There is large group version of this game called 'Giants, Wizards, Elves'. Technically, the principles are the same. Giants can squash elves by standing on them, wizards can kill giants by casting spells on them, and elves can kill wizards by climbing up the backs of their cloaks and strangling them with their beards (graphic huh?).
There's none of this 'index and middle fingers extended' stuff either. This is role-play. Giants sway uneasily on their legs and shout 'Fee Fi Fo Fum' (okay, so they're stereotypes); Wizards throw their arms in front of them dramatically and shout 'Shazam', and elves extend their hands, wiggle their fingers and say 'Biddly widdly widdly' in high squeaky voices (it's in the rules, buster).
The game works best with about forty people, split into two equal teams. Each team decides what they're going to 'be' first, obviously without the other team hearing. The teams then line up in the middle of a large room, aggressively trying to stare down the other team (it's the attitude involved that makes this game fun). After a count of three, each team does their chosen character action... whoever wins the bout gets to chase the opposition back to the wall on their side of the room - all role-play ceases before the chase, obviously. Those that get back to the wall without being caught are safe. Those that do not must enthusiastically join the opposition. Teams then form conspiratorial huddles to decide what to be next.
It's a good game. Great moments include: draws which turn into wary stand-offs with many angry glances and hard gestures; the three second wait in between gesture and chase where players try to work out who's actually won; the one remaining elf being manhandled by thirty-nine giants.
'Giants, Wizards, Elves' is a 'New Game'.