Twenty Questions is a spoken parlor game which encourages deductive reasoning and creativity. It originated in the United States and was played widely in the 19th century. It escalated in popularity during the late 1940s when it became the format for a successful weekly radio quiz program.
In the traditional game, one player is chosen to be the answerer. That person chooses a subject (object) but does not reveal this to the others. All other players are questioners. They each take turns asking a question which can be answered with a simple "Yes" or "No." In variants of the game (see below), multiple state answers may be included such as the answer "Maybe." The answerer answers each question in turn. Sample questions could be: "Is it bigger than a breadbox?" or "Can I put it in my mouth?" Lying is not allowed in the game. If a questioner guesses the correct answer, that questioner wins and becomes 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 odds of the questioner winning the game. For example, a question such as "Does it involve technology for communications, entertainment or work?" can allow the questioner to cover a broad range of areas using a single question that can be answered with a simple "yes" or "no". If the answerer responds with "yes," the questioner can use the next question to narrow down the answer; if the answerer responds with "no," the questioner has successfully eliminated a number of possibilities for the answer.
Popular variants 
The most popular variant is called "Animal, Vegetable, Mineral." This is taken from the Linnaean taxonomy of the natural world. In this version, the answerer tells the questioners at the start of the game whether the subject belongs to the animal, vegetable or mineral kingdom. These categories can produce odd technicalities, such as a wooden table being classified as a vegetable (since wood comes from trees), or a belt being both animal and mineral (because its leather comes from the hide of an animal unless it is synthetic, and its buckle is made of metal).
Other versions specify that the item to be guessed should be in a given category, such as actions, occupations, famous people, etc. In Hungary, a similar game is named after Simon bar Kokhba. A version of Twenty Questions called Yes and No is played as a parlour game by characters of Charles Dickens' A Christmas Carol.
In another version, the answerer claims to have a story in mind and the questioners are to attempt to obtain and retell the story via twenty questions. But, without the questioners' knowing, the answerer actually has no story in mind, and answers the questions "yes" or "no" according to some set rule, such as whether the question ends in a vowel or consonant (and "maybe" if the question ends in "y"). After the twenty questions the questioners try to retell the story according to the answers, which results in laughs for everyone.
Computers, scientific method and situation puzzles 
The game suggests that the information (as measured by Shannon's entropy statistic) required to identify an arbitrary object is at most 20 bits. The game is often used as an example when teaching people about information theory. Mathematically, if each question is structured to eliminate half the objects, 20 questions will allow the questioner to distinguish between 220 or 1,048,576 objects. Accordingly, the most effective strategy for Twenty Questions is to ask questions that will split the field of remaining possibilities roughly in half each time. The process is analogous to a binary search algorithm in computer science or successive approximation ADC in analog-to-digital signal conversion.
In 1901 Charles Sanders Peirce discussed factors in the economy of research that govern the selection of a hypothesis for trial — (1) cheapness, (2) intrinsic value (instinctive naturalness and reasoned likelihood), and (3) relation (caution, breadth, and incomplexity) to other projects (other hypotheses and inquiries). He discussed the potential of Twenty Questions to single one subject out from among 220 and, pointing to skillful caution, said,
Thus twenty skillful hypotheses will ascertain what two hundred thousand stupid ones might fail to do. The secret of the business lies in the caution which breaks a hypothesis up into its smallest logical components, and only risks one of them at a time.
He elaborated on how, if that principle had been followed in the investigation of light, its investigators would have saved themselves from half a century of work. Note that testing the smallest logical components of a hypothesis one at a time does not mean asking about, say, 1,048,576 subjects one at a time. Instead it means extracting aspects of a guess or hypothesis, and asking, for example, "did an animal do this?" before asking "did a horse do this?".
