Another adaptation of board games, this one obviously to Backgammon. A pretty tame game, that just gets tamer.
Play the game as usual. Any time one of your pieces gets sent to the bar, drink. As well, each time you take a piece off the board, drink again. Pretty straightforward.
Drinking is based on a full 12 ounce beer. The beer is divided into six parts (two ounces each).
Every time your opponent rolls doubles, you do a corresponding number of drinks. For example, for double twos you would drink two parts of a beer (four ounces). Double sixes is a full beer, etc.
The loser owes one full chug (12 ounces).
Being gammoned is two chugs, backgammoned is three chugs, and a bargammon (very rare event, but it happens) is four chugs.