Making an anti-magic room

[Lysander]

Here's a spell that might prove handy for dungeon construction, either used by the PCs or by the creator of the place they're invading:

Anti-Magic Room
Abjuration
Level: Sor/Wiz 7
Components: V, S, M, F
Casting Time: 24 hours
Range: Touch
Target: Cube of cold iron 1ft wide
Area: 40-ft.-radius area, centered on cube
Duration: Permanent
Saving Throw: None
Spell Resistance: See text

You enchant a cube of cold iron to emit a large anti-magic field. The cube becomes entirely fixed in space. It is no longer affected by gravity and is resistant to being moved, requiring a DC30 strength check to dislodge it. If it is ever moved from its position the Anti-Magic Room spell on it immediately ends. The cubes are often built into walls or under floors to create antimagic fields with no clear source.

Material
8,000gp in cold iron fillings spread around area

Focus
Cube of cold iron costing 5gp

[Milskidasith]

Seems rather expensive, but aside from that it looks fine. I can't remember, though, but can't emanations be blocked by walls? You'd only need to put a concrete slab between you and the block and you'd be casting away happily.

[Lysander]

Seems rather expensive, but aside from that it looks fine. I can't remember, though, but can't emanations be blocked by walls? You'd only need to put a concrete slab between you and the block and you'd be casting away happily.

Good point. Let me fix that.

[sciencepanda]

Since it isn't affected by gravity, would it eventually just float off into space, as the planet orbits away from it?

[BRC]

Since it isn't affected by gravity, would it eventually just float off into space, as the planet orbits away from it?

Come to think of it, an Immovable rod is an incrediably powerful weapon. You place it there, then the rotation of the planet flings your enemies into it at incrediably high speeds.

[arguskos]

So, here's a question: could you make a series of flying platforms with these? They ignore gravity, how much weight do they support?

[Mulletmanalive]

2.5 times the maximum load of the mimimum strength needed to move it [assuming that the lack of leverage from it's non-grounded position reducing the drag limit by half] is 1,600lb x 2.5 = 4,000 lb.

I personally wouldn't disallow gravity to affect the cube, but that's just me...I can't see why negating magic would allow it to negate gravity's effect on it, especially given that it would negate any magical force holding it in place.

[Lysander]

2.5 times the maximum load of the mimimum strength needed to move it [assuming that the lack of leverage from it's non-grounded position reducing the drag limit by half] is 1,600lb x 2.5 = 4,000 lb.

I personally wouldn't disallow gravity to affect the cube, but that's just me...I can't see why negating magic would allow it to negate gravity's effect on it, especially given that it would negate any magical force holding it in place.

It's not immune to gravity per se. The AM field is just fixed in space and the cube is stuck in the center. Normal gravity isn't strong enough to move it.

[Mulletmanalive]

Supporting a wooden stairwell up to some kind of fortress on these things might be interesting...

This is a heck of a lot cheaper then the enchantments that i was planning to use on my Mission Impossible style embassy so i'll use this i think. Probably keep the thing immovable but you'd never know it...I wonder what the market prince on 25 8th level spells is...

[Lysander]

Per immovable rod rules, which is what I based the DC to move them off of, each cube could support up to 8,000 pounds. So you could theoretically support a platform or staircase with them.

The danger is, if they're ever moved the spell ends and they drop. So a platform held up with immovable rods might sag under a heavy weight, this would simply collapse. It would take a lot of weight though.

[Mulletmanalive]

Hardly matters. I'll be needing to either change the area of effect or using Shape Spell to actually make it fit my purposes anyway. I'll be using it on an underground structure and unchecked antimagic would be somewhat suspicious...