You will need one ping pong ball and 12 glasses of beer. Arrange six glasses of beer on either side of a table as if you were setting up bowling pins. Divide yourselves in to two groups.
Each group should sit opposite the other with 6 beers in front of them. As you take your turn, you must throw the ping pong ball in to the opposite teams glasses. If it lands inside a glass, the opposing team must drink the beer immediately. Once done, rearrange the beers so they are all close to each other. The winning team is the team that manages to make the opposing team drink all their drinks. At the end of the game, the losing team must drink all remaining beer on the winning side.
I am about to go and get started on these games so my comments throughout the evening may become slurred. Oh – and remember the drink-driving rule: keep one eye shut. Just kidding.