Wall of Force

A wall of force spell creates an invisible barrier in the locale desired by the caster, up to the spell's range. The wall of force cannot move and is totally unaffected by most spells, including dispel magic. But a Disintegrate spell will immediately destroy it, as will a rod of cancellation, or a sphere of annihilation. Likewise, the wall of force is not affected by blows, missiles, cold, heat, electricity, etc. Spells and breath weapons cannot pass through it in either direction, although Dimension Door, Teleport, and similar effects can bypass the barrier.

The wizard can, if desired, form the wall into a spherical shape with a radius up to one foot per level or to an open hemispherical shape of 1.5-foot radius per caster level. The wall of force must be continuous and unbroken when formed; if its surface is broken by any object or creature, the spell fails. The caster can end the spell on command.

[Player's Handbook]

School: Evocation
Level: 5
Rarity: Common

Range: 30 yards
Components: V, S, M
Duration: 1 turn + 1 round/level
Casting Time: 5
Area of Effect: Up to 10-foot square/level
Saving Throw: None

Material Components: a pinch of powdered diamond worth 5.000 gp (consumed)