This ran at the 2008 Hide and Seek Festival with an "attack/defence" combat mechanic, but was redesigned in 2009 to use rock-paper-scissors. Testing it at the ICA in February, it seemed to go pretty well - making it rock-paper-scissors certainly streamlines it, and makes it much quicker to explain.

Players still seem fairly reluctant to wander very far at all from the starting point, though; I guess there's not a lot of incentive, unless you've got a high-scoring hand and want to hide out. It might be worth forcing the players to spread out for five minutes and wait for a starting bell, to encourage a bit of careful stalking and some random encounters.