This ain't you typical RPG magic system. The story elements of Harn's Shek-Pvar are absorbed into the game mechanics with little effort. Advancement is based on your mastery level, your imagination in developing new spells, and willingness to part with esoteric items.
I love the collaboration between GM and player to develop new spells. To learn new existing spell depends on your mastery level and potency of the spell.
The price in game mechanics to pay for casting is not arduous but must be taken into account, especially in combat. The more you cast the more it will fatigue you and the great the penalties on all your skills and abilities. The price in storyline and setting cannon is a far higher cost. To be burned at the stake fr witchcraft is a high price indeed.
If you are looking for something to make the player think about the consequences of esoteric power, give HarnMaster and it's magic system a shot.