I've been thinking a little bit about a magic system from first principles – ie. what are the types of magic? It'd be nice to have the versatility to support different interpretations of magic in folklore and popular culture.
For example – Sources (of knowledge or power):
* Innate
* Learned
* Channeled (as from a place)
* Bargained for (as with a demon / fairy)
* Bequeathed (as by a patron / deity)
* Activated (wands / staves / etc)
* Stolen (consuming life force of others)
* Sacrificed (consuming life force of self)
Traditions / Foci:
* Runic
* Literate / Wizardly
* Blood
* Death / Bone
* Fertility / Sex
* Dream / Astral / Trance / Fasting
* Alchemy
* Herbalism / Pharmacology
* Techno-magic (clockwork, etc)
* Elemental
* Psychic
* Folk / Subtle Magic
* Shamanic
* Spirit
* Symbolic (numerology, etc)
* Energy stuff (chakras, ki etc)
* Place magic (ley lines, etc)
* Fairy
* Planar
* Divine
It might be interesting to apply some other lenses: "schools" of magic common to different traditions (perhaps sort of like the D&D staples of enchantment, necromancy, etc); type or length of casting (ritual / cantrip / invocation / ...). It'd be kind of cool to let players mix and match these to some extent – to be able to make a folk wizard who has a little innate power (can cast a few simple cantrips), but who must strike a bargain with a demon for serious effects.
I hear the Changeling RPG has detailed systems for entering into contracts with mortals / demons / fairies, which seems like an excellent flavoursome way to establish a cost to magic. Other potentially cool cost mechanisms: making magic slow (a prepared wizard is a terrifying adversary, but if you run up and stab him in the face ...); making magic dangerously unpredictable (especially if you try to use it quickly, etc); making magic consume rare, strange and adventure-demanding material resources; making magic dangerous to your character's mental health; making magic attract the attention of terrifying things; making magic cause exhaustion or physical trauma.
Just dumping some ideas in the hope they spark something.
EDIT: just re-read the thread leading up to now and see Agamemnon nailed down the magic system sometime in 2015. Is it Thursday yet?