A practical joke, or prank, is a mischievous trick played on someone, generally causing the victim to experience embarrassment, perplexity, confusion, or discomfort. A person who performs a practical joke is called a "practical joker". Other terms for practical jokes include gag, jape, or shenanigan.
Practical jokes differ from confidence tricks or hoaxes in that the victim finds out, or is let in on the joke, rather than being talked into handing over money or other valuables. Practical jokes are generally lighthearted and without lasting impact; they aim to make the victim feel humbled or foolish, but not victimized or humiliated. Thus most practical jokes are affectionate gestures of humour and designed to encourage laughter. However, practical jokes performed with cruelty can constitute bullying, whose intent is to harass or exclude rather than reinforce social bonds through ritual humbling.
A practical joke is "practical" because it consists of someone doing something physical, in contrast to a verbal or written joke. For example, the joker who is setting up and conducting the practical joke might hang a bucket of water above a doorway and rig the bucket using pulleys so when the door opens the bucket dumps the water. The joker would then wait for the victim to walk through the doorway and be drenched by the bucket of water. Objects can also be used in practical jokes, like fake vomit, chewing gum bugs, exploding cigars, stink bombs, costumes and whoopee cushions.
Practical jokes often occur inside offices, usually to surprise co-workers. Covering the computer accessories with Jell-O, wrapping the desk with Christmas paper or aluminium foil or filling it with balloons are just some examples of office pranks. Practical jokes are also common occurrences during sleepovers, whereby teens will play pranks on their friends as they come into the home, enter a room or even as they sleep.
American humorist H. Allen Smith wrote a 320-page book in 1953 called The Compleat Practical Joker (ISBN 0-688-03705-4) that contains numerous examples of practical jokes. The book became a best seller not only in the United States but also in Japan.Moira Marsh has written an entire volume about practical jokes One of her findings is that in the USA they are more often done by males than females.