Spell Dampening (3.5e Creature Ability)

Spell Dampening
Spell resistance is well known as a binary defense against magic; it either fails or goes through full strength. But some creatures hamper magic rather than have what boils down to armor class for magic. Summary::Spell dampening (and subsequently power dampening) reduces the caster level of the incoming spell for the purposes of determining how it affects the creature with SD, reducing its effectiveness, duration, range and other effects.

For example, a creature with spell dampening (SD) 5 which is hit with a CL 10 fireball is reduced to a CL 5 fireball, dealing 5d6 damage. Likewise, if struck by a CL 13 fireball, it becomes CL 8, dealing 8d6 damage. If the caster level reduction would put the creature out of range for the spell, the spell does not have an effect on the creature, even if it is affecting other, non-protected creatures. Spells which have been reduced to caster level 0 or less are effectively negated.

Spell dampening applies to any spells and effects spell resistance applies to. If a creature has both spell dampening and spell resistance, spell resistance is checked first.