Cool Idea I Had, Need Help With Details

[Sikening]

Hey, so I was wondering if there's any science-buffs that would be able to help me with this. I remember being taught that magnets use positive and negative charges to attract and repel metal. I also remember something like lightning occurs when there's a buildup of positive charges (or something like that, I actually don't remember all of it).

So basically, I want to use an electric spell, or storm + another spell, to generate a magnetic field in my campaign, but I don't know all the little details. Because let's face it; I nearly failed grade 10 science.

So the idea is bad guy #1 casts a spell that interferes with the climate and created a magnetic field that pulls characters in armor and metal weapons to the ground.

What I need: How this would be done.

If anyone can help, that would be greatly appreciated.

[Sith_Happens]

Well, to get started, you'll need a sacrificial altar, a good Knowledge(Religion) check, and a lot of catfolk. Preferably female.

[Deophaun]

Ghorus Toth's magnetism from Unapproachable East. Sixth-level Sorcerer/Wizard spell.

Beats the heck out of sacrificing catfolk. The blood and hair is just too much of a mess to deal with.

[Nettlekid]

It's technically possible, but because we have no idea what the charge of a Lightning Bolt spell is, or the voltage difference across a Wizard, or anything, then it's basically impossible to tell you what you'd have to do to make it work.

After all, electricity attacks in fiction are notorious for not working the same way that electricity works in real life. It's just absolutely wrong.

Instead, you might like to look into such spells as Magnetism (Wu Jen 3, perhaps you could Chain it), Ghorus Toth's Magnetism (Sor/Wiz 6, sounds a lot like what you want), and the Lodestone Marauder from MM IV.

EDIT: Oops, Swordsaged on one point by not reading the non-blue text in the post above. XD

[Mr. Mason]

Well... Yes, it is possible, But probably more of an epic magic thing. The way I'm picturing it, you would be directly affecting a large portion of the earth's magnetism -- which would have lots of nasty consequences.

If all you want is a spell to bring them to the ground, the seventh level wizard/sorcerer spell "Reverse Gravity" could be refitted to suffice. Maybe more of an "Dominate Gravity" just use the spells duration and targeting info with some fluff about the weather, tack on a dc applicable to the level of the party and just how many of your playthings, *ahem* Players, you want to see on the ground begging for their miserable lives. Maybe just use the dc for an appropriate battlefield control spell, such as Entangle cast by a druid one level higher than your average party members level. I would think this kind of spell targets Fortitude.

Hope this helps!

[PraxisVetli]

You might want to look at a slightly modified version of Druid's Repel Metal.

[buttcyst]

or just use a bunch of telekinesis

[Deophaun]

You could also make a custom spell that merges something like orb of electricity/lightning bolt and Evard's black tentacles. Single target for the lightning part, make it an evocation with a Reflex save. Afterwards you have a 20-ft. emanation centered on the target that grapples people in metal armor. Similar strength to EBT, but no damage. Might still be a 4th level spell.

[Sikening]

These are some pretty solid ideas, but the one thing I'm trying to achieve this way is a certain level of badass. I want the party to know that if they tango, they're screwed. It's just a story encounter that's not supposed to be an actual fight (more final boss-ish, but met about 1/4 way through). So level doesn't matter in terms of epic-ness, I just want the badass factor.

Which is why I'm trying to figure out if there was some way it could work.

If anyone knows their science, can you think of anything? Let's assume the lightning in D&D works the same as the lightning in real life, and that the target and caster are emitting the charges needed for it to strike.

[Urpriest]

Ok, so you're trying to make an electromagnet with an electrical spell, and assuming that the Lightning Bolt spell works like a real lightning bolt?

The magnetic field of a current along a straight line is B=2*10^-7 T m/A * I/r, where I is the current and r is the distance from the wire, while the other symbols are for units. According to Wikipedia, an average lightning bolt carries 30,000 amperes of current, so if it were precisely linear its magnetic field would be 0.006 Teslas divided by the number of meters of distance between the target and the bolt. That field pushes in a circle around the bolt, by the way, so for the situation displayed here:

A
Caster Target
B

A would be drawn upwards while B would be drawn downwards.

How powerful is this field? I have to go now, so I'll leave that to the next person who wants to take a crack at it.

[Segev]

First off, a warning: If you do this, the players will look into replicating it. So establishing this as a law of physics in your setting will likely mean it comes back again and again.

Secondly: The actual science is that moving electric fields induce magnetic fields, and vice-versa. Yes, this can be self-propagating (this is, in fact, how the wave-theory of light works). It's called "electromagnetic waves."

