I've only seen the magic option twice in the game, and when I used it my character got the spell wrong. The battle options start out simple and lead to some pretty specific situations and/or options. I remember that once my party snapped a skeleton's spine off at the waist, and that the skeleton propped itself up and threw its sword at me. I had the options to dodge, duck, or stand there like a bump on a log. I ducked, and the sword missed me.