

Well you could just have them delay.

AstralFire
2009-07-22, 12:06 PM
But why would real-world physics take over when the last one lets go? It simply does 1d6 damage at the end with a 5ft range increment, a -4 non-proficiency penalty and another -4 penalty for throwing something not designed as a thrown weapon. Not really worth it.

Because silly D&D thought experiments often hinge upon selective adherence to rules of the world versus rules of physics in order to achieve optimal funny.

kc0bbq
2009-07-22, 12:26 PM
I love how the world gets all googly-eyed at the word "railgun". They're not all that special except in really large scale with massive, massive amounts of electricity. :smalltongue:

PairO'Dice Lost
2009-07-22, 12:28 PM
I love how the world gets all googly-eyed at the word "railgun". They're not all that special except in really large scale with massive, massive amounts of electricity. :smalltongue:

Because when people hear "railgun" they automatically think of the really large scale ones with massive, massive amounts of electricity.

AstralFire
2009-07-22, 12:29 PM
I love how the world gets all googly-eyed at the word "railgun". They're not all that special except in really large scale with massive, massive amounts of electricity. :smalltongue:

Massive, massive amounts of electricity, fire, or light always make everything better.

Wild West with swords? Blah.
Pump up the guns with fire, the swords with light, and give some old woman the ability to shoot electricity and HOT DAMN, you've got a worldwide franchise.

The Rose Dragon
2009-07-22, 12:32 PM
Massive, massive amounts of electricity, fire, or light always make everything better.

Wild West with swords? Blah.
Pump up the guns with fire, the swords with light, and give some old woman the ability to shoot electricity and HOT DAMN, you've got a worldwide franchise.

I'm afraid I don't get the reference.

AstralFire
2009-07-22, 12:33 PM
I'm afraid I don't get the reference.

Blasters and Lightsabers and Force Lightning, oh my.

The Rose Dragon
2009-07-22, 12:34 PM
Blasters and Lightsabers and Force Lightning, oh my.

You said old woman. Palpatine only threw lightning when played by a man.

AstralFire
2009-07-22, 12:35 PM
You said old woman. Palpatine only threw lightning when played by a man.

Yeah, I know. I was just trying to be as silly as possible.

Lamech
2009-07-22, 01:49 PM
Shocking grasp gets a bonus against people wearing metal armour. It totally ignores the normal rules for conductivity as normally a giant suit of metal would be a faraday cage and protect the person some. In fact pretty much all DnD magic generated lighting ignore normal conductivity rules.

Which means its up to the DM. I would say no, this does not work, if you were playing a D20 modern game. If you were playing a DnD game I would say, no using science. Otherwise people start nuking stuff with major creation, and everything goes to hell.

AstralFire
2009-07-22, 01:51 PM
Shocking grasp gets a bonus against people wearing metal armour. It totally ignores the normal rules for conductivity as normally a giant suit of metal would be a faraday cage and protect the person some. In fact pretty much all DnD magic generated lighting ignore normal conductivity rules.

Which means its up to the DM. I would say no, this does not work, if you were playing a D20 modern game. If you were playing a DnD game I would say, no using science. Otherwise people start nuking stuff with major creation, and everything goes to hell.

Wouldn't a suit of armor's design make the fact that it's a faraday cage unimportant, as you've now got superhot metal right on your skin? The only issue with it is that it should change to fire damage.

Lamech
2009-07-22, 01:55 PM
Wouldn't a suit of armor's design make the fact that it's a faraday cage unimportant, as you've now got superhot metal right on your skin? The only issue with it is that it should change to fire damage.

It would depend on how much grounded out and how conductive the metal was. I don't know enough about electricity and killing people with it when compared to cooking someone in a suit of armour. The point is normal rules are ignored, even in a case where metal is specifically mentioned. If there was no mention of metal one could argue the game can't include every case, but here metal is included.

Fixer
2009-07-22, 02:04 PM
Wouldn't a suit of armor's design make the fact that it's a faraday cage unimportant, as you've now got superhot metal right on your skin? The only issue with it is that it should change to fire damage.No idiot would wear any sort of metal armor DIRECTLY AGAINST THE SKIN. It would cause severe chaffing. This is the unfortunate reason why chainmail bikinis could never catch on. *sigh*

Most often chain and plate are worn over cloth, perhaps padding, to cushion the blows from bludgeoning weapons as well as they protect against slashing weapons.