Electro-magnets, which is what you're looking at emulating, work by wrapping a coil of wire such that electrical current flows in circles around it.

But let me start a little more basically: When a current flows through a wire, the electricity is moving in a straight line. Around the wire, a circular magnetic field forms, responding to the electrical current. Wrap this wire into a loop, and the field lines wrapping around the wire "pile up," making something akin to those circular magnets you often find in magnet kits (the black ones with holes in the middle); the top and bottom of the donut are the north and south poles of this simple electromagnet.

Stack a number of loops together, and they form a sort of artificial bar magnet. Wrap them (with insulation) around a piece of ferrous metal, and that reinforces the magnetic field running down the middle to make a fairly strong electromagnet.



Thus, for your "badass special effect," what you probably want is to have the caster(s) trying to throw around lightning, and have whatever meteorological effects and other magic and conflicts between the casters' electric spells cause the lightning to loop back upon itself and spiral up, around and around, and HANG there. Possibly coiling like some great blue-white serpent.

Within the center of this massive coil of naked but magically generated/bound/shaped electricity will be a magnetic field, like a giant invisible, intangible bar magnet. Have that do whatever you like with the metal objects in the area. I suggest a tornado of metal sucked to the middle and whipped about by the ozone-winds. Have them arrange themselves like iron filings on a page over a bar magnet, but suspended in the air, and then let gravity finally yank them down to stick them to the ground in a ring around this coil for as long as the coil is fed by electro-magical forces.

[Nettlekid]

These are some pretty solid ideas, but the one thing I'm trying to achieve this way is a certain level of badass. I want the party to know that if they tango, they're screwed. It's just a story encounter that's not supposed to be an actual fight (more final boss-ish, but met about 1/4 way through). So level doesn't matter in terms of epic-ness, I just want the badass factor.

Which is why I'm trying to figure out if there was some way it could work.

If anyone knows their science, can you think of anything? Let's assume the lightning in D&D works the same as the lightning in real life, and that the target and caster are emitting the charges needed for it to strike.

Oooh, now, there's your first problem. You're expecting your team of adventurers to back down from a fight that seems too strong. I promise you they won't. You'd find a plucky level 5 party who will try to take on a dragon, probably fail pretty miserably, and instead of running home to lick their wounds, regrouping and trying to out-tactic the dragon. They're suicidal, but they're brave. They will not be cowed by a show of magnetism.

Secondly, looking at your original suggestion, if you're trying to do it by the laws of physics (which honestly, you're already using magic, you shouldn't be worrying about physics), you're going to have a tough time forcing them to the ground. In order to use electricity to make a magnetic force, you have to run current through a wire or something. The important thing is that the current is moving, because nonmoving charges (I was about to say static charge, but realized that might be confusing) do not have a magnetic field and do not interact with magnetic fields. (Make sure you aren't confusing ferromagnetism with electromagnetism. Ferromagnetism works with the arrangement of charges in the structure of a ferrous object, while electromagnetism works as I'm about to describe, with currents in wires.) In a straight wire, the charges moves straight, and the magnetic field is a loop around the wire. You can determine the direction of the loop with the right-hand-rule: If you point your thumb in the direction of the current (which is the opposite direction of the direction the electrons are going (thanks a bunch Ben Franklin for getting it the wrong way 'round)) the direction that your fingers are curling in is the direction of the magnetic field. Any charged particle, like some random proton shot into the area, will have its own loop around it, and based on how the two loops overlap, a force will be exerted on the particle and it'll be pushed into some direction. You can observe this if you have two wires in parallel, because their magnetic fields will interact and the wires will move (away from each other if the currents are antiparallel, together if the currents are running in the same direction (because if you do the right hand rule, you can see that in the area between both wires, one wire's field is pointing up, and the other wire's field is pointing down, and opposite charges attract.))

This isn't all that useful to you, since it'll depend on where the party is in relation to the wire. Instead, as most physicists use when they want a constant magnetic field, you'd want a large circle of wire, perhaps in the air or running under the ground. Current still flows through in the same way, and the magnetic field still makes a ring around the wire, but because of the shape of the wire the shape of those "rings" of magnetic field instead points in a constant direction through the loop. A different right-hand-rule can tell you the direction: if you curl your fingers in the direction of the current (again, opposite as the direction of the flowing electrons), your thumb points in the direction of the magnetic field. So if your wire is underground, and you strike the lightning bolt so that the lightning travels clockwise, the current is travelling counterclockwise and the magnetic field is pointing up. Do it the other way around and the magnetic field will point down. Keep in mind, you'll need a consistent flow of electricity for it to work; one burst will have a small effect and then nothing. You'll need something continually discharging, like Pikachu. A Spell Trap probably won't work, since it'll do a burst every six seconds. You need a constant supply.

