I did a lesson like this for summer camp. I taught the students some roots, and had them make spells (Harry Potter theme). Then for fun, I had the students write their spells in big lettering on a piece of paper. I randomly chose spells for the students and taped them on their shirts for a wizards' duel. The students would stand back-to-back, walk three steps, and turn. The student who could say the spell on their opponent's shirt the fastest won.