High Noon is a game that is a little like a combination of a playground clapping game and rock paper scissors, but is much better than both. It is harder to explain than it is to learn and play...but here goes.
For two players, each faces the other over a table. Like a clapping game each player makes their moves simultaneously. The game begins with both players hand slapping the table (no:1 in accompanying picture). In their second move each player then decides whether to slap their left shoulder (pic 2) which is a safe move or to bring their hand up to their right shoulder (pic 3) which loads the gun, or to fire the gun (pic 4) at their opponent. After this second move each player then slaps the table again (pic 1) in unison and moves to their third move. The Hand Slap move must be made alternatively with one of the other three.
A player successfully shoots the opponent (and wins the game) if they make the 'Fire' move at exactly the same time their opponent makes a 'Reload' move. Also, players can not fire the gun unless it has previously been loaded and they must reload before the each attempt at firing is made.
Once players have learnt the rules then it is best played as fast as possible. Keeping the rhythm whilst watching what your opponent is up to and deciding whether to attempt a shot or a reload become mind-bending at speed. And once you have mastered the basic game why not go for mental meltdown and play the the two arm version.
The video below should (hopefully) make clearer my description of this superb game.