M.T. Black
Hero
Thank you for the suggestions, they've been very helpful! Here's the current draft (flavor from Hermetic magic):
You can safely cast a number of spells per day equal to your level. Every time you cast an extra spell, you must Test INT afterward. On a failure, you lose your Astral Equilibrium and cannot cast spells again until you spend an hour in meditation.
Sample spells:
Elysian Rest - Put 1d6 HD worth of Nearby enemy creatures to sleep for 1 hour. Undead and constructs are immune.
Thoth’s Radiance - Blind 1d6 Nearby enemy creatures for 1 round.
Aetheric Veil - Create a large cloud of fog Nearby for 1hr.