Sense Weakness

Combat Expertise (PH) , Weapon Focus (PH) , INT 13,

Whenever you attack with a weapon with which you have selected the Weapon Focus feat, you may ignore up to 5 points of the target's damage reduction (regardless of the material or enhancement bonus of your weapon) or hardness. This benefit can't reduce the effective damage reduction or hardness of a target to less than 0.

Whenever you attack with a weapon with which you have selected the Weapon Focus feat, you may ignore up to 5 points of the target’s damage reduction (regardless of the material or enhancement bonus of your weapon) or hardness. This benefit can’t reduce the effective damage reduction or hardness of a target to less than 0.

You can take advantage of subtle weaknesses in your opponents’ defenses.