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Fractional Base Bonuses
The progressions of base attack bonuses and base save bonuses in the Player’s Handbook increase at a fractional rate, but those fractions are eliminated due to rounding. For single-class characters, this rounding isn’t signifi cant, but for multiclass characters, this rounding often results in reduced base attack and base save bonuses.
For example, a 1st-level rogue/1st-level wizard has a base attack bonus (BAB) of +0 from each class, resulting in a total BAB of +0. But that’s only due to the rounding of each fractional value down to 0 before adding them together—the character actually has BAB +3/4 from her rogue level and BAB +1/2 from her wizard level. If the rounding was done after adding together the fractional values, rather than before, the character would have BAB +1 (rounded down from 1-1/4).
The table below presents fractional values for the base save and base attack bonuses presented in Table 3–1 in the Player’s Handbook. To determine the total base save bonus or base attack bonus of a multiclass character, add together the fractional values gained from each of her class levels.
For space purposes, the table does not deal with the multiple attacks gained by characters with a base attack bonus of +6 or greater. A second attack is gained when a character’s total BAB reaches +6, a third at +11, and a fourth at +16, just as normal.
This variant is ideal for campaigns featuring many multiclass characters, since it results in their having slightly higher base save and base attack bonuses than in a standard game. For example, in a standard game, a 5th-level cleric/2nd-level fi ghter would have base save bonuses of Fort +7, Ref +1, Will +4. In this variant, the same character would have Fort +7 (rounded down from +7-1/2), Ref +2 (rounded down from +2-1/3), and Will +5 (rounded down from +5-1/6).
Another example: A standard 2nd-level rogue/9th-level wizard would have a base attack bonus of +5, +1 from rogue and +4 from wizard. Using the fractional system, that character’s base attack bonus would be +6, +1-1/2 from rogue and +4-1/2 from wizard, enough to gain a second attack at a +1 bonus.
