Magicka: Limitations
Brandon Sanderson's Second Law of Magick
Limitations > Powers
We're telling stories here, so hear it from a storyteller: What you can not do with your powers is far more interesting than what you can do with them. Of course your wizard could be a wunderkind who never does anything wrong and excretes rainbows, but where's the fun in that?
Let me give another example. How much RP does my character knows how do do the thing generate? None. The best case is that they'll be useful for a brief moment when someone else needs the thing done.
However, not knowing how to do the thing puts your character into a conflict: They want something. And dealing with conflicts generates RP...
Our magic is limited. How precisely is always up to you as a player, but please keep in mind it is this what makes your character interesting and not how many Daedra they can summon or how many shots they can drink.