Attacking an Object
Hardness
Attacking a Shield
An opponent with a shield can be troublesome. However, the destruction of an enemy's shield can be fairly easy. This may not be attempted with any weapon that deals sublethal damage or that can be finessed - these are too light.
This cannot be done against cloth wraps or cloaks used as shields.
Whenever an opponent has at least 1 point of shield bonus to AC, and you are attacking with a melee weapon, you may choose to automatically fail your next attack roll (this must be declared before the attack is rolled) and attack their shield instead. This automatically hits, as they will be trying to block your weapon with their shield. You do full damage, negated as usual by the shield's hardness.
This applies only as long as the opponent is unaware of what you are doing. A (DC 18+your CA) sense motive check will reveal what you are doing. After this, you must attack the shield per normal rules, listed above, as if it were a weapon or other item held in the hand.
If the shield is destroyed by one of these attacks, it splinters in half and becomes useless, and you immediately deal half damage to the wielder. Unlike Armor, heavily damaged shields are just as functional as those which are brand new.