DragoonWraith
2009-07-22, 02:05 PM
Wouldn't a suit of armor's design make the fact that it's a faraday cage unimportant, as you've now got superhot metal right on your skin? The only issue with it is that it should change to fire damage.
The more conductive it is, the less hot it's going to get. Conductance = 1/Resistance, the power of the electricity is P = V * I = I2 * R = I2 / G (conductance is G), so higher G means lower P.

Ravens_cry
2009-07-22, 02:08 PM
Wouldn't a suit of armor's design make the fact that it's a faraday cage unimportant, as you've now got superhot metal right on your skin? The only issue with it is that it should change to fire damage.
Actually, in a suit of armour you don't have the metal next your skin. A quilted jacket known as a gambeson (http://en.wikipedia.org/wiki/Gambeson) was worn underneath. Otherwise, youch, chaffing.

daggaz
2009-07-22, 02:19 PM
Well, the physicist in me wouldŽnt let you do it at all.

First, you need to be able to run a current thru the coiled loop, tho I suppose since the wand just blasts free current out anyhow, I could let the grounding mechanism slide...

Then you get stuck on the fact that true rails guns have multiple magnetic loops, not one long coil (we'll get to this later)..

And then you need a MAGNETIC bullet, (thats how real rail guns work),

And finally, you need the magnetic loops to charge at a very precisicely timed sequence in respect to the mass of the bullet, or you get a poor muzzle velocity.


Now you can sidestep a lot of this by just using a highly conductive ring of metal as the bullet, and inducing a current in it with an opposed field, but thats a highschool experiment that doesnt give you any kind of dangerous rail gun at all... just a silly way to shoot a metal loop up in the air, you can catch it in your bare hands..

AstralFire
2009-07-22, 02:37 PM
No idiot would wear any sort of metal armor DIRECTLY AGAINST THE SKIN. It would cause severe chaffing. This is the unfortunate reason why chainmail bikinis could never catch on. *sigh*

Most often chain and plate are worn over cloth, perhaps padding, to cushion the blows from bludgeoning weapons as well as they protect against slashing weapons.

There's no part of armor that directly contacts the skin? I know you wear padding, but I figured there'd be at least some.

Teln
2009-07-22, 02:57 PM
There's no part of armor that directly contacts the skin? I know you wear padding, but I figured there'd be at least some.

Maybe the helmet?

Ravens_cry
2009-07-22, 03:16 PM
Maybe the helmet?
Especially no. While steel is good a stopping blows to the head from sharp objects, not so much blunt force trauma. Paddded cloth in the form of arming caps (http://www.aurorahistoryboutique.com/A000088.htm) provided additional protection, as well as stopping chaffing.

Random832
2009-07-22, 03:25 PM
Right - what we think of a "helmet" today like a motorcycle helmet has padding built in - not so much for medieval armor.

Hnefi
2009-07-22, 03:33 PM
And then you need a MAGNETIC bullet, (thats how real rail guns work),
No. Real railguns use conductive but non-magnetic projectiles.

Ravens_cry
2009-07-22, 03:41 PM
No. Real railguns use conductive but non-magnetic projectiles.
Maybe Daggaz is thinking of coilguns (http://en.wikipedia.org/wiki/Coilgun), also known as Gauss guns.

EleventhHour
2009-07-22, 04:20 PM
Two Reasons:

1) Nobody likes Catgirls.
2) That's just how silly D&D thought experiments like that work.

1) *sniffle*
2) Thus why real physics and D&D should only be mixed very carefully.

Triaxx
2009-07-22, 05:03 PM
Actually, railguns use non-conductive projectiles, and conductive SABOT's.

Any helmet with a nose guard, or cheek pieces touches the skin, or the electricity will arc. Plus it takes the path of least resistance anyway.

DragoonWraith
2009-07-22, 05:08 PM
Maybe Daggaz is thinking of coilguns (http://en.wikipedia.org/wiki/Coilgun), also known as Gauss guns.
Wouldn't change anything. Having an actual magnet for the projectile would either be costly for no benefit, or actually mess things up. I'm not especially inclined to determine which it would be right now.

It does have to be conductive, but that's different.

