It's A Kind of Magic - for Cortex
I'd already decided I want three kinds of magic (available to players). Sticking with Arcane, Druidic and Spirit I considered how to approach them in Cortex.
If you aren't familiar with Cortex, skills and stats are measured by die type starting at d2 and progressing d4, d6, d8, d10, d12 then picking up additional dice so d12 + d2 and so forth.
Skills are basic through d6, then specialize past that so one might have Firearms d6 / Pistols d10. I had at first considered treating Magic as a general skill and having the three types be specializations, but that would reduce the distinctiveness of each kind. I decided to make each type of magic it's own skill, with specializations within them. I'm also intending on providing at least one spell per die step through d12 so now I'll have generic spells for that kind of magic at d2 through d6 then individual specializations.
Arcane is easy, the specializations are Fire, Earth, Water and Air. Druidic will have Primal (nature spirits and forces of nature), Ancestral (tapping into ancestral wisdom and tribal spirits) and Oether - that name may change - (dealing with the Otherworld and entities from the Otherworld). Spirit will break down into Healing, Empathy and Inspiration.
Casters will need to have the Channeling trait to use magic. Spells will have thresholds based on complex action difficulties, which means in most cases channeling the magic to cast a spell will be a multiple round endeavor. Once the caster reaches the threshold then they make an actual casting action to target and release the spell. Add some flavoring to reflect fatigue and it will be good to go.
Now I just have to create and write up 39 spells (at least).