Rage

A barbarian can call upon inner reserves of strength and ferocity, granting her additional combat prowess. At 1st level, a barbarian can rage for a number of rounds per day equal to 4 + her Constitution modifier. For each level after 1st she possesses, the barbarian can rage for 2 additional rounds per day. Temporary increases to Constitution, such as that gained from bear's endurance, do not increase the total number of rounds that a barbarian can rage per day. A barbarian can enter a rage as a free action. The total number of rounds of rage per day is renewed after resting for 8 hours, although these hours need not be consecutive. While in a rage, a barbarian gains a +2 bonus on melee attack rolls, melee damage rolls, thrown weapon damage rolls, and Will saving throws. In addition, she takes a –2 penalty to Armor Class. She also gains 2 temporary hit points per Hit Die. These temporary hit points are lost first when a character takes damage, disappear when the rage ends, and are not replenished if the barbarian enters a rage again within 1 minute of her previous rage. While in a rage, a barbarian cannot cast spells. A barbarian can end her rage as a free action, and is fatigued for 1 minute after a rage ends. A barbarian can't enter a new rage while fatigued or exhausted, but can otherwise enter a rage multiple times per day. If a barbarian falls unconscious, her rage immediately ends.