(or yeah, part of it has to be conductive, the whole thing doesn't have to be. Just need to get a current from one rail to the other)

mistformsquirrl
2009-07-22, 05:12 PM
I'd allow it in the right kind of campaign <^.^>m But then I'm one of those types who'll build battle tanks and the like <. .>;;

That said, you'll need to ask the DM right off the bat, because no matter how well thought out the idea; if the DM says no, it doesn't go.

kc0bbq
2009-07-22, 05:22 PM
I'd allow it in the right kind of campaign <^.^>m But then I'm one of those types who'll build battle tanks and the like <. .>;;

That said, you'll need to ask the DM right off the bat, because no matter how well thought out the idea; if the DM says no, it doesn't go.I'd allow it if the physics worked without metagaming. The OP's physics wouldn't do much and metagame a lot.
:D

Diamondeye
2009-07-22, 06:02 PM
Depends on your DM. One of the reasons nobody makes such things IRL (military, electricity-powered railguns) is that they simply wouldn't work, or wouldn't work nearly as well as a gun (or a real crossbow, for that matter).

BAE Systems is making the Advanced Gun System, which is a railgun, and will be mounted on the DDG-1000 destroyers and the CG(X) when that gets built.

BloodyAngel
2009-07-22, 06:13 PM
Ok... I see these sorts of threads all the time, and while I find them as funny as the next person, I don't think this is gonna work. Most DM's will not let you invent a railgun, no matter how good or bad the physics behind it are. I find the idea of people debating the real world physics of a world where old men wiggle their fingers and fire shoots out to be utterly freaking hilarious.

It's a fantasy game. If you want a device that hurls rapid-fire chunks of stuff like a rail-gun... ask your DM if you can invent some kind of magic item that does it. Like the afore-mentioned "launch bolt" magic item. Trying to bring in real world physics is just going to cause DM wrath, and a hefty smackdown. :smalltongue:

Skorj
2009-07-22, 06:16 PM
BAE Systems is making the Advanced Gun System, which is a railgun, and will be mounted on the DDG-1000 destroyers and the CG(X) when that gets built.

And in 10-20 years we might see one (I say 10 years as I'm reading that destroyers being planned today will be "railgun ready"). The CG(X) design changes completely every few years, it seems. In any case, no military is currently using railguns, and they only make sense if they're hundreds of feet long and have nearly unlimited electric power (e.g., powered by a nuclear reactor), which by some strange coincidence isn't a problem for the Navy. Coil guns are pure SciFi as weapons.

The first railguns deployed will likely be replacements for steam catapults for launching planes off carriers. A railgun does not directly fire any sort of projectile (unike a coil gun), it moves a carriage down a rail. A weapon/plane/etc with no special conductive or magnetic properties can be attached to that carriage.

Set
2009-07-22, 06:31 PM
Combine Launch Bolt with the Book of Eldritch Might cantrip Devlin's Barb (creates one bolt or arrow) and you could make a pretty neat little concealable magic crossbow that creates and fires it's own ammunition.

For a highly magical society, I had the officers wielding maces with three grooves along the half and three-sided wedge-shaped head, in which the wielder could use the Devlin's Barb cantrip (as a free action once per round) to create a bolt, which adhered magically to the side of the mace, and then Launch Bolt as an attack action to hurl the bolt. The mace-wielding officer could then swing away in hand to hand combat, and, when clear for ranged fighting, could conjure up and fire a single bolt each round. If he had time to 'load up' the weapon, he could have up to three bolts readied at a time (three rounds to create them all), but could then launch them as fast as he could normally make ranged attacks (so a 6th level Fighter with Rapid Shot could launch all three in a single round). As a holdover from playing too many arcade shooters, I decided that activating the Devlin's Barb cantrip required the holder to shake the weapon towards the ground momentarily, similarly to the 'shake to reload' option in some arcade shooters.

Higher level officers might have magical bolt-throwers, which create masterwork, silvered or even magical bolts, as well as functioning as magical maces.

The item basically uses a pair of cantrips as it's power source, so it's not terribly expensive, unless one goes for the fancy models that can conjure up special ammunition, or puts further magical enhancements on the weapon, and it creates a distinctive look for the officers of that magical kingdom, who all carry ornate maces with heads reminscent of three-faced pyramids, and don't appear to carry any ranged weapons at all.


