Base Attack Bonus

The Base Attack Bonus (or BAB) is a number that represents a character or monster's skill at fighting that comes purely from his or her profession, training, and personal experience.

Benefits
Base Attack Bonus serves several roles in DDO:
 * It is added to all attack rolls with any weapon, including bare hands.
 * It determines the number of attacks in your attack sequence.
 * It determines player attack speed. Players receive progressively larger attack speed bonuses at +1, +5, +10, +15, and +20 BAB.
 * Several combat-related feats require a minimum BAB to unlock.

Progression
The BAB progression for players is based on their class (for creatures, on their HD), and follows one of the three following progressions:
 * +1 BAB per level, the best BAB progression, is reserved for the warrior classes (Barbarian, Fighter, Paladin, and Ranger).
 * +3/4 BAB per level, the second best BAB progression, is used by the Bard, Cleric, Favored Soul, Monk, and Rogue.
 * +1/2 BAB per level, the worst BAB progression, is used by the Sorcerer and the Wizard.

Since fractions are dropped rather than rounded, only classes in the first category start with a BAB of +1. Base Attack Bonuses gained from different classes, such as when a character is a multiclass character, add together.