Base Attack Bonus

Definition
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.

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

Since fractions are dropped instead of 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, stack.

Benefits
Base Attack Bonus serves several roles in DDO:


 * It is added to all attack rolls with any weapon, including bare hands.


 * For players, it determines the number of attacks in your combo cycle. From the EU Patch 1 release notes:
 * At Base Attack Bonus +0, a character will have two swings in their attack sequence.
 * At Base Attack Bonus +1 or +2, a character will have three swings in their attack sequence. As before, your third attack in the sequence will have a +5 bonus to hit.
 * At Base Attack Bonus +3 or higher, a character will have four swings. As before, your third attack in the sequence will have a +5 bonus to hit, and your fourth attack will have +10 to hit.


 * It determines player attack speed. From the EU Patch 2 release notes, 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. Since your BAB depends only on your classes and levels, other attack bonuses don't help unlock these feats early.

For more details on the number of attacks and corresponding bonuses as the BAB increases, refer to the combo chain page.