play 21. you sit in a circle, and you go round, each saying consecutive numbers up to 21. you can say up to three numbers at one go however eg, if the perosn before you said 2, you can say 3, 3 4, or 3 4 5. if you say 2 the direction changes, so the person who said 2 has to say 6. if you say three numbers you skip a person, so the person next to you but one has to say 6. it's really difficult because people lose concentration of where you're up to. whoever gets it wrong has to down their drink