Ammo is a stat that dictates the maximum number of bullets that can be stored and fired from a weapon. As the weapon is fired, the number of available bullets decreases from the maximum to zero, at which point no more bullets can be fired. Weapons can be reloaded to regain bullets up to the maximum.
Math
The formula for clip size increase is:
Sources of ammo
A permanent Ammo buff can be obtained from Gold Urns.
