Greater Called Shot

Int 13, Combat Expertise, Improved Called Shot, base attack bonus +6.

Whenever you make an attack, you can choose to replace that attack with a called shot. You can make multiple called shots in a single round. Each additional called shot after the first made in the same round takes a –5 penalty. In addition, a called shot that deals half the creature's hit points of damage (minimum 40) is a debilitating blow.

You can make only one called shot in a round as a full-round action. A called shot that deals 50 points of damage is a debilitating blow.