any materials?

[darqueseid]

is there any material substance that stops magical effects?  I've seen DM's Rule that lead or adamantine or similar dense materials can stop magic effects in a blanket fashion, but I haven't seen any specific rules on the matter(pun intended).  ;-) 

[Sinfire Titan]

Lead can block some Divination effects, and any solid material can block line of effect/sight (which is often required to cast spells), but I'm not aware of a specific material that has antimagic properties.

[vinom]

Which is odd, you could have a 15' wall of lead between the center of a fireball and one of it's victims...

[Aradu]

And such a wall of lead would block line of effect, protecting from the fireball completely unless it can spread around the wall. What's odd about that?

[vinom]

What's odd is that the flame that extends 20' from the point of origin in a maze of 1'' corridors a mile high could travel 100' to a point it can effect but not up 25' to a point it won't

[Vicerious]

Fireball used to fill a volume in previous editions of D&D, so you could use it to fill a very long, narrow corridor with flames.  The math was hell, though.  Sure, the hard radius of a fireball may not be strictly realistic, but it streamlines gameplay.

[darqueseid]

does this line of effect you speak of extend to spells like mages disjunction and the ilk?  spells that don't have visible effects, or does it penetrate the barriers.

for example if you use a disjunction outside a closed door, would it also disjoin creature/objects in the room that are within the area of the disjunction?

[Vicerious]

Line of Effect

A line of effect is a straight, unblocked path that indicates what a spell can affect. A line of effect is canceled by a solid barrier. It’s like line of sight for ranged weapons, except that it’s not blocked by fog, darkness, and other factors that limit normal sight.

You must have a clear line of effect to any target that you cast a spell on or to any space in which you wish to create an effect. You must have a clear line of effect to the point of origin of any spell you cast.

A burst, cone, cylinder, or emanation spell affects only an area, creatures, or objects to which it has line of effect from its origin (a spherical burst’s center point, a cone-shaped burst’s starting point, a cylinder’s circle, or an emanation’s point of origin).

An otherwise solid barrier with a hole of at least 1 square foot through it does not block a spell’s line of effect. Such an opening means that the 5-foot length of wall containing the hole is no longer considered a barrier for purposes of a spell’s line of effect.

All spells require line of effect unless they specifically state otherwise.  A disjunction will not affect creatures you do not have line of effect to.