That aspect of scientific method resembles also a situation puzzle in facing (unlike Twenty Questions) a puzzling scenario at the start. Both games involve asking yes/no questions, but Twenty Questions places a greater premium on efficiency of questioning. A limit on their likeness to the scientific process of trying hypotheses is that a hypothesis, because of its scope, can be harder to test for truth (test for a "yes") than to test for falsity (test for a "no") or vice versa (see Falsifiability).
In the 1940s the game became a popular radio panel quiz show, Twenty Questions, first broadcast at 8pm, Saturday, February 2, 1946, on the Mutual Broadcasting System from New York's Longacre Theatre on West 48th Street. Radio listeners sent in subjects for the panelists to guess in 20 questions; Winston Churchill's cigar was the subject most frequently submitted. On the early shows, listeners who stumped the panel won a lifetime subscription to Pageant. From 1946 to 1951, the program was sponsored by Ronson Lighters. In 1952-53, Wildroot Cream-Oil was the sponsor.
The show was the creation of Fred Van Deventer, who was born December 5, 1903 in Tipton, Indiana, and died December 2, 1971. Van Deventer was a WOR Radio newscaster with New York's highest-rated news show, Van Deventer and the News. Van Deventer was on the program's panel with his wife, Florence Van Deventer, who used her maiden name, appearing on the show as Florence Rinard. Their 14-year-old son, Robert Van Deventer (known on the show as Bobby McGuire) and the program's producer, Herb Polesie, completed the regular panel with daughter Nancy Van Deventer joining the group on occasions. Celebrity guests sometimes contribute to identifying the subject at hand.
The Van Deventer family had played the game for years at their home, long before they brought the game to radio, and they were so expert at it that they could often nail the answer after only six or seven questions. On one memorable show, Maguire succeeded in giving the correct answer (Brooklyn) without asking a single question. The studio audience was shown the answer in advance and Maguire based his answer on the audience's reaction; during the 1940s, New York radio studio audiences included many Brooklynites, and they cheered wildly whenever Brooklyn was mentioned in any context.
The moderator was sportscaster Bill Slater who opened each session by giving the clue as animal, vegetable, or mineral. He then answered each query from panel members. This cast remained largely intact throughout the decade-long run of the show. Slater was succeeded at the beginning of 1953 by Jay Jackson, who remained through the final broadcast, and there were two changes in the panel's juvenile chair. When McGuire graduated from high school, his decision to attend the North Carolina-based Duke University meant he could no longer remain on the program, so he asked his high school friend Johnny McPhee to replace him. Since McPhee was attending nearby Princeton University, he was thus geographically available for the production in New York. McPhee continued until he graduated and was himself succeeded by Dick Harrison (real name John Beebe) in September 1953. Harrison continued until early 1954, when he was replaced by Bobby McGuire, then 22 years old. McGuire appeared as the "oldest living teenager" until the end of the run.
|Created by||Fred van de Venter (1949-1955)
Ron Greenberg by arrangement with Dick Rubin Ltd (1975 Pilot)
|Directed by||Roger Bower (1949-1955)
Dick Sandwick (1949-1955)
Harry Coyle (1949-1955)
Arthur Forrest (1975 Pilot)
|Presented by||Bill Slater (1949–1952)
Jay Jackson (1952–1955)
Jack Clark (1975 Pilot)
Dick Wilson (1989 Pilot)
|Narrated by||Frank Waldecker (1949-1955)
John Gregson (1949-1955)
Bob Shepard (1949-1955)
Wayne Gossman (1975 Pilot)
Burton Richardson (1989 Pilot)
|Composer(s)||Score Productions (1975 Pilot)|
|Country of origin||United States|
|No. of seasons||6|
|Executive producer(s)||Fred van de Venter (1949-1955)
Ron Greenberg (1975 Pilot)
|Producer(s)||Norman Livingston (1949-1955)
Jack Wyatt (1949-1955)
Duane McKinney (1949-1955)
George Elber (1949-1955)
Gary Stevens (1949-1955)
|Location(s)||New Amsterdam Theatre, New York (1949-1955)
ABC Television Center, New York (1975 Pilot)
KTLA Studios, Hollywood (1989 Pilot)
|Running time||25 mins.|
|Production company(s)||Fred van de Venter Productions (1949-1955)
Mutual Broadcasting System (1949-1955)
Ron Greenberg Productions (1975 Pilot)
MCA-TV Ltd (1975 Pilot)
|Distributor||Buena Vista Television (1989 Pilot)|
|Original channel||WOR (1949)
ABC (1950–1951, 1954–1955)
|Picture format||Black-and-white (1949-1955)
Color (1975 Pilot, 1989 Pilot)
|Original run||November 2, 1949– May 3, 1955|
|Related shows||20Q (2009)|
As a television series, Twenty Questions debuted as a local show in New York on WOR-TV Channel 9 on November 2, 1949. Beginning on November 26, the series went nationwide on NBC until December 24, after which it remained dormant until March 17, 1950 when it was picked up by ABC until June 29, 1951.
