Note 2018-06-05: Eldritch Realms has been renamed to Magonomia
The development team and I are continuing work on the magic system. This, of course, will be the defining rules section of the game, so it's important to get it right. Where we stand is that we have a roughed-out framework for how magic generally works and are starting into the details of creating spells.
Everything is still subject to change. I can say with confidence that the design of the magic system is inspired by historical (alleged) magicians such as Christian Rosenkruetz, Paracelsus, and Doctor John Dee. These are magicians of the intellectual tradition of European magic called Hermeticism, which shares a name, but little else, with the high-fantasy magic portrayed in the great RPG Ars Magica. So Eldritch Realms is inspired by (historical) Hermeticism, but I want it to also be inclusive of other kinds of magic from different places and times. If I get the design right, you'll be able to play a folk magician or a Turkish mystic and have just as fun and interesting a game as if you had played an Hermetic "magus".
On an unrelated note, I read The Elizabethan Underworld by Gāmini Salgādo last month as part of my research for Eldritch Realms. It's an accessible and interesting book full of inspiration for any GM. It's definitely going on the list of recommended reading in the back of Eldritch Realms.