Field Of Resistance

Level: Sorcerer 5, Wizard 5,
Components: V, S,
Casting Time: 1 standard action
Range: Medium (100 ft. + 10 ft./level)
Area: 20-ft.-radius emanation centered on a point in space
Duration: 1 round/level (D)
Saving Throw: None
Spell Resistance: No
Source: Player's Handbook II

The air in this spell's effect shimmers with arcane energy. A buzzing sound echoes in your mind as the flow of magic into the affected area chokes off and ends.

This spell creates a zone that impedes the flow of magic. The energy of this zone clings to creatures and objects, granting them a shield against spells.
All creatures in the spell's area gain spell resistance of 11 + caster level for as long as they remain in the area. If a creature already has spell resistance higher than this amount, this spell does not affect it. Unlike personal spell resistance, this spell resistance cannot be voluntarily lowered.
A creature loses this spell resistance when it leaves the spell's area, and gains it again if it returns.