The details vary, but the usual story is that a person, often a government or bank employee, knows of a large amount of unclaimed money or gold which he cannot access directly, usually because he has no right to it.Such people, who may be real but impersonated people or fictitious characters played by the con artist, could include, for example, the wife or son of a deposed African leader who has amassed a stolen fortune, a bank employee who knows of a terminally ill wealthy person with no relatives, or a wealthy foreigner who deposited money in the bank just before dying in a plane crash (leaving no will or known next of kin), and similar characters.One variant of the scam may date back to the 18th or 19th centuries, as a very similar letter, entitled "The Letter from Jerusalem", is seen in the memoirs of Eugène François Vidocq, a former French criminal and private investigator. One of these, sent via postal mail, was addressed to a woman's husband, and inquired about his health.
The scam has been used with fax and traditional mail, and is now prevalent in online communications like emails.
Online versions of the scam originate primarily in the United States, the United Kingdom and Nigeria, with Ivory Coast, Togo, South Africa, Benin, the Netherlands, and Spain also having high incidences of such fraud.
The money could be in the form of gold bullion, gold dust, money in a bank account, blood diamonds, a series of checks or bank drafts, and so forth.
The sums involved are usually in the millions of dollars, and the investor is promised a large share, typically ten to forty percent, in return for assisting the fraudster to retrieve or expatriate the money.
The scam messages often claim to originate in Nigeria, but usually this is not true.
The number "419" refers to the section of the Nigerian Criminal Code dealing with fraud, the charges and penalties for offenders.
According to Cormac Herley, a researcher for Microsoft, "By sending an email that repels all but the most gullible, the scammer gets the most promising marks to self-select." In Nigeria, scammers use computers in Internet cafés to send mass emails promising potential victims riches or romance, and to trawl for replies.
They refer to their targets as Magas, slang developed from a Yoruba word meaning "fool".
In exchange for transferring the funds out of Nigeria, the recipient would keep 30% of the total.