Each level of Barbarian gives you +2 Loincloth Grit.
If you are unarmored, your maximum Grit increases by this amount.
You can choose to enter a Rage at any time. While raging, you get +1 Attack and +1 Damage, and are immune to pain and fear. However, you cannot do anything defensive, curative, or cooperative.
Mostly all you can do is attack things in different ways. Any spell you cast must be a damaging spell.
Your rage ends when all enemies are destroyed or driven off. You can attempt to end a rage prematurely at the end of each turn with a 2-in-6 chance of success.
If you are surprised, you have a 50% chance to act on the surprise round anyway.
If you spend a turn slamming some hard alcohol, you can heal yourself 1d6+1 HP and gain 1 point of Drunkenness. (Note: Drunkenness expands your crit fumble range by an equal amount.)
Once per day, you can either treat your Strength as if it were 10 for one round, or make a single attack with a +4 bonus that does double damage if it hits. This bonus stacks with Rage.
The bonuses from your Rage improve to +2 Attack and +2 Damage