You grind down your opponent’s equipment until it breaks from wear.
Benefit: Any time you confirm a critical hit against an opponent or successfully make a sunder attempt against an opponent’s armor or shield, you reduce the armor bonus that equipment provides by 1 (if from a critical hit, you choose whether to affect the creature’s armor, shield, or its natural armor, as described in Bebilith Claw). Repairing the equipment to full hit points restores its lost AC bonuses. If an armor or shield’s armor bonus is reduced to 0, it is reduced to half hit points, gains the broken condition, and is unequipped from the creature, regardless of its current hit points or hardness. The equipment falls on the ground in the creature’s space.
Path of Iron, © 2015, Ascension Games, LLC; Author Christopher Moore