Called Shot

 
Prerequisite(s): Dex 13+
 
Benefit: On your action, before making attack rolls for the round, you may choose to subtract a number from all attack rolls for the round and add the same number to all weapon damage rolls for Dexterity-based attacks. This number may not exceed your base attack bonus. The penalty on attacks and bonus on damage apply until your next action.
 
Special: Creatures lacking anatomy or immune to critical hits are immune to this extra damage. Called Shot can be used with ranged weapons at ranges up to 30 feet.
 
Source: Net Book of Feats