A practical joke or prank is a humorous practice in which another person is fooled, annoyed, or embarrassed in what the perpetrator imagines to be a mild and light-hearted fashion. Some types of practical jokes include:

• hoaxes, especially ones perpetrated on or by the media (See also: culture jamming).
• physical types of practical jokes, such as causing someone to:
  • trip,
  • get wet (ex: using water-filled balloons),
  • unknowingly wear embarrassing signs (ex: a 'kick me' note on the back),
  • get soiled (saran wrap on the toilet seat) or
  • produce unpleasant sounds (ex: a whoopee cushion[?])
• forms of mild harassment (ex: soaping someone's windows, decorating their yard with toilet paper, sending them on a snipe hunt).

Practical jokes are features of various kinds of holidays, such as April Fool's Day, Halloween, and in Spanish-speaking cultures the Day of the Holy Innocents. They also feature in various rites of passage, such as stag nights[?].

see also: joke, prank, humour, sadism, laughter, hack (MIT student pranks)