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. BAB is an important part of your total attack bonus. It also affects your attack speed.

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 is capped at 25 since U56
 * It determines player attack speed:
 * For melee weapons, attack speed increases at BAB 1, 3, 5, 10, 15, 20, and 25
 * For bows and thrown, attack speed increases with each point of BAB, and it grows much faster than for melee.


 * Several combat-related feats require a minimum BAB to unlock.
 * The Physical Resistance Rating that you receive for wearing armor scales with BAB.

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).
 * +.75 BAB per level, the second best BAB progression, is used by the Alchemist, Artificer, Bard, Cleric, Druid, Favored Soul, Monk, Rogue and Warlock.
 * +.5 BAB per level, the worst BAB progression, is used by the Sorcerer and the Wizard. Epic levels also use this progression.

Fractional BABs are rounded down to the nearest whole number. To calculate BAB of a multiclass character, first round down the total BAB for each class, then add numbers together. For example, a level 3 character with one level of rogue, one level of bard, and one level of sorcerer has a BAB of 0 (floor(0.5) + floor(0.75) + floor(0.75)), not a BAB of 2 (floor(0.5 + 0.75 + 0.75)). A level 9 character with 1 rogue and 8 barbarian levels has a BAB of 8 (floor(8) + floor(0.75)).

At epic levels, BAB increases by 1 every second level. Legendary levels do not increase BAB.

Since Update 56, BAB is capped at 25.

Multiple Numbers on Class Pages
The BAB column on class spreadsheets indicate multiple numbers. The first number listed is the Base Attack Bonus. Subsequent numbers indicate the attack bonus the character achieves on various stages of their attack sequence.

Increasing base attack bonus
Certain spells and abilities make your base attack bonus equal to character level:
 * Bladesworn Transformation
 * Divine Power spell
 * Warpriest enhancements T5 - Divine Power toggle
 * Past Life: Student of the Sword clicky
 * Tenser's Transformation spell
 * Eldritch Knight enhancements T4 - Knight's Transformation toggle
 * Warchanter enhancements core 5 - Victory Song toggle
 * Enlightened Spirit enhancements core 6 - Ultimate Enlightenment
 * Divine Crusader T2 - Holy Mantle
 * Vile Chemist enhancements core 4 - More Hidden Blades Orichidium Reaction

Additionally, Flurry of Blows allows a centered monk to receive a full BAB progression for all monk levels, rather than the standard 0.75.