Half-fill a jug, bowl or large glass with beer and then place a smaller glass in the beer so that it floats.
Each player takes it in turns to try to add a coin to the glass without sinking it. The player who adds the coin to the glass that makes it sink must scoop out the glass, fill it with beer and down it.
The game can then start again until the jug is empty.
If you don’t have enough coins to make the glass actually sink, then weigh it down with a heavier object first.