If one were to completely ignore the laws of physics, Launch Item combined with Shrink Item would allow one to fling a 'bolt' or 'sling stone' at someone that was really a tree-sized ballista bolt or enormous boulder. But, since the power of those spells don't provide enough 'oomph' to throw enormous boulders or ballista bolts, the items would stop in midair upon resuming their full size, dropping immediately to the ground (as the kinetic energy within the 'sling stone' wouldn't be enough to budge the boulder), making it a useless tactic, unfortunately. Still, using Shrink Item to create bombs is a hoary tradition, and shrinking hundreds of gallons of water into a small metal sphere and leaving it somewhere to explode violently when the water expands to full volume would be effective.


A 'railgun' using Shrink Item compressed gas or fluid (or even a Shrunk spring!) as a propellant would probably work a lot better than messing with Shocking Grasp and the barely-understood (to the medieval / magical mind) forces of magnetism.

Diamondeye
2009-07-22, 07:57 PM
And in 10-20 years we might see one (I say 10 years as I'm reading that destroyers being planned today will be "railgun ready"). The CG(X) design changes completely every few years, it seems. In any case, no military is currently using railguns, and they only make sense if they're hundreds of feet long and have nearly unlimited electric power (e.g., powered by a nuclear reactor), which by some strange coincidence isn't a problem for the Navy. Coil guns are pure SciFi as weapons.

No, the DDG-1000 will be armed with 2 155mm rail guns firing both GPS guided and unguided projectiles. They will not be 100 feet long, although they will obviously require considerable electrical power. The first steel was cut for the first ship this year.


The first railguns deployed will likely be replacements for steam catapults for launching planes off carriers. A railgun does not directly fire any sort of projectile (unike a coil gun), it moves a carriage down a rail. A weapon/plane/etc with no special conductive or magnetic properties can be attached to that carriage.

While that's all dandy, the fact is that the first rail gun will be a naval gun on a destroyer. Here is a video of a test firing

http://www.youtube.com/watch?v=y54aLcC3G74

ericgrau
2009-07-22, 08:43 PM
By conservation of energy the total damage of the bolt is likely to deal less damage than a shocking grasp. Unless piercing is somehow a more efficient method of delivering damage than shocking. Last time I checked: battery powered stun guns "yes", battery powered rail-guns "haha, no it's way too weak". So in fact the damage would be much less than a shocking grasp and probably less than a crossbow.

In general psuedo-science tends to fail. If you yourself have never pulled it off in real life with access to modern technology, and if in fact it turns out to be physically impossible (as it often does), what makes you think your character can do it with less tech?

Or what 2nd poster said: Just don't allow it b/c it screws with the game system.

Random832
2009-07-22, 11:19 PM
While that's all dandy, the fact is that the first rail gun will be a naval gun on a destroyer. Here is a video of a test firing

More to the point, the linear motors they are making to replace steam catapults are not, in fact, railguns. So many people use "railgun" as a generic term for any kind of linear motor or mass driver.

Callista
2009-07-22, 11:21 PM
I think it is a great idea. It really just needs stats of some other weapon of equivalent crafting requirement and cost, and it'll fit in just fine. It sounds exactly like something a gnome might make.

Skorj
2009-07-23, 12:11 AM
No, the DDG-1000 will be armed with 2 155mm rail guns firing both GPS guided and unguided projectiles. They will not be 100 feet long, although they will obviously require considerable electrical power. The first steel was cut for the first ship this year.



While that's all dandy, the fact is that the first rail gun will be a naval gun on a destroyer. Here is a video of a test firing

http://www.youtube.com/watch?v=y54aLcC3G74

Sorry to contradict, but you've been misinformed the guns you describe aren't railguns. Here's a reasonably official document (http://fas.org/sgp/crs/weapons/RL32109.pdf) (PDF warning) from the FAS site if you don't want to believe Wikipedia. It will be armed with the 155mm Advanced Gun System (http://en.wikipedia.org/wiki/Advanced_Gun_System) which is a odd gun/rocket combo with very long range, not a railgun. It is, as I said, "railgun ready", with a bunch of electrical power available, but no actual railgun.


