Rules of the Caps are quite simple.
Required equipment are two (minimum) bottles of beer
and one extra cap of a bottle.
Two players are sitting on the grass face to face with straightened legs and soles together so there forms a diamond <> as a field.
Both players have to open a bottle of beer (1/3 l) and set it between their thighs with opened cap upside down on it.
With third cap one after other are trying to throw the opponents cap down from the bottles mouth. With every hit opponent has to take a sip of beer and with five sips the bottle must be empty and drinker has lost the game.
If the cap is dropped otherwise i.e. just pushing the bottle accidentially by hand drop is as accepted as normal hit. Dropper's own fault :)
For example with 5 players a league will take 4 bottles per player and the more players the more beer... Result is that everyone won and it's fun.