You are trained at using your combat skill for defense as well as offense.

Prerequisite: Intelligence 13.

Benefit: When you use the attack action or the full attack action in melee, you can take a penalty of up to -5 on your attack roll and add the same number (up to +5) to your Defense. This number may not exceed your base attack bonus. The changes to attack rolls and Defense last until your next action. The bonus to your Defense is a dodge bonus (and as such it stacks with other dodge bonuses you may have).

Normal: A character without the Combat Expertise feat can fight defensively while using the attack or full attack action to take a -4 penalty on attacks and gain a +2 dodge bonus to Defense.