The 155mm guns on the DDG-1000 could be replaced in the future with an electromagnetic rail
gun or directed-energy weapon. The DDG-51 does not have enough electrical power to support
such weapons.

Thus my estimate that we might see railguns in just 10 years, not 20. Or we might not, if the Navy decides to go the energy weapon route (which IMO would be silly, as what use is a naval weapon that's not over-the-horizon?).

lvl 1 fighter
2009-07-23, 01:01 AM
Rail Gun? (http://www.youtube.com/watch?v=4CNldTbYy5A&feature=related)

Lamech
2009-07-23, 02:45 AM
But, since the power of those spells don't provide enough 'oomph' to throw enormous boulders or ballista bolts, the items would stop in midair upon resuming their full size, dropping immediately to the ground (as the kinetic energy within the 'sling stone' wouldn't be enough to budge the boulder), making it a useless tactic, unfortunately. Umm... okay lets say we have a boulder and we shrink it. So you arbitrarely pick a reference point that makes everything work out nicely ignore the fact that you can't really do that. What if we compared it to the sun? I think then conserving energy would create deadly bullets when something was shrunk. Also why are we arbitrarily picking energy and breaking conservation of momentum? I'm sorry but your logic doesn't stack up. Its obviously up to the DM to interpret what happens. (Which has the same result but lets ignore that.)




A 'railgun' using Shrink Item compressed gas or fluid (or even a Shrunk spring!) as a propellant would probably work a lot better than messing with Shocking Grasp and the barely-understood (to the medieval / magical mind) forces of magnetism. Thats actually really clever. Magically propelled guns. Pretty much exaclty like our guns except they use magic to provide the charge. Clever. Still clear it with the DM because he might get annoyed at SCIENCE!

HamsterOfTheGod
2009-07-23, 05:23 PM
Oh there's nothing wrong with science.

If you want to refluff a wand of shocking grasp as a "TASER", that's fine.

If you want to say that by expending a charge from a wand of shocking grasp you can fire a bolt from your "rail gun", that's fine.

But if you want to say that by expending a charge from a wand of shocking, you can do more damage than you could by using shocking grasp or something other 1st level spell cast with the same caster level, than that's a problem.

A "rail gun" that shoots a bullet-like projectile that has a range increment of say 100 ft increment and does 1d4 damage per caster level (max 5d4), sounds fair.

Diamondeye
2009-07-23, 07:07 PM
Sorry to contradict, but you've been misinformed the guns you describe aren't railguns. Here's a reasonably official document (http://fas.org/sgp/crs/weapons/RL32109.pdf) (PDF warning) from the FAS site if you don't want to believe Wikipedia. It will be armed with the 155mm Advanced Gun System (http://en.wikipedia.org/wiki/Advanced_Gun_System) which is a odd gun/rocket combo with very long range, not a railgun. It is, as I said, "railgun ready", with a bunch of electrical power available, but no actual railgun.

No, I haven't been misinformed, I jsut wasn't specific enough. I should have said the DDG-1000 will eventually be armed with railguns (which it will). The gun in the video is definitely a railgun.


Thus my estimate that we might see railguns in just 10 years, not 20. Or we might not, if the Navy decides to go the energy weapon route (which IMO would be silly, as what use is a naval weapon that's not over-the-horizon?).

You are correct; there is no good reason to use a directed-energy weapon since it can only shoot in direct fire. That would severely limit its usefulness for naval gunfire support.

It's not "might" at all, however, the railgun will definitely be on naval ships in less than 2 decades and not for launching aircraft.

Skorj
2009-07-23, 07:35 PM
...
It's not "might" at all, however, the railgun will definitely be on naval ships in less than 2 decades and not for launching aircraft.

Well, worthier ideas have been cancelled by congress because they're built in the wrong team's district. I've been preaching railgun battleships for decades now, so I certainly hope to see them, but really those AGS guns provide a remarkable rate of fire out to a remarkable range, so a railgun would need to be quite impressive to replace them.

