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

Scripts, such as MediaWiki, use magic words to make system information available to templates and editors, such as {{CURRENTTIME}} which displays the server time: 17:42

Examples of traditional magic words include:

• Abracadabra - prototypical magic word used by magicians
• Alakazam
• Hocus pocus - a phrase used by magicians (it can also refer to magic itself)
• Open sesame - used by the character Ali Baba in the English version of a tale from the collection popularly known as 1001 Arabian Nights (also used in a popular Bugs Bunny cartoon, "Ali Baba Bunny ")
• Presto chango - used by magicians (probably intended to suggest "quick change")
• Shazam - used by the comic book hero Captain Marvel

Note that the television game show You Bet Your Life, hosted by Groucho Marx in the 1950s, used the term secret word, not magic word. ("Say the secret word and win a prize!")

The term magic word is also used by adults to teach children politeness:

"Gimme ketchup!" "What's the magic word?" "Sorry. Can I have some ketchup please?"