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 quantity, or equal in quantity but higher in value, than the previous bid. The round ends when all the other players challenge a bid.