Moment of Chance (3.5e Maneuver)

In desperate times, a Coin’s Edge adept can pool all their luck into a single moment of chance

You may initiate this maneuver after making a saving throw or whenever you are attacked, after the attack roll is made. If you initiate it after making a save, you may reroll that save, gaining a luck bonus equal to half your initiator level on the reroll. You must abide by the results of the reroll. If you initiate it in response to being attacked, you gain a luck bonus to AC against that one attack equal to half your initiator level. However, using this maneuver leaves your chances exhausted, causing you to take a -4 penalty on all saving throws and to AC until the beginning of your next turn. You also lose any luck bonuses on saves or to AC until the beginning of your next turn. This maneuver is a supernatural ability.