Muphry's law is an adage that states: "If you write anything criticizing editing or proofreading, there will be a fault of some kind in what you have written." The name is a deliberate misspelling of Murphy's law.
Similar laws have also been coined, usually in the context of online communication, under names including Skitt's Law, Hartman's Law of Prescriptivist Retaliation (or The Law of Prescriptive Retaliation), The Iron Law of Nitpicking, and McKean's Law. Further variations state that flaws in a printed or published work will only be discovered after it is printed and not during proofreading, and flaws such as spelling errors in a sent email will be discovered by the sender only during rereading from the "Sent" box.
John Bangsund of the Society of Editors (Victoria) in Australia identified Muphry's law as "the editorial application of the better-known Murphy's law" and set it down in 1992 in the Society of Editors Newsletter.
The law, as set out by Bangsund, states that:
(a) if you write anything criticizing editing or proofreading, there will be a fault of some kind in what you have written;
(b) if an author thanks you in a book for your editing or proofreading, there will be mistakes in the book;
(c) the stronger the sentiment expressed in (a) and (b), the greater the fault;
(d) any book devoted to editing or style will be internally inconsistent.
It goes on to say:
Muphry's Law also dictates that, if a mistake is as plain as the nose on your face, everyone can see it but you. Your readers will always notice errors in a title, in headings, in the first paragraph of anything, and in the top lines of a new page. These are the very places where authors, editors and proofreaders are most likely to make mistakes.
Muphry's law may be interpreted to be in accordance to a previous quote from Ambrose Bierce:
In neither taste nor precision is any man's practice a court of last appeal, for writers all, both great and small, are habitual sinners against the light; and their accuser is cheerfully aware that his own work will supply (as in making this book it has supplied) many "awful examples". ("Write it Right: A Little Blacklist of Literary Faults" 1909)
Stephen J. Dubner described learning of the existence of Muphry's law in the Freakonomics section of The New York Times in July 2008. He had accused The Economist of a typo in referring to Cornish pasties being on sale in Mexico, assuming that "pastries" had been intended and being familiar only with the word "pasties" with the meaning of nipple coverings. A reader had alerted him to the existence of the law, and The Economist had responded by sending Dubner a Cornish pasty.
In 2009, the then British Prime Minister Gordon Brown hand-wrote a letter of condolence to a mother whose son had died in Afghanistan, during which he misspelled the deceased's surname. The Sun (a tabloid newspaper) published a vitriolic article criticising his lack of care. In this article, the paper misspelled the same name and was forced to publish an apology of its own.
- Bangsund, John (March 1992). "Scenes of editorial life: Muphry's law". John Bangsund's Threepenny Planet. Retrieved 2008-07-18.
- Liberman, Mark (April 4, 2005). "Hartman's Law Confirmed Again". Language Log. Retrieved 2009-02-13.
- "Discussion Forums | Phrase confused". Wordorigins.org. Retrieved 2011-12-13.
- Liberman, Mark (2006-04-26). "Language Log: Who is the decider?". Itre.cis.upenn.edu. Retrieved 2011-12-13.
- Quinion, Michael (10 November 2001). "Verbatim". World Wide Words newsletter (596). Retrieved 2009-10-19. "Erin McKean described what she calls McKean’s Law: "Any correction of the speech or writing of others will contain at least one grammatical, spelling, or typographical error.""
- Bloch, Arthur (May 18, 2000). Murphy's Law: Lawyers: Wronging the Rights in the Legal Profession!. PSS Adult. ISBN 0-8431-7580-X.
- "Muphry's law". Canberra Society of Editors newsletter. November 2003. Retrieved 2008-07-18.
- Mackenzie, Janet (2004). The Editor's Companion. Cambridge University Press. p. 123. ISBN 0-521-60569-5. Retrieved 2008-07-19.
- Zimmer, Benjamin (2005-11-12). "Bierce's law?". Language Log. Retrieved 2008-07-19.
- Dubner, Stephen J. (2008-07-15). "Pasties, Pasties, Everywhere". The New York Times: Freakonomics. Retrieved 2008-07-21.
- "Very humble pie for the Sun". twitpic. 13 November 2009. Retrieved 2009-11-23.
- Sweney, Mark (13 November 2009). "Sun apologises for misspelling name of soldier's mother on website". The Guardian. Retrieved 2009-11-23.