Hey, question. Kind of in the vein of the Magus base class I tried to write ages ago, what interest would there be in a spellcasting fix that puts forth 8 different specialist base classes, no generalist, and has spells learned in a manner similar to maneuvers? Specifically, your caster levels from all 8 stack, and you determine the maximum level of new spell you've learned by your total caster level. A generalist, then, would be represented by multiclassing between multiple of these, and might have a Master of Nine-esque PrC.
That's the basic concept, anyway, there are lots of details that need working out (such as what system to use for determining how many spells you can cast how often), but before I do all the hard work I thought I'd get some thoughts on it.
PROPOSAL
[spoiler]General Spellcasting Rules:Cantrips:
Cantrips are 0th level spells, and are generally not powerful enough to warrant inclusion in the above rules. All spellcasters know 5 cantrips of their choice. A cantrip can be forgotten and a new cantrip learned in its place each time a character gains a new caster level. A spellcaster can learn cantrips from any school. A spellcaster knows only 5 cantrips at any time, no matter how many spellcasting classes she actually has levels in. Cantrips may be used at will.
Multiclass Spellcasters:
A spellcasting character actually learns new spells and gains the ability to cast additional spells in a day at a fixed rate. While the table in each base class lists these for convenience, a formula should be used with a multiclassing character. A character learns 1 spell upon taking her first spellcasting level, plus one spell at each spellcasting level she takes (for a total of 2 spells known at her first level in a spellcasting class). At first, she gains a new spell per day at every second level. However, the number of spellcasting levels she must gain in order to gain another spell per day doubles every time she gains 2 spells per day since the previous doubling; thus, while she need only reach 3rd level to gain a 5th spell per day, and 5th level to gain a 6th, she must wait until 9th level to gain a 7th. These benefits accrue only for spellcasting classes, including prestige classes, but not for other classes. Thus, all spellcasting classes essentially have the same Spells Known and Spells per Day tables, and levels in all spellcasting classes (but not a character's caster level) stack for determining which entry is to be read from each.
When a character takes a second spellcasting class, she does not gain a new primary school. The school which would ordinarily be granted as a primary school, if any, becomes a secondary school for that character. If the class also granted a secondary school (or choice thereof), the character does not gain it. However, if the class granted only a secondary school, and no primary school, then the character does gain that. A character can only learn spells at a given level from her primary school and the secondary school(s) to which that particular spellcasting level grants her access. Thus a Necromancer 3/Evoker 1 whose choice of secondary school as a Necromancer was Divination could choose only Necromancy or Evocation spells for her Evoker level. A character who forgets a spell to learn a knew one can choose a spell from her primary school or any secondary school to which she has access.
Spell Failure: All spellcasting classes, even divine spellcasters, are now subject to spell failure chance for wearing armor. However, a spellcaster ignores any spell failure chance for armor whose proficiency feat she possesses; proficiency granted by virtue of taking levels of a class does not satisfy this requirement (unless the class actually grants the proficiency as a bonus feat). Additionally, casting failure does not apply as a percentage failure. Instead, for every 5% chance the armor ordinarily grants, the armor imposes a -1 penalty to the spellcaster's caster level, to a minimum of 0. A spell that would be cast at caster level 0 fails. Published spellcasters should be granted bonus feats for proficiency in the armors which their class ordinarily provides.[/spoiler]