I'm hoping the directed energy weaopns would be for missile defense, not offense, as a horizon limit is fine for that. At some point though there's no difference between your radar system and a directed enegy weapon. The (30+ MW) aegis-replacement system hardly needs to connect to any (other) weapon to destroy swarms of incoming missiles!

industrious
2009-07-23, 08:57 PM
...He allowed it. Here's the stats:

Range 50ft
3d4 damage, type piercing
x3 critical
takes full-round action to reload
requires Exotic Weapon Proficiency(Rail Gun)

Must roll separate d20 each time fired; on a roll of 2, or 3 will collapse, requiring a Craft(weaponsmithing) check to repair it, DC equal to my attack roll. A natural 1 causes the wires of the wand to come loose; in addition to requiring repair, I get 5d6 electricity damage.

Not too shabby, though, for a level 2 wizard.

HamsterOfTheGod
2009-07-23, 09:18 PM
...He allowed it. Here's the stats:

Range 50ft
3d4 damage, type piercing
x3 critical
takes full-round action to reload
requires Exotic Weapon Proficiency(Rail Gun)

Must roll separate d20 each time fired; on a roll of 2, or 3 will collapse, requiring a Craft(weaponsmithing) check to repair it, DC equal to my attack roll. A natural 1 causes the wires of the wand to come loose; in addition to requiring repair, I get 5d6 electricity damage.

Not too shabby, though, for a level 2 wizard.

Flavorwise it's good. Otherwise it's a little better than a heavy coossbow (1d10) but much more expensive (feat and costs).

Set
2009-07-23, 09:29 PM
Umm... okay lets say we have a boulder and we shrink it. So you arbitrarely pick a reference point that makes everything work out nicely ignore the fact that you can't really do that.

No, the spell arbitrarily broke a law of physics, conservation of mass.

I just don't assume that one specific break means that every single thing falls down and the heavens break open and starting raining down kittens. If a 1/1 lb item is hurled by a spell that can't hurl anything that weighs more than a 1/2 lb anyway, when the item swells up into a 320 lb boulder, it's still only gonna have 1/2 lb of 'thrust' from that cantrip-level spell, which is not gonna move that 320 lb boulder very far at all (and the DM would not be out of line to deny even that 1/2 lb of thrust and rule that the Launch Bolt / Item spell just flat out laughs in your face and fails when faced with a suddenly-320-lb bit of ammunition).

Still, the other idea for Shrink Item powered guns (shrunken gas/liquid accelerants or shrunken springs or even solid items that slam into the 'ammunition' and send it flying) would work fine. Fill a metal or stone tube with a shrunken metal cylinder, then put the item to be hurled in front of said cylinder, and when the cylinder expands instantaneously to full size, it's going to slam into the 'ammunition' and propel it violently out the open end of the tube. Face said end towards the enemy before un-shrinking the 'propellant' cylinder, and you've got something that launches ammo like a catapult, but lies flat on it's side like a cannon. Shrink Item can also be made permanant, and the item can be shrunk and un-shrunk on command. Speak the command word again on the next round, load in some new ammunition, and you're ready to launch another missile. A seige commander with access to this sort of magic might as well get a permanant Shrink Item put on the metal cylinder 'cannon' as well, for ease of transport into the war zone...

Just don't get the command words mixed up. Enlarging the cylinder while the cannon itself is still shrunk will probably explode it from within, and wreck a valuable piece of equipment!

Diamondeye
2009-07-23, 09:51 PM
Well, worthier ideas have been cancelled by congress because they're built in the wrong team's district. I've been preaching railgun battleships for decades now, so I certainly hope to see them, but really those AGS guns provide a remarkable rate of fire out to a remarkable range, so a railgun would need to be quite impressive to replace them.

Any railgun will have at least twice the range, possibly 3 or 4 times the range. Range is more important than rate of fire; all the rate of fire in the world is no help if you can't reach the target, and greater range gives you a lot more ocean to hide in while shooting.

Railgun "battleships" at least, as in some sort of WW-II-like armored ship with a massive main battery of very large railguns is exceedingly unlikely ever to exist, at least in any oceangoing navy. Predictions of whether it might appear in space would be sheer speculation at this point; no one can give odds either way. Massive armored ships can only be in one place at one time; it makes more sense in the modern world to build aircraft carriers and large numbers of destroyers; aircraft can do things ships can't and destroyers can be in more places at once - especially given the fact that every ship must be in port for maintenance at times. Destroyers can be in more places doing more things, and while in certain specific situations a "battleship" might be very useful, most of the time it simply wouldn't be advantageous. Hunting pirates, for example, is much better accomplished with 20 destroyers than 2 battleships. The other problem with large armored ships is that effective protection against modern shape-charged warhead ASMs would be prohibitively heavy and expensive and detract from the armament the ship could carry significantly. Besides, things like antennas can't be armored, so mission-killing such a ship would still take it out of action, even if it wasn't easily sunk.

Now if by "rail-gun battleship" you mean something simply carrying larger numbers of railguns rather than missiles for offensive weaponry, that's a good idea since projectiles, even guided ones, are cheaper and can be carried in larger numebrs compared to missiles.


I'm hoping the directed energy weaopns would be for missile defense, not offense, as a horizon limit is fine for that. At some point though there's no difference between your radar system and a directed enegy weapon. The (30+ MW) aegis-replacement system hardly needs to connect to any (other) weapon to destroy swarms of incoming missiles!

That's a serious exaggeration of the ability of radar to damage electronics.

Skorj
2009-07-23, 10:20 PM
Now if by "rail-gun battleship" you mean something simply carrying larger numbers of railguns rather than missiles for offensive weaponry, that's a good idea since projectiles, even guided ones, are cheaper and can be carried in larger numebrs compared to missiles.

That's a serious exaggeration of the ability of radar to damage electronics.

20 years ago you needed a 1000 feet of rail and a nuclear plant to have a chance at making a railgun work. We had a spare battleship becoming a museum 20 years ago, so that made sense. :smallsmile:

Well, urban legends abound in the military, but I've spoken with folks who were quite sure that the Aegis system could zorch both missiles and planes quite rapidly, by simply turning the dwell up. IIRC that system projects over 7 MW of power in a tight beam, so focused on one target that's an extrordinary amount of power. Of course the radar's not doing it's actual job if it's doing that. The replacement radar is supposed to be in the 30 MW range, which is a ridiculous amount of power. There's been some discussion about using that against UAVs recently on military forums, but shielding specifically against a known radar system seems reasonable (and, again, war stories ... might all be entirely BS).

industrious
2009-07-23, 11:17 PM
I'm not the one using the gun, though. One of the other PCs, a rouge is, and it does give our party an initial advantage, since instead of waiting for sneak attacks with daggers, the two of us stay back and blast (I'm an evoker) while the cleric and paladin go into melee. Thank God for Use Magic Device.

Kylarra
2009-07-23, 11:30 PM
I'm not the one using the gun, though. One of the other PCs, a rouge is, and it does give our party an initial advantage, since instead of waiting for sneak attacks with daggers, the two of us stay back and blast (I'm an evoker) while the cleric and paladin go into melee. Thank God for Use Magic Device.Seems like a rather underpowered option for a rogue tbh.

industrious
2009-07-24, 12:36 AM
Even one at 2nd level? We're currently in a beseiged city, defending the walls from a horde of invading orcs. Scouting and sneaking aren't the most useful tools right now.

Worira
2009-07-24, 12:43 AM
Yes. You'd be better off with a hand crossbow. Or a regular crossbow.

Kylarra
2009-07-24, 12:48 AM
You're burning a feat and a charge from a level 1 wand (15gp/shot), for the ability to do on average 2 more damage (3*2.5=7.5) than a heavy crossbow (1D10 = 5.5 average) at a significantly lower range (50' range increments vs 120' for heavy and 80' for light), a 10% chance of "fumbling" and a 5% chance of killing you outright. 5D6 averages out to 5*3.5 = 17.5 damage, more than enough to drop a rogue with anything less than a 16 con and a maxed out hp roll.

Additionally, if your rogue has even a +1 strength modifier, over 2 rounds the shortbow will outperform that weapon (2d6+2 averages out to 11 damage over 2 rounds, whereas your "railgun" can only fire every other round, or costs another feat if your DM is generous and allows Rapid Reload to be chosen for it).

edit: sort of ninja'd

Leon
2009-07-24, 01:48 AM
(to fool my DM initially

Never good, its best to work with your DM when creating things

On the topic Rail Gun (http://www.warbirdphotographs.com/ATC/ATC-GermanRailGun-1.jpg)

Roderick_BR
2009-07-24, 10:24 AM
And your DM could easily screw you, saying that when you activate the charge, it is used up... and that's it. The bolt hits the target without any extra damage other than the base one.