Twenty questions

Twenty questions is a spoken parlor game which encourages deductive reasoning and creativity. The game dates to at least the eighteenth century and, during the twentieth century, was used as the basis for some radio and television quiz programs.

In the traditional game, the "answerer" chooses something that the other players, the "questioners", must guess. They take turns asking a question, which the answerer must answer with "yes" or "no". In variants of the game, answers such as "maybe" are allowed. Sample questions could be: "Is it bigger than a breadbox?", "Is it alive?", and finally "Is it this pen?". Lying is not allowed. If a questioner guesses the correct answer, they win and become the answerer for the next round. If 20 questions are asked without a correct guess, then the answerer has stumped the questioners and gets to be the answerer for another round.

Careful selection of questions can greatly improve the questioner's odds of winning the game. For example, a question such as "Does it involve technology for communications, entertainment, or work?" allows the questioner to cover a broad range of areas with a single question that can be answered with a simple "yes" or "no", significantly narrowing down the possibilities.

The early history of the game is unclear, but it appears to have been common by at least the 1780s, when the writer Hannah More recorded she and a friend had been "teaching ... the play of twenty questions" to an audience including Sir Joshua Reynolds and Lord North at a London dinner-party.