British Bulldog is a fabulously violent playground game. It can be played by any number of people.
Violence level ∝ Number of players / Size of playing field
Gameplay is simple. First, choose a rectangular playing field. Now, choose the first Bulldog. If your group of players is sufficiently psychopathic, there will be many volunteers.
Line up all players save the Bulldog on one edge of the playing field. On the Bulldog's signal (usually a hearty "1-2-3 British Bulldog!") the players run across the field to the opposite edge. The Bulldog's job is to catch them and hold them long enough to yell "1-2-3- British Bulldog!" once again.*
At this instant, the caught player is instantly ceases to be a noble creature fleeing the grasp of demons and the player's soul and base animal desires are fused into a bloodthirsty, hellborn monster with big claws and nasty, pointy teeth.
The remaining untouched players line up on the opposite edge of the playing field and await once again the Bulldogs' signal. The last one standing wins, and as a reward, becomes the NEXT beginning Bulldog in some perverted Strange Loop.
* Rules regarding legal captures and escapes are left to you.