You are the Guesser being evaluated in a Twenty Questions benchmark. One subject is hidden. The initial BEGIN message provides its broad category as trusted game metadata. Identify the subject using as few counted questions as possible. ASK is only for learning a property that helps distinguish possible candidates. Never use ASK to confirm a named candidate or ask whether the subject is a specific identity. When you are ready to name a candidate, use GUESS immediately. A correct GUESS costs zero counted questions; an incorrect GUESS costs exactly one, the same as ASK. A GUESS must provide both a name and a short identifying description. The engine replies only YES, NO, or UNKNOWN; UNKNOWN is a valid answer meaning the factual adjudication system could not determine the proposition under its evidence policy. Questions requiring proof of absence, exclusivity, completeness, exact counts, or subjective classification are more likely to return UNKNOWN. Prefer direct, positively verifiable properties when possible. The initial BEGIN event includes an opaque variation_token that contains no information about the hidden subject. Do not interpret, repeat, mention, or derive meaning from it. After BEGIN, each user reply is either one adjudicated YES, NO, or UNKNOWN token or a fixed FORMAT_ERROR event. FORMAT_ERROR means your immediately preceding response did not match the required structured-action contract, was not semantically adjudicated, and consumed one counted turn. Use the formats in that event and try again. Never infer that the attempted question or guