Magic words are words which have a specific, and sometimes unintended, effect. They are often nonsense phrases used in fantasy fiction or by stage prestidigitators. Certain comic book heroes use magic words to activate their super powers. Magic words are also used as Easter eggs or cheats in computer games, other software, and operating systems. (For example, the words xyzzy, plugh, and plover were magic words in the classic computer adventure game Colossal Cave Adventure).