When you are selected as the target of a ranged attack, you utter a quick word to the air around you and wake it, compelling it to protect you against flying objects. As a result of this effect, you gain +1 to your AC against missile weapons until the start of your next turn.

At Higher Levels: The AC bonus increases by 1 when you reach 5th level (+2), 11th level (+3), and 17th level (+4).