Using a breath weapon is a standard action. A dragon can use its breath weapon once every 1d4 rounds, even if it possesses more than one breath weapon. A breath weapon always starts at an intersection adjacent to the dragon and extends in a direction of the dragon's choice. Breath weapons come in two shapes, lines and cones, whose areas vary with the dragon's size. If a breath weapon deals damage, those caught in the area can attempt Reflex saves to take half damage. The save DC against a breath weapon is 10 + 1/2 dragon's HD + dragon's Con modifier. Saves against various breath weapons use the same DC; the type of saving throw is noted in the variety descriptions. A dragon can use its breath weapon when it is grappling or being grappled.
