Players sit around a table then one of them tosses his coin. He must catch it, and has three tries before drinking. If it comes up heads he says "1 head" and its the next player's turn. If it is tails he says 'O heads', each player takes it in turn adding 1 to the number of heads if the coin comes up heads or repeating the former number of heads if not.
When someone it gets to '5 heads', the player who got the fifth head nominates a shot, at 10 a second shot is nominated, 15 is a mixer, 20 goes and buys it. The unlucky soul who tosses the 25th head has to down it.
Very amusing especially when you get to see the foul concotion… one of the worst I've seen come up was a tequila-baileys-beer…. Not very nice.
If anyone's coin hits the roof and is then successfully caught, he can nominate a player who must immediately drink.