Its longest and most well-known run, however, is the one on the DuMont Television Network from July 6, 1951 to May 30, 1954. During this time, original host Bill Slater was replaced by Jay Jackson. After this run ended, ABC picked up the series once again from July 6, 1954 to May 3, 1955. The last radio show had been broadcast on March 27, 1954.
In 1975, producer Ron Greenberg made a pilot for a revival on ABC with host Jack Clark, which did not sell. The pilot featured four celebrities; actress Kelly Garrett, movie critic Gene Shalit, commedianne Anne Meara, and actor Tony Roberts, along with two contestants who competed against each other.
Each contestant joined the panel, one at a time, to earn a $500 jackpot for themselves by identify subjects from three categories chosen out of five. Any panelist can guess the subject at any time at the risk of using a question. After every five questions asked the at stakes money is reduced. The panel is then given a clue and a fifteen second conference. Afterward, the contestant is then given a free guess of the subject with the risk of giving their opponent a chance to guess and steal the pot. If the guesses are incorrect the money is reduced again and more questions are then asked. The third round features both contestants on a toss-up basis and the panelists asking questions without being allowed to guess the subject.
The contestant with the most money won the game, then rejoined the panel for a bonus game. To win a $5,000 pot, the panel asks as many questions as possible within a sixty second time limit. The player can buzz in an anytime to stop the clock and receive one of three clues, one clue at a time, in exchange for losing half the bonus pot.
Episode status 
Like many game shows of the era, Twenty Questions was a victim of wiping. A DuMont episode from January 18, 1952 and the 1975 pilot circulate among collectors. It is unknown how many radio episodes survive.
Versions outside the US 
Twenty Questions also appeared in several other countries.
United Kingdom 
The BBC aired a version on radio from 28 February 1947 to 1976 with TV specials airing in 1947 and 1948 plus a series from 1956-1957. On radio, the subject to be guessed was revealed to the audience by a "mystery voice" (originally Norman Hackforth from 1947-1962; he was later a regular panelist). Hackforth became well-known amongst the British public as much for his aloofness as his apparent knowledgeability.
The series was originally presented by Stewart MacPherson. A later presenter, Gilbert Harding, was ousted in 1960 by producer Ian Messiter when, after having drunk a triple gin-and-tonic he had originally offered to Messiter, he proceeded to completely ruin the night's game – he insulted two panelists, failed to recognise a correct identification after seven questions (after revealing the answer upon the 20th question, he yelled at the panel and audience), and ended the show three minutes early by saying "I'm fed up with this idiotic game ... I'm going home"). He was replaced by Kenneth Horne until 1967, followed by David Franklin from 1970-1972.
A revival ran for one season in the 1990s on BBC Radio 4, hosted by Jeremy Beadle. A version with a rival line-up, produced by commercial station Radio Luxembourg, is not acknowledged by the BBC.
A televised version ran from 1960-1961, produced by Associated-Rediffusion for ITV and hosted by Peter Jones (who later hosted in 1974). The "mystery voice" later became a running gag on the radio series I'm Sorry I Haven't A Clue.
A bi-lingual (Irish/English) version of Twenty Questions aired on RTE Radio 1 in the 1960s and '70s. It was hosted by Gearóid Ó Tighearnaigh and produced by Bill O'Donovan and included Dominic O’Riordan, Tony Ó Dálaigh, Seán Ó Murchú and Máire Noone (the only woman) on the panel. It proved enormously popular, travelling the length and breadth of Ireland, hosted in local clubs and community halls. Photo of the Quiz team. Featured article in the RTE Guide 1 November 1968. An 8 minute bi-lingual extract of a 1971 broadcast can be heard by clicking here
NRK aired its own version continuously from 1947 to the early 1980s. In 2004, the radio series was revived and regained its popularity, leading to a 2006 TV version. The Norwegian 20 spørsmål continues on NRK radio and TV, and a web-based game is available at the official NRK website. A 2006 board game based on the series is currently the prize sent to listeners who beat the panel.
In Hungary, this game is popularly known as "barkochba", named after Simon bar Kokhba, the leader of the second century Jewish uprising against the Romans. The story goes that the Romans cut out his spy's tongue, so when he reached bar Kokhba's camp, he was able to nod or shake his head only to answer bar Kokhba's questions. The game is not usually played in the media, but at parties, and it is widely known since at least 1922, first invented sometime after 1900, see http://hu.wikipedia.org/wiki/Barkochba. The number of questions is not limited to twenty.
See also 
- Tactics of 20 Questions Rules and Tactics
- 20 Questions Play the game online
- 20Q artificial intelligence
- Guess Who? board game
- List of programs broadcast by the DuMont Television Network
- List of surviving DuMont Television Network broadcasts
- 1950-51 United States network television schedule (ABC, Fridays at 8pm ET)
- 1951-52 United States network television schedule (DuMont, Fridays at 10pm ET)
- 1952-53 United States network television schedule (DuMont, Fridays at 10pm ET)
- 1953-54 United States network television schedule (DuMont, Mondays at 8pm ET)
- 1954-55 United States network television schedule (ABC, Tuesdays at 8:30pm ET)
- Situation puzzle
- Akinator, the Web Genius, an on-line version which uses artificial intelligence.
- David Weinstein, The Forgotten Network: DuMont and the Birth of American Television (Philadelphia: Temple University Press, 2004) ISBN 1-59213-245-6
- Alex McNeil, Total Television, Fourth edition (New York: Penguin Books, 1980) ISBN 0-14-024916-8
- Tim Brooks and Earle Marsh, The Complete Directory to Prime Time Network TV Shows, Third edition (New York: Ballantine Books, 1964) ISBN 0-345-31864-1
- David Schwartz, Steve Ryan and Fred Wostbrock, The Encyclopedia of TV Game Shows, Third edition (New York: Checkmark Books, 1999) ISBN 0-8160-3847-3
- Walsorth, Mansfield Tracy. Twenty questions: a short treatise on the game, Holt, 1882
- Peirce, C. S. (1901 MS), "On The Logic of Drawing History from Ancient Documents, Especially from Testimonies," manuscript corresponding to an abstract delivered at the National Academy of Sciences meeting of November 1901. Published in 1958 in Collected Papers v. 7, paragraphs 162–231; see 220. Reprinted (first half) in 1998 in The Essential Peirce v. 2, pp. 75–114; see 107–110.
- "A Letter From The Publisher: Nov. 23, 1962". Time. 1962-11-23. ISSN 0040-718X. Retrieved 2008-09-18.
- "Obituary: Norman Hackforth". The Independent. 1996-12-18. Retrieved 2009-08-26.
- UK Game Shows: "20 Questions"
- David Kynaston (2008). Austerity Britain 1945–51. Bloomsbury. p. 583. ISBN 978-0-7475-9923-4.
- "NRK". Nrk.no. 2009-06-20. Retrieved 2009-07-25.