Three-card Monte — also known as Find the Lady or the Three-card Trick — is a confidence game in which the victim, or mark, is tricked into betting a sum of money, on the assumption that they can find the money card among three face-down playing cards. It is the same as the shell game except that cards are used instead of shells.[1]
In its full form, Three-card Monte is an example of a classic "short con" in which a shill pretends to conspire with the mark to cheat the dealer, while in fact conspiring with the dealer to cheat the mark.
This confidence trick was already in use by the turn of the 15th century.[2]