Maurizio84: Mage Type Opposed School(s) Available Races Minimum Stat
Mage None H,E,1/2E N/A
Abjurer <> Alteration H 15 WIS
Conjurer <> Divination H,1/2E 15 CON
Diviner <> Conjuration H,E,1/2E 16 WIS
Enchanter <> Invocation H,E,1/2E 16 CHA
Illusionist <> Necromancy H,G 16 DEX
Invoker <> Enchantment/Conjuration H 16 CON
Necromancer <> Illusion H 16 WIS
Transmuter <> Abjuration H,1/2E 15 DEX

i don't know much about D&D in general but in BG those requirements don't seem to be very high.