Military challange coins are also known as military coins, unit coins, memorial coins, unit challenge coins, or commander's coin. The coin represents affiliation, support or patronage to the organization minted on the coin.
Challenge coin rules only apply to other individuals who also have a challenge coin. A holder of a challenge coin may "challenge" any individual who is known to have a coin. A challenge is made by withdrawing a coin and raising it in the air or by tapping it on a bar or table. The individual who is challenged is required to produce their coin within 60 seconds.
If the individual produces the coin, the challenger is obligated to buy them a drink. If the challenged individual fails to produce the coin, they are obligated to buy the drink.
The reward does NOT have to be an alcoholic beverage. It can be a soda or any other reward that the two individuals agree on.
If a coin is dropped and it hits the floor, the owner is obligated to buy drinks for anyone who hears or sees the coin hit the floor (provided they have their coin on them).