Yeah, alright. That makes sense.
I'm not too sure about this, especially when the school's associated ability IS intelligence. What would you, or anyone, suggest to do about that?To cast a spell from a given school, you must have an Intelligence of 10+spell level, as usual, and the school's ability at 10+spell level. Saving throws are based purely on the school's ability. That way, MAD is introduced, the wizard is forced to spend money and effort increasing multiple ability scores, and his power goes down slightly.
So, break up conjuration into all the different sub schools, each with it's own associated stat?On the school:ability associations themselves, I find myself a bit dubious about necromancy and strength. Constitution seems far more fitting, both for the "withstanding powerful energies" and "vital life force" bits. If you're worried about one ability governing too many schools, perhaps make transmutation Intelligence? After all, If you're going to mess with the physical structures of matter, you'd better know what those structures are first. [I wouldn't count Conjuration towards anything, as it's broken up into so many little pieces]