Channeling is divine magic in it's purest form - through direct divine intervention, you manifest miraculous powers in this world. It works only in worlds with very powerful and active gods.
Every channeler must have a patron, a divinity, spirit, demon, pantheon or other sentient force with an objective for the channeler to serve. Different patrons grant different powers and set up different limitations - and the channeler has no choice but to serve to the best of his abilities.
Channeling is rather primitive magic, in that you need not be refined or educated to practice it. Channelers tend to be very powerful sorcerers - direct divine support will do that for you - but know next to nothing about anything else.
Examples and References
The Bible, stories of saints, some DnD clerics.
Limitations
Faith
A channeling magician must have the approval of his patron, and that patron must attend to him and work miracles for him, or the magic will not work. Channelers must be very strict about how they live their lives; their patrons tend to be unusually jealous and demanding even for gods.
Focus
The channeler must always brandish the holy symbol of his god, or a scripture or religious artifact, in order to work his magic. Some channelers use staves as foci, other stone tablets, cruxifixes, some gift from a divine patron, a divine mask or some other sacred object.
Common Schticks
- Summoning - especially to harm supernatural agents of hostile gods
- Law
Summonables
Angels or other spirit servants of the patron