Anyone have any idea how exploding snap is actually played? I know Ron built a house out of the exploding snap cards once, but, uh, other than that I'm lost. Even off-the-wall theories would be nice.

I'm asking this because I just discovered part of a fic I had evidently started after HBP but subsequently forgot about. There is a scene wherein Neville sets off the exploding snap cards. This made me wonder wtf exploding snap is, anyway, because I really have no effing clue.