Once per rage, the barbarian can try to avoid serious harm from an attack. The barbarian must make a Fortitude save with a DC equal to the damage that would be dealt by the attack. The barbarian's armor check penalty applies on this saving throw. If the save succeeds, the barbarian takes half damage from the attack and the damage is nonlethal. The barbarian must elect to use this ability after the attack roll is made, but before the damage is rolled. A barbarian must be at least 10th level to select this rage power.