Benefit: Whenever you and an ally who also has this feat are flanking the same the creature, you deal an additional 1d6 points of precision damage with each successful melee attack. This bonus damage stacks with other sources of precision damage, such as sneak attack. This bonus damage is not multiplied on a critical hit.
Precise Strike (Combat, Teamwork)
Advanced Player’s Guide. Copyright 2010, Paizo Publishing, LLC; Author: Jason Bulmahn.