Mad Libs (a play on ad lib, from Latin ad libitum - as you wish) is a phrasal template word game where one player prompts another for a list of words to substitute for blanks in a story; these word substitutions have a humorous effect when the resulting story is then read aloud. The game is especially popular with American children and is frequently played as a party game or as a pastime. Mad Libs was invented in 1953 by Leonard Stern and Roger Price, who published the first Mad Libs book themselves in 1958.
Mad Libs books are still published by Price Stern Sloan, an imprint of Penguin Group, cofounded by Price and Stern. Mad Libs consist of a book that has a short story on each page, but with many of the key words replaced with blanks. Beneath each blank is specified a lexical or other category, such as noun, verb, place, or a part of the body.
One player asks the other players, in turn, to contribute some word for the specified type for each blank, but without revealing the context for that word. Finally, the completed story is read aloud. The result is usually comic, surreal and somewhat nonsensical.