21 is a drinking game typically played by players sitting in a circle. The game begins with one player calling the direction of play by saying, 'To my left' or, 'To my right'. That player will then also say a number, or string of numbers. The choice of numbers will dictate the direction of the game from then on.

Saying one number (i.e. 'one') will cause the game to pass to the next player in line (and in the direction initially declared). Two numbers (i.e. 'one, two') will reverse the direction of the game from that initially declared. Three numbers will continue the game in the original direction will skip one player.

The onus of calling out the next number in the sequence will pass according to the string of numbers declared by the preceding player.

For example, an initial call of 'To my left, one', will mean that the player to the immediate left of the starter must say the next number, which in this case is 'two'. Alternatively, a call of 'To my left, one, two', will mean that the player to the immediate right of the starter must say the next number, which in this case is 'three'. Finally, a call of 'To my left, one, two, three', will mean that the player to the immediate left but one must say the next number, which in this case is 'four'.

The player with the onus of calling the next number has the same option; he may call one, two or three numbers. The direction of play will chop and accordingly.

Assuming there are no mistakes, the game will continue in sequence up to number 21. The player who finds himself burdened with calling number 21 is liable to consume his entire remaining beverage.

Mistakes

1. Failing to call out the next number in the sequence when it is your turn to do so, or only after undue hesistancy.
2. Calling out the wrong number.
3. Calling a number out of turn.
4. Breach of new rules

A mistake will cause the sequence to stop. A penalty will then be issued to the player at fault before the game restarts.

The penalty for a mistake is usually an order to consume two finger's width 'fingers' of one's beverage.

The object of the game is to ensure the sequence continues to number 21 - the group objective. At the same time players will not wish to be the one to say 21 and be liable to consume their entire beverage, so skillful use of the numbers will be required to direct the play away from themselves. Clearly this is a game of concentration.

When the sequence reaches 21, the losing player having just consumed their entire beverage is given the consolation of making a new rule to the game, before it begins again.

During the game, players will periodically need to visit the bar to replenish their drinks (it is best to buy in large rounds so that the number of trips is minimised). Sometimes, the person at the bar will miss the end of a sequence and its consequent new rule. In some traditions such people must not be told the new rule, but must work it out through observation and trial and error. The same applies to anyone joining the game haflway through.

Suggested new rules

• Individual Numbers in the sequence may be switched around or replaced with words, actions, quotations or lines from songs. For example, "7 is now a Beatles song". A particularly troublesome rule is to replace number one with 'To my left'. Hence the sequence might begin, 'To my left; To my left; Two.' (It goes right!)

• The magic properties of two-numbers and three-numbers may be reversed. That is, "12, 13" will cause play to skip while "14, 15, 16" will reverse it. This rule goes some way towards evening up players of differing experience, since the conventional system is ingrained habit for the old guard, whereas to the novices they're just arbitrary rules that can easily be swapped.

• Number 20 could be replaced with 'Ha Ha! You are finished!'

• Anyone who makes a mistake at number 20 (thereby preventing a complete sequence) is liable to the 21 forfeit.

• The Empty Glass Rule. When you finish your drink you must tap it on your chest before placing it on the table. Failure to do so incurs liability to completely finish a whole new beverage. (Funny when someone has just struggled to see off the first!)

International drinking rules

This game is best played according to the International Drinking Rules.

See also: 21, Number 21