Bar bet
A bar bet is a bet made between two patrons at a bar. Bar bets can range from wagers about little-known trivia, such as obscure historical facts, to feats of skill and strength. Some bar bets are intended to trick the other party into losing. Enforceability. Under contract law, bar bets may or may not be legally binding, and the winning party may have difficulty having a court enforce the bet. A written contract, drawn up soberly the next day and signed by both parties, can avoid doubt. For example, if one or both parties are intoxicated  when the bet is made, they may be found to lack capacity to agree to a contract, and the contract thus found void or voidable. However, the fact that the agreement is oral but not written does not undermine it: oral contracts are valid, though certain contracts must be written, under the statute of frauds, such as for the transfer of land. Trick bets. In the UK in particular, bar bets are tricks which the "mark" cannot win. They usually depend upon a condition set in the bet that the mark doesn't notice. Some famous examples: Sometimes collectors  of bar bets will battle each other to see which one knows the most tricks. It is a given that each must accept the bet proposed by the other.