I'm trying to create a realistic magic system that is both powerful and limited. Brandon Sanderson claims that the best magic systems are ones with consequences and limits, and I wholefully agree. I love realism and logic applied to magic. So far, however, I cannot come up with a balanced system. The only one of interest has been elemental, but I think that's cliche and has lots of loopholes. I need a system that's not too simple or too broad, and one that can be combated by normal humans with the ability to negate magical powers but by no real magic of their own. Any thoughts?