Apok said:
The problem I have isn't with PrCs being more powerful than core classes - I expect that. It's that the spellcaster PrCs that give full spell progression require almost no sacrifice on the part of the character taking them, while the same isn't true for non-spellcaster PrCs.
Well, sadly this is the way spellcasters work. The Wizard and Sorc just don't have a whole lot going for them other than their spells. They've got the worst bab, worst HD, and only one good saving throw. Wizards get some bonus feats and Sorcs get a better familiar but that's about it. There just isn't a whole lot else to give up. This is why PrC's that don't give full spellcasting benefits need to offer something pretty substantial in tradeoff. Some existing PrC's do this well, others do not.
Another way of resolving this "PrCs are too good issue" would be to look at the base classes and make it more attractive to stick with them.
For example, clerics/sorcerers/wizards could be modified like this:
Clerics: Give domains more slowly, maybe one at 1st, 5th, 10th, 15th, and 20th (or until the deity offers no more.) This could be balanced by reducing the number of spells per day, maybe one less of each level (a 'nerf' that affects PrCs as well). Effect: PrC'ing would 'cost' domains.
Sorcerers: 4 skill points per level and/or bonus feats only applicable to sorcerer spells (thinking of things like eschew materials, spell themantics, improved counterspell, heighten spell, etc.; something appropriate for sorcerers, I think those are appropriate but rarely cost-effective). I'm not sure how this should be balanced (maybe use Monte Cook's alternate spell list with some of the 'best' spells bumped a level?), but some would say the sorcerer could use a boost anyway. Effect: PrC'ing would 'cost' skill points and/or feats.
Wizards: Separate the 2 free spells at each level from "+1 spellcasting level". Effect: PrC'ing would 'cost' free spells.
Imo, something like this (tinkering with the base classes) would be simpler than balancing all the hundreds of PrCs one-by-one.