# Coin-matching game

A coin-matching game (also a coin smack[1] or smack game[2]) is a confidence trick in which two con artists set up one victim.

The first con artist strikes up a conversation with the victim, usually while waiting somewhere. The con artist suggests matching pennies (or other coins) to pass the time. The second con artist arrives and joins in, but soon leaves for a moment. The first con artist then suggests cheating. The victim, thinking they are going to scam the second con artist, agrees to match coins each time.

When the second con artist returns and begins losing, he accuses the two of cheating and threatens to call the police. The first con artist offers a sizable sum of hush money, and the victim contributes something too. After the victim leaves, the two con artists split up the money extorted from the victim.[3]

In game theory the term refers to a zero-sum two-person game of imperfect information (not involving a third player or collusion);[4][5][6] other variations on the name are "matching coins" or "matching pennies".[7][8]

## References

1. ^ Porter, Thomas J. Jr. (November 28, 1969). Con Artists Show Diversified Skills. Pittsburgh Post-Gazette
2. ^ Associated Press (January 11, 1963). 3 sentenced; they picked wrong man. The Spokesman-Review
3. ^ Staff report (November 9, 1913). Coin matchers of Times Square are doing rushing business; Detective Says He Knows No Less than 100 Professionals in That Line, Who Feel Safe Because Few Ever Get "Sent Up." The New York Times
4. ^ Robert Clarke James; Glenn James (1992). Mathematics dictionary. Springer. p. 180. ISBN 978-0-412-99041-0.
5. ^ Soo Tang Tan (2005). Finite mathematics for the managerial, life, and social sciences. Cengage Learning. p. 543. ISBN 978-0-534-49214-4.
6. ^ Herman Chernoff; Lincoln E. Moses (1959). Elementary decision theory. Courier Dover Publications. p. 346. ISBN 978-0-486-65218-4.
7. ^ Peter Morris (1994). Introduction to game theory. Springer. p. 11. ISBN 978-0-387-94284-1.
8. ^ Julio González-Díaz; Ignacio García-Jurado; M. Gloria Fiestras-Janeiro (2010). An Introductory Course on Mathematical Game Theory. AMS Bookstore. p. 29. ISBN 978-0-8218-5151-7.