Spell Penetration
From Compendium of Worldly Lore
Needs review
Source: Player's Handbook
Description: Your spells are especially potent, breaking through spell resistance more readily than normal.
Prerequisites:
Required for: Epic Spell Penetration, Greater Spell Penetration
You get a +2 bonus on caster level checks (1d20 + caster level) made to overcome a creature's spell resistance.