Have Fun
All the players sit in a circle around the pitcher, and pour one beer into it. The first person in the circle then starts drinking (as much or as little as they want) from the pitcher, before passing it on to the next player, who does the same. The person who finishes the pitcher is the winner, whilst the player who drank immediately before the winner is the loser.
The loser must then buy a new pitcher of beer, and the whole game starts again. It is important that the pitcher is big, as this makes it harder to judge the amount of beer remaining.