Magic can be applied in so many ways, I like the idea of specific magical disciplines, along the lines of 2nd Edition D&D. Here are the basics.
Abjuration
This school is focused on protective spells, as well as spells which cancel or interfere with other spells, magical effects or supernatural abilities. Wizards who specialize in this school are known as Abjurers.
Alteration / Transmutation
Spells in this school alter the properties of their targets. Wizards who specialize in this school are known as Transmuters.
Conjuration / Summoning
Is focused on instantaneous transportation, conjuring manifestations of creatures, energy or objects and object creation. Wizards who specialize in this school are known as Conjurers.
Divination
This school is focused on acquiring information. Wizards who specialize in this school are known as Diviners.
Enchantment / Charm
This school is divided into two subschools: compulsion and charm. Charm spell affect the targets’ attitudes, usually making them act more favorably toward the caster. Compulsion spells can force the targets’ to act in a certain way or avoid certain actions, affect the targets’ emotions or affect the targets’ minds in other ways. The Compulsion subschool also includes buffs. Wizards who specialize in this school are known as Enchanters.
Invocation / Evocation
Evocation is focused on damaging energy-based spells, it also includes conjurations of magical energy. Wizards who specialize in this school are known as Evokers.
Illusion / Phantasm
This school is divided into five subschools: figment, glamer, pattern, phantasm and shadow. Figment spells create artificial sensations with no physical substance. Glamer spells alter the target’s sensory properties, and can cause invisibility. Pattern spells create insubstantial images which affect the minds of the viewers, pattern spells can inflict harm. Phantasm spells create hallucinations which can be harmful. Shadow spells use magical shadows to create things with physical substance. Wizards who specialize in this school are known as Illusionists.
Necromancy
Necromancy spells involve death, undeath and the manipulation of life energy. Necromancy can usually be divided into three or four categories: spells that help or create the Undead; spells that hurt the Undead; spells that hurt other people; and spells that manipulate life in order to heal. Wizards who specialize in this school are known as Necromancers.
Universal
Universal spells have effects too broad to place into one class, or too useful for any specialist to consider forsaking. They often can perform multiple effects, or perform a very specific effect that does not fit into another category. The most famous of these spells is “wish”, the most powerful spell within the game, which can duplicate spells from all schools. As universal spells are not a school, per se, no one can specialize in them.