However, this will do nothing if the party is A) Uncharged and/or B) Stands still. Let's start with B, because as I said above, electromagnetic fields have no effect on nonmoving charges. All you'll need to do is get them to charge you and they'll feel a force, but if you plow them into the ground, stopping them from moving, then no force will be on them. So...That's a bit tricky to handle. Also, they will have to be charged. They are made out of protons and electrons, but as those have equal and opposite charges, the forces they feel will balance out and they basically count as neutral. You'll need to somehow fill them with an excess of electrons or drain the electrons from them in order to charge them, much like the way you either fill or drain a glass rod with/of electrons when you rub either fur or silk. Simply zapping them won't do the trick, the whole point of zapping hurting is that it's electrons flowing through, not staying. Rubbing a balloon on your head is the charging, a static shock is going back to normal. I can't think of any spells that produce such a charge effect. Orb of Electricity's Entangling effect is probably the closest thing in D&D terms. And like that effect lasts only one round, they'll lose their charge quickly because the ground they're standing on with compensate, adding or removing electrons as needed. So you'd probably want to either insulate them somehow (plastic/rubber/glass ground? A bit fanciful) or continually charge them, and I don't know how you would do that.

Now, the direction of the magnetic field is NOT the direction that the party will feel a force in. There's a third right-hand-rule, which states that if you point your middle finger in the direction of the magnetic field, and your index finger in the direction of the "current" of the particle moving in the field (in this case, the direction the the adventurers are moving if you somehow drained them of electrons, leaving them positively charged, or the opposite of that if you filled them with the electrons, leaving them negatively charged), then your thumb will point in the direction that they'll feel a force in. So, if you have a big ring underground creating a magnetic force pointed up, and you positively charged your adventurers, then as they run toward you (assuming you're straight ahead of them) they will feel a force pushing them to the right. In order to get them to be pushed into the ground, you'd have to set up your giant wire ring above ground (or like half above, half below) vertically, so that the magnetic field was in a direction to their left (so either run current through the ring counterclockwise and put the ring to their left, or run current through the ring clockwise and put it on their right. Remember, that means have the lightning travel in the opposite direction). Which isn't exactly stylish. If you negatively charged them instead, you'll have to reverse the clockwise-counterclockwise directions I just told you.

But all of this is kind of moot, because the forces involved are very small. A bolt of lightning consists of a current of (-)30,000 Amps, which is a lotta lot. For comparison, you have a bit more than half an amp in a regular light bulb. The magnetic field of a loop of, oh, 10 meter radius with that current running through it (and let's ignore the fact that the wire would definitely burn up from this, because we're using magic wire. We'll also ignore its resistance, or assume that the spellcaster can create a voltage difference so that the voltage of the caster divided by the resistance of the wire makes 30,000 Amps. We'll also ignore the fact that this is impossible, because of course, magic) would be a little less than 2 milliTeslas. Assuming they're like right next to it. They wouldn't be, and so it would be much smaller than that. If the loop was bigger, it would be even smaller. Those 2 milliTeslas mean that they experience a force equal to 0.002 T times their velocity times their charge. I'll assume 30 ft/round movement speed, so if they moved double that in a charge (ooh, bad word to use here, uhh, full-round-action-where-they-double-move-and-then-attack) that's a speed of 60 ft/6 seconds, 10 ft/s, or about 3 m/s. So the force they feel is 0.006*their charge. In order to pin them to the ground, you'd need a force like three times as strong as gravity (assuming the adventurer weighs about 150 kg with all their gear and stuff, they push against the earth (assuming the Material Plane's gravity is the same as ours) with ~1500 Newtons), or 4500 Newtons, which you'd get with a charge of 750000 C. That's akin to the collective charge of 37500 balloons rubbed on your head, all at once.

This would all work quite a bit differently in practice as compared to how I've stated it out here, because things aren't as easily estimated as I've described them to be, and I'm not sure how to interact with the adventurers' distance from the ring, but I think this quite clearly suggests that your idea won't work the way you want it to. Seriously, just use one of the many gravity-altering spells in existence.

The Outer Planes swell as the souls of billions of catgirls take their place as new petitioners. Somewhere, I get a wickedly high number of Dark Craft points for their sacrifice.

[Xervous]

Random Encounter: Wall of Text

Make a will save, you die.


In all seriousness though, great read. Some of my associates say that a large quantity of those souls are being put to good use.:xykon:

[Mr. Mason]

Actually, a fairly weak wizard would be capable of doing this -- if he utilized a tesla coil. A Tesla coil is capable of amplifying small amounts of electricity into gargantuan amounts.
"The most popular of his designs is made up of a transformer, capacitor, spark gap, main coil, minor coil and discharge sphere. Here is how it works: The transformer receives a charge of about 100 volts from an outside source and increases it to as many as 50,000 volts or more. The capacitor stores the voltage until it reaches its limit, at which point the spark gap emits all of the pent-up energy in one massive outburst, surging to the main coil, which is often built out of wide copper wire, generating a powerful magnetic field. The current continues to the minor coil that serves as a transformer, utilizing the effects of the magnetic field to build enormous quantities of voltage." (National High Magnetic Field Laboratory)

So even a commoner could cause this. You know how sometimes when you touch someone? This is electricity, and even this small amount could potentially do this -- given a Tesla coil designed to do this.

So, depending on how you describe it and how knowledgeable your players are, they might not be impressed.

If you do want to impress them, you could employ a Sephiroth tactic. Just pull a meteor of course and aim it at a kingdom. This wouldn't be difficult to do either. A few divinations, a conjuration spell, (or maybe even a Bigby's ____ Hand) and there you go! It would still be a powerful feat!

After binding them to the ground with magnetism, just make the watch as you send a meteor to the king. This is a whole lot more impressive -- to me, at least. I'm not sure if that fits into your campaign, though.

I really do hope this helps!

[Nettlekid]

Actually, a fairly weak wizard would be capable of doing this -- if he utilized a tesla coil. A Tesla coil is capable of amplifying small amounts of electricity into gargantuan amounts.
"The most popular of his designs is made up of a transformer, capacitor, spark gap, main coil, minor coil and discharge sphere. Here is how it works: The transformer receives a charge of about 100 volts from an outside source and increases it to as many as 50,000 volts or more. The capacitor stores the voltage until it reaches its limit, at which point the spark gap emits all of the pent-up energy in one massive outburst, surging to the main coil, which is often built out of wide copper wire, generating a powerful magnetic field. The current continues to the minor coil that serves as a transformer, utilizing the effects of the magnetic field to build enormous quantities of voltage." (National High Magnetic Field Laboratory)

So even a commoner could cause this. You know how sometimes when you touch someone? This is electricity, and even this small amount could potentially do this -- given a Tesla coil designed to do this.

So, depending on how you describe it and how knowledgeable your players are, they might not be impressed.

If you do want to impress them, you could employ a Sephiroth tactic. Just pull a meteor of course and aim it at a kingdom. This wouldn't be difficult to do either. A few divinations, a conjuration spell, (or maybe even a Bigby's ____ Hand) and there you go! It would still be a powerful feat!

After binding them to the ground with magnetism, just make the watch as you send a meteor to the king. This is a whole lot more impressive -- to me, at least. I'm not sure if that fits into your campaign, though.

I really do hope this helps!

You'd need to get like an infinite (or to avoid upsetting some thin-skinned people who protest the use of the word infinite, let's just say arbitrarily high) amount of electricity in order to get any kind of non-negligible amount of force out of that, though. And even having that doesn't manage to remove the difficulty of the fact that when the players stop moving, there is no longer a force on them. Or that they still need to be electrically charged somehow.

[Fax Celestis]

Here, enjoy Kellus' psychomagnetism discipline (http://www.giantitp.com/forums/showthread.php?p=3673356#post3673356). Very easily converted to spells, if you're willing.

[Tragak]

This has been bugging me for a while now: seriously, where did the "catgirl dies when you do science" meme come from? :smalltongue:

[dascarletm]

Dangit! I came too late to the science party.:smallfrown:

[Fax Celestis]

This has been bugging me for a while now: seriously, where did the "catgirl dies when you do science" meme come from? :smalltongue:

"Every time you try to bring physics into D&D, the Burning Hate (http://community.wizards.com/go/thread/view/75882/19558798/Pelor,_the_Burning_Hate) Pelor kills a catgirl. Please, think of the catgirls."

[Sikening]

If you do want to impress them, you could employ a Sephiroth tactic. Just pull a meteor of course and aim it at a kingdom. This wouldn't be difficult to do either. A few divinations, a conjuration spell, (or maybe even a Bigby's ____ Hand) and there you go! It would still be a powerful feat!

After binding them to the ground with magnetism, just make the watch as you send a meteor to the king. This is a whole lot more impressive -- to me, at least. I'm not sure if that fits into your campaign, though.

I really do hope this helps!

That would work really well, actually. Except that the party actually hates the king, because "The King is an idiot."

The emporer of the neighbouring continent, however...