By working with an ally to gauge the trajectory of incoming attacks, you can more easily avoid taking damage.
Benefit: Whenever you are able to see and hear at least one ally with this feat, you receive a +4 dodge bonus to AC against attacks from hurled rocks (or projectiles of similar shape, including bludgeoning ranged attacks from siege weapons). If you are hit by such an attack while you have this bonus, you can attempt a Reflex save to take only half damage from the attack. The DC for this save is equal to the bonus of the ranged attack used to hurl the rock.
Pathfinder Player Companion: Giant Hunter’s Handbook © 2014, Paizo Inc.; Authors: Alexander Augunas, Luis Loza, Ron Lundeen, and David Ross.