Back in the day, they had 13 magic schools in the magic supplement for Drakar och Demoner Expert:
Animism, Demonology, Dragon magic (also worked a bit differently, dragons could innately use this but regular folks could as well but it was extra difficult), Elementalism, Harmonism (magic through musical performance), Witchcraft, Illusionism, Mentalism, Necromancy, Voice Magic (shouting words of power, invented by dwarves), Spiritism, Symbolism (based around drawing symbols, once activated they do things to those who see them), and Staff Magic (primarily an avenue to pursuing multiple schools at once which was otherwise difficult, but had some tricks of their own). They also had rules for alchemy (which didn't count as a separate school).