You are able to deflect an incoming attack, creating an opening for you to launch a quick counterattack.
Prerequisite: Two-Weapon Defense, Two-Weapon Fighting, base attack bonus +6
Benefit: When fighting with two weapons, you may declare that you are parrying, requiring you to give up all your attacks for the round with either your primary or off-handed weapon. You gain an enhancement to your shield bonus to armor class equal to the number of attacks you have given up. If your opponent attacks and misses your armor class by a number equal to or less than your shield bonus, you may make an immediate attack with whichever weapon you are not parrying with. This attack is considered an attack of opportunity.
Special: A fighter may select Riposte as one of his fighter bonus feats.