Rage (Un/Chained Hybrid):
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 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 morale bonus on melee attack rolls, 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 and disappear when the rage ends. If the barbarian enters rage again in the same combat that her last rage ended, she regains the number of temporary hit points that she had remaining at the end of the previous rage, if any. A fresh pool of temporary hit points will only be available to the barbarian upon the ending of combat. While in a rage, a barbarian cannot use any Charisma, Dexterity, or Intelligence based skill (except Acrobatics, Fly, Intimidate, and Ride) or any ability that requires patience or concentration (such as spellcasting).
A barbarian can end her rage as a free action, and is fatigued after rage for a number of rounds equal to two times the number of rounds spent in rage (minimum 2). 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.