Players sit around a table. There is a secret rule and the aim of those who don’t know it is to discover this rule.
There are only three responses that are allowed: "One Up, One Down", "Two Up", "Two Down" No questions are actually asked, players must simply give one of the three allowable responses when
it is their turn. Play begins with a player who already knows the rule, giving one of the three responses. The next player must now give one of the three responses. Then the player(s) who know
the rule inform whether the response was “correct” or “incorrect”, and the play moves on to the next player.
The secret to the game is that response must match the position of the player’s arms relative to the table. "One Up, One Down" is correct when they have one arm on the table and one off the
table. "Two Up" is correct when they have both arms on the table. "Two Down" is correct when they have both arms off of the table.
In a drinking version of the game, every time a player gives an incorrect response, they must take a drink. So simple yet so aggravating when you don't have a clue.