I have never played FATE, but based on the way you described it I would say that its similar to how the magic system in Genesys works. Basic dice mechanic of the system has you build a positive dice pool based on the Ability and Proficiency of the the caster and a negative dice pool based on the Difficulty, and sometimes Challenge, of the spell. Since you construct the spell yourself you can limit the risk by making a weaker spell with less negative dice. However whether or not you pass the check it always puts mental strain on the caster. This is what is used to keep casters from constantly casting spells, they will eventually pass out.