When a wizard has a mantle, which reduces accuracy, that wizard still has a chance of casting the spell he chooses. But when it comes to School spells, I've noticed they ALWAYS fizzle, when their accuracy is manipulated by mantles, regardless of the percentage.
Nowadays, school spells aren't used very often. But if possibly there are new additions, which people may find useful, it'd be good to have the chance to cast them even with decreased accuracy, because as of now it's not possible. I've not seen even one time a person has managed to cast a Shrike for example, when having a accuracy decreasing charm on himself...Since the last update on the shadow creatures they're more useful to use. They do have 100% accuracy for cast but will always be fizzled if it becomes lower.. A fizzle could mean the loss of a PvP match, if the person uses the shadow creature strategy. A loss to a definite fizzle isn't satisfying.
It's very discouraging to use spells, which you know you're gonna fizzle easily if a person manipulates their accuracy.