Melt Defenses Feat (Combat)
You can dissolve key portions of your target’s defenses, making them easier to hit.
Base attack bonus +11
When you score a critical hit with an attack that deals acid damage, instead of applying the normal critical hit effect, you can disrupt the target’s defenses for 1d4 rounds. Attacks against a creature whose defenses have been disrupted in this manner target EAC, regardless of the attacks’ damage type.