MoogleEmpMog said:
I suspect we differ on the definition of 'fundamentally' in this context.
IMO, a fundamental flaw is one intrinsic to the system or to the base elements thereof.
FUNDAMENTALS of the d20 system, IMO, are: the roll d20 + mods vs. TN resolution mechanic, and the breakdown of abilities into Race, Class, Level, Skill and Feat. I would be disinclined to admit specific examples of the five categories above as 'fundamentals' of the game, because as d20 Modern in particular demonstrates, they can be swapped out with no or almost no change to the mechanics for using them.
Wait, no one argued that the d20 system is fundamentally flawed.
3E is another beast. The strong connection between level in a caster class and casting power are fundamental in 3E, as far as I'm concerned. And I don't just mean caster level, but also access to high-level magic and spell slots. This connection is essentially what makes the multiclassing rules for casters broken.
Without a complete rewrite of all the caster classes this problem cannot really be fixed. And even then, there are a couple of other classes (like the monk) with similar problems, showing us that there were fundamental errors in class design.
Then you have the entire problem of Vancian magic and per day abilites with the 15 minute adventuring day, requiring a rewrite of the entire magic system (because spells are currently not balanced for per encounter), because again, fundamental assumptions for spells were wrong.
Along with that, you have the overly complex stat blocks, which make DM preparation, especially at higher levels, a pain. To mitigate that, you need to rewrite every single monster, because the fundamental assumptions of monster design were flawed.
All flaws that require rewriting of vast amounts of material are fundamental flaws, as far as I'm concerned, you cannot really solve them with anything but a new edition.
BAB, d20 mechanic, classes - these fundamental things are remaining. Stuff, that was built on that (spells, the way the classes were designed) - no.
BAB is bad. At low levels, there is next to no difference between fighters and wizards in terms of hitting things, at high levels the difference is so large that everything is either hit by fighters automatically, or cannot ever be hit by wizards. That is why the sweet spot is right in the middle.
A static difference (i.e. fighters always have around +5 on hit more than a wizard) extend the sweet spot to all levels, which is exactly what is required.
Saves suffer from the same problem, which is why in Saga, classes give static boni to them.