Your nimble moves often allow you to flip away from a foe’s attack.
Benefit: As an immediate action when you would normally be hit with a melee or ranged attack roll, you may make an Acrobatics check to avoid being hit. The DC for this check is equal to the attack roll that hit you. You gain a free 5‑foot step as part of this Acrobatics check, and must take it. (If you cannot take your 5‑foot step, you cannot use this feat. The movement doesn’t count against any other movement you are taking, and does not provoke an attack of opportunity.) You may only use this feat when you have an armor check penalty of 0, are carrying no more than a light load, and are not wielding a two‑handed weapon or shield. You may use this ability a number of times per day equal to 3 + your Dexterity bonus.
Adventurer’s Handbook: Genius Guide Volume 1