# Liar's poker

Liar's poker is an American bar game that combines statistical reasoning with bluffing, and is played with the eight digits of the serial number on U.S. dollar bills. The digits are usually ranked with the 1 as "ace" as the highest value, followed by 0 as "10", down to 2 as the lowest. Each player holds one bill, unseen by the other players. The objective is to guess how often a particular digit appears among all the bills held by all the players. Each guess or bid must be higher in value or quantity than the previous bid. The round ends when all the other players challenge a bid.

## Gameplay

Usually the game is played with random bills obtained from the cash register. Each player takes a dollar bill and looks at its serial number without letting any other players see it. The starting player makes an opening bid on how many of a particular digit appears across all serial numbers held by the group. For example, if the first player bids three 6s, he is predicting there are at least three 6s among all the players including himself. The next player can bid a higher number at that level (three 7s), any number at a higher level (four 5s), or challenge the bid. The game continues clockwise around the table until a particular bid is challenged by every other player. If the challenge is correct, and the total number of the digit on all the bills is lower than the bid, the bidder loses a dollar to each of the other players. If the challenge is incorrect, the bidder wins a dollar.