d20 Rules Variant

Standard Rule

When a player character multiclasses, the modifiers they receive to base attack bonus and saving throw bonuses are computed individually for each class, then added. This leads to interesting minmaxing effects, since fractional bonuses are dropped prior to aggregation. The computations per bonus are:

BAB_class = floor(class level * (cond((strong,1),(medium,0.75),(weak,0.5)))
BAB = SUM_classes BAB_class

Save_class = cond((strong,2),(weak,0))+ floor(class level * (cond((strong,0.5),(weak,/3)))
Save = SUM_classes Save_class

Variant Rule

Whenever a player gains a level, their fractional bonus is added to their current bonus, and, if that pushes them over an integer value, they gain the effect. In addition, any class with a strong Saving Throw gains the relevant Virtual Feat (Lightning Reflexes, Iron Will, Great Fortitude), all of which are modified to:

Gain +2 class bonus to your relevant saving throw. If you take this feat again, this modifier is only +1, but stacks.

The new computations are:

BAB = floor(1.0*(strong class levels) + 0.75*(medium class levels) + 0.5*(weak class levels))

Save = Feat modifier + floor((strong class levels)/2 + (weak class levels)/3)