The only part of Rapaire's post that is actually accurate is the last sentence: "After this is done everyone retires to the closest bar, tavern, or pub where they drink until they puke and sing dirty ditties."
Still, that's always been the most important part of the game.
As for the number of men in a team, just remember Robert Louis Stevenson's rugby song:
Fifteen men on a dead man's chest Yo ho ho and a bottle of rum Drink and the devil had done for the rest...