SRD:Wall of Force

A wall of force spell creates an invisible wall of force. The wall cannot move, it is immune to damage of all kinds, and it is unaffected by most spells, including dispel magic. However, disintegrate immediately destroys it, as does a rod of cancellation, a sphere of annihilation, or a mage’s disjunction spell. Breath weapons and spells cannot pass through the wall in either direction, although dimension door, teleport, and similar effects can bypass the barrier. It blocks ethereal creatures as well as material ones (though ethereal creatures can usually get around the wall by floating under or over it through material floors and ceilings). Gaze attacks can operate through a wall of force.

The caster can form the wall into a flat, vertical plane whose area is up to one 10- foot square per level. The wall must be continuous and unbroken when formed. If its surface is broken by any object or creature, the spell fails.

Wall of force can be made permanent with a permanency spell.

Material Component: A pinch of powder made from a clear gem.