The character can roll with a potentially lethal blow to take less damage from it than he otherwise would. Once per encounter, when he would be reduced to 0 or fewer hit points by damage in combat , he can attempt to roll with the damage. To use this ability, the character must attempt a Reflex saving throw . If the save succeeds, he takes only half damage from the blow and can be reduced to one hit point at most from the specific attack; if it fails, he takes full damage. He must be aware of the attack and able to react to it in order to execute his defensive roll—if he is denied his Dexterity bonus to AC, he can’t use this ability. Since this effect would not normally allow a character to make a Reflex save for half damage, any evasion ability the character has does not apply to the defensive roll.