Brass Plaque on door at Tremedda farm, Zennor, Cornwall, England. It reads: TAKE NOTICE THAT AS FROM TODAYS DATE POACHERS SHALL BE SHOT ON FIRST SIGHT AND IF PRACTICABLE QUESTIONED AFTERWARDS. BY ORDER J.R. BRAMBLE HEAD GAMEKEEPER TO HIS GRACE THE DUKE OF GUMBY 1ST NOVEMBER 1868. Although the Duke of Gumby is probably a fictitious entity since there is no accessible record of him, the plaque may have had some deterrent effect
Robert Nares defined the word hoax as meaning "to cheat", dating from Thomas Ady's 1656 book A candle in the dark, or a treatise on the nature of witches and witchcraft.
The term hoax is occasionally used in reference to urban legends and rumors, but the folkloristJan Harold Brunvand argues that most of them lack evidence of deliberate creations of falsehood and are passed along in good faith by believers or as jokes, so the term should be used for only those with a probable conscious attempt to deceive. As for the closely related terms practical joke and prank, Brunvand states that although there are instances where they overlap, hoax tends to indicate "relatively complex and large-scale fabrications" and includes deceptions that go beyond the merely playful and "cause material loss or harm to the victim".
According to Professor Lynda Walsh of the University of Nevada, Reno, some hoaxes—such as the Great Stock Exchange Fraud of 1814, labeled as a hoax by contemporary commentators—are financial in nature, and successful hoaxers—such as P. T. Barnum, whose Fiji mermaid contributed to his wealth—often acquire monetary gain or fame through their fabrications, so the distinction between hoax and fraud is not necessarily clear. Alex Boese, the creator of the Museum of Hoaxes, states that the only distinction between them is the reaction of the public, because a fraud can be classified as a hoax when its method of acquiring financial gain creates a broad public impact or captures the imagination of the masses.
One of the earliest recorded media hoaxes is a fake almanac published by Jonathan Swift under the pseudonym of Isaac Bickerstaff in 1708. Swift predicted the death of John Partridge, one of the leading astrologers in England at that time, in the almanac and later issued an elegy on the day Partridge was supposed to have died. Partridge's reputation was damaged as a result and his astrological almanac was not published for the next six years.
It is possible to perpetrate a hoax by making only true statements using unfamiliar wording or context, such as in the Dihydrogen monoxide hoax. Political hoaxes are sometimes motivated by the desire to ridicule or besmirch opposing politicians or political institutions, often before elections.
A hoax differs from a magic trick or from fiction (books, movies, theatre, radio, television, etc.) in that the audience is unaware of being deceived, whereas in watching a magician perform an illusion the audience expects to be tricked.
A hoax is often intended as a practical joke or to cause embarrassment, or to provoke social or political change by raising people's awareness of something. It can also emerge from a marketing or advertising purpose. For example, to market a romantic comedy movie, a director staged a phony "incident" during a supposed wedding, which showed a bride and preacher getting knocked into a pool by a clumsy fall from a best man. A resulting video clip of Chloe and Keith's Wedding was uploaded to YouTube and was viewed by over 30 million people and the couple was interviewed by numerous talk shows. Viewers were deluded into thinking that it was an authentic clip of a real accident at a real wedding; but a story in USA Today in 2009 revealed it was a hoax.
A borderline case between fiction and hoax is a 1938 radio broadcast by Orson Welles describing a Martian invasion of earth. Many people who tuned in without hearing the introduction of the program as fiction were concerned that the invasion was real. It has been suggested that Welles knew the schedule of a popular program on another channel, and scheduled the first report of the invasion to coincide with a commercial break in the other program so that people switching stations would be tricked.
Governments sometimes spread false information to assist them with aims such as going to war; the "Iraq dossier" is an example of this; these often come under the heading of black propaganda. There is often a mixture of outright hoax and suppression and management of information to give the desired impression. In wartime and times of international tension rumours abound, some of which may be deliberate hoaxes.
Hoaxes perpetrated on occasions when their initiation is considered socially appropriate, such as April Fools' Day
Anthropologists were taken in by the "Piltdown Man discovery" that was widely believed from 1913 to 1953
Apocryphal claims that originate as a hoax gain widespread belief among members of a culture or organization, become entrenched as persons who believe it repeat it in good faith to others, and continue to command that belief after the hoax's originators have died or departed
Hoaxes formed by making minor or gradually increasing changes to a warning or other claim widely circulated for legitimate purposes
Hoaxes perpetrated by "scare tactics" appealing to the audience's subjectively rational belief that the expected cost of not believing the hoax (the cost if its assertions are true times the likelihood of their truth) outweighs the expected cost of believing the hoax (cost if false times likelihood of falsity), such as claims that a non-malicious but unfamiliar program on one's computer is malware
Computer virus hoaxes became widespread as viruses themselves began to spread. A typical hoax is an email message warning recipients of a non-existent threat, usually quoting spurious authorities such as Microsoft and IBM. In most cases the payload is an exhortation to distribute the message to everyone in the recipient's address book. Sometimes the hoax is more harmful, e.g., telling the recipient to seek a particular file (usually in a Microsoft Windowsoperating system); if the file is found, the computer is deemed to be infected unless it is deleted. In reality the file is one required by the operating system for correct functioning of the computer.
A hoax of exposure is a semi-comical or private sting operation. It usually encourages people to act foolishly or credulously by falling for patent nonsense that the hoaxer deliberately presents as reality. A related activity is culture jamming.
Rodney Marks, who describes himself as a corporate comedian, presents fake keynote speeches at business events. These speeches usually reveal the presenter as well informed about the conference and leading figures, but progressively the audience is lambasted until they recognize the comedy.