The essence of this game is simple...all you need to be able to do is count to 21. But unfortunately it isn't quite that simple!
Everyone should sit in a circle with a plentiful supply of alcohol in the middle. People count round the circle until 21 is reached. The person who says 21 then has to drink 2 fingers of a glass and set up a forfeit on one of the other numbers: for example "Whoever number 7 lands on in future will have to stand on a chair and declare their love to another person in the room."
The game continues with the next person in the circle starting back at number 1. When, for example, 7 is reached, the person should not say 7 but should stand on their chair and declare their love to someone. If they forget, then they have to drink 2 fingers, set up another forfeit on another number, and the game starts again from 1. Every time 21 is reached another forfeit should be set up. In this way forfeits are put on each number so that people are no longer counting but performing a series of forfeits corresponding to the numbers.
This gets rather confusing after a while, and whenever a mistake is made the person has to drink. The game can be made more complicated still by introducing direction changes instead of forfeits on some numbers. For example, whenever number 11 is reached you have to change direction, or whenever number 16 is reached you have to skip a person.
Work this one out if you can!
Click this animated image!