In its original form, the confidence trickster tells his victim (the mark) that he is (or is in correspondence with) a wealthy person of high estate who has been imprisoned in Spain under a false identity. Some versions had the imprisoned person being an unknown or remote relative of the mark. Supposedly the prisoner cannot reveal his identity without serious repercussions, and is relying on a friend (the confidence trickster) to raise money to secure his release. In this classic pigeon drop game archetype, the confidence trickster offers to let the mark put up some of the funds, with a promise of a greater monetary reward upon release of the prisoner plus a non-pecuniary incentive, gaining the hand of a beautiful woman represented to be the prisoner's daughter. After the mark has turned over the funds, he is informed further difficulties have arisen, and more money is needed. With such explanations, the trickster continues to press for more money until the victim is cleaned out, or declines to put up more funds.
Key features of the Spanish Prisoner trick are the emphasis on secrecy and the trust the confidence trickster apparently places in the mark not to reveal the prisoner's identity or situation. The confidence trickster will typically claim to have chosen the mark carefully, based on his reputation for honesty and straight dealing, and may appear to structure the deal so that the confidence trickster's ultimate share of the reward will be distributed voluntarily by the mark.
- "AN OLD SWINDLE REVIVED.; The "Spanish Prisoner" and Buried Treasure Bait Again Being Offered to Unwary Americans". The New York Times. 20 March 1898. p. 12. Retrieved 2010-07-01.
- Shilling, Erik (2016-08-03). "The 9 Lives of the Spanish Prisoner, the Treasure-Dangling Scam That Won't Die". Atlas Obscura. Retrieved 2020-06-20.
- "100 Jahre alte Web-Phänomene Diese Netz-Hypes sind älter als das Internet". Spiegel Online, einestages feature (in German). Retrieved 17 April 2017.
- "The 100 Greatest Memes Ever". Thrillist. 2 August 2020. Retrieved 2020-06-20.
- Jorge Marco, 'The Spanish Swindle': Cartografía literaria trasnacional del timo del entierro, in Ignacio Mendiola and Daniel Oviedo (eds.), Relatos Infames: Breves historias de crimen y castigo (Barcelona: Anthropos, 2017)
- The Spanish Prisoner – original story by Arthur Train
- Metropolitan Police Service – Advance fee fraud
- Feb. 13, 1910: Fraud Letters Flood State Minneapolis Tribune newspaper article
- Examples of Spanish Prisoner letters