Smashing Dent (Combat)Source Weapon Master's Handbook pg. 17
Your hammer strikes cause traumatic injuries.
Prerequisites: Str 13, Improved Sunder, Smashing Crush, Smashing Style, Weapon Focus with the chosen weapon, base attack bonus +6.
Benefit: While using Smashing Style, each time you damage a suit of armor with a sunder combat maneuver, you reduce its armor bonus to its Armor Class by 1 and increase its armor check penalty by 1. Armor cannot have its armor bonus to AC reduced to less than 50% of its normal bonus or its armor check penalty more than doubled. These reductions and increases both end when the damage dealt by the sunder is repaired.