I was discussing some things with a friend, and the point was brought up that in a low- or no-magic setting, fighters and barbarians don't really get all that much better as far as damage. All the bonus damage they get is based on magic weapons and such.

So I got to thinking, how balanced would it be to allow bonus damage on attacks based on BAB?

The method my friend proposed was, after they're allowed a second attack, they gain bonus damage equal to the BAB of that second attack on the first attack, and after they get a third, they get bonus damage on the second equal to the BAB of the last attack.

IE, BAB 8/3, On the first attack, they get a +3 damage bonus. On the second, no bonus.

BAB 16/11/6, on the first attack they get +11 damage, on the second, +6, nothing on the third.

How bad would this be as far as game balance issues, especially in the higher levels?

Thanks in advance,
--Mullet