CAVEAT: This screed is still in progress.
One disadvantage of a d20 system is that the smallest number you can add to the roll of a 20-sided die is +1. That might not sound so bad, but in practice, it means that the chance to succeed or fail in any endeavor must be incremented in 5 percent chunks. That's because the odds of rolling any particular number on a d20 is five percent; for a span of numbers from 1 to 20, you have a 1 in 20 chance of rolling a given number, that is, 5 in 100, that is, 5 percent.
The reason that kind of sucks is that if your fighters improve in fighting by +1 every level (as they do in 3E Dungeons and Dragons), then a base attack progression by less able characters needs to advance by less than +1 per level. That means you have to use fractions of one sort or another.
A wizard, for example, progresses in fighting by +1 every two levels. That's the same as +0.5e per level on average over an even number of levels. A cleric progresses by +3 every four levels; that's 0.75 per level, on average. But the designers of 3.5 chose to keep the attack increments as +1s, not as fractional bonuses. This quantization (that is, the decision that all d20 adjustments must move in chunks of +1 or some other whole number) leads to an unfortunate problem: not all levels of a class are equal. Some levels grant a +1 to BAB; others grant only +0.
The same goes for saving throws. At some levels, you get a +1; at others, +0. The same chunkiness is at play here. And it is worth noting that feats and ablity score bosts also come at certain levels and not others.
These trends come together at certan levels. Take level 5. If you are a cleric, you get no attack advancement, no save advancement, no feat, no abilty advancement. But you get a third level spell, so all is well, right? Consider the bard. Also gets no BAB or save progression, no feat, no ability boost, no new spell level, no new bard music.
So once again we are at variance with the design goal that all levels should be equivalent. By keeping BAB and save progression chunky, some levels become more useful than others.
I suggest that we forget the chunkiness and use fractions. Progress BAB and saves by a fraction every level. Add up all your fractions to get your final BAB or save, and then round fractions of 0.5 and greater up! Here's how it would work:
........Weak Attacks......|..Medium Attacks....|..Strong Attacks..
Lvl.....Fracs.....Rounds..|..Fracs.....Rounds..|..Fracs.....Rounds
..1.....0.50........+1....|...0.75.......+1....|...1.00......+1
..2.....1.00........+1....|...1.50.......+2....|...2.00......+2
..3.....1.50........+2....|...2.25.......+2....|...3.00......+3
..4.....2.00........+2....|...3.00.......+3....|...4.00......+4
..5.....2.50........+3....|...3.75.......+4....|...5.00......+5
..6.....3.00........+3....|...4.50.......+5....|...6.00......+6
..7.....3.50........+4....|...5.25.......+5....|...7.00......+7
..8.....4.00........+4....|...6.00.......+6....|...8.00......+8
..9.....4.50........+5....|...6.75.......+7....|...9.00......+9
.10.....5.00........+5....|...7.50.......+8....|..10.00.....+10
.11.....5.50........+6....|...8.25.......+8....|..11.00.....+11
.12.....6.00........+6....|...9.00.......+9....|..12.00.....+12
.13.....6.50........+7....|...9.75......+10....|..13.00.....+13
.14.....7.00........+7....|...10.50.....+11....|..14.00.....+14
.15.....7.50........+8....|...11.25.....+11....|..15.00.....+15
.16.....8.00........+8....|...12.00.....+12....|..16.00.....+16
.17.....8.50........+9....|...12.75.....+13....|..17.00.....+17
.18.....9.00........+9....|...13.50.....+14....|..18.00.....+18
.19.....9.50.......+10....|...14.25.....+14....|..19.00.....+19
.20....10.00.......+10....|...15.00.....+15....|..20.00.....+20
Take a common multiclass combo, the Mystic Theurge. A wiz3/cleric3/MT3 has a BAB of +4. But if you look at it fractionally, the PC should have a +1.5 from three wizard levels, a +2.25 from three cleric levels, and a +1.5 from three MT levels. That should be +5.25, rounded down to +5. That's better.
This is part three of an ongoing series on How I Would Fix D&D 3.5.
