Artoomis said:Here I'd apply a two-size penalty to the prone character (based on the logic that a meduim character is pretty darn small, effectively, when prone). Also, no bonus for four legs since the opponent is already prone. This effectively is a -8 for the prone character: not an auto-success, but pretty close in most cases.
Obviously the opponent stay prone even if you fail the opposed check, but you cannot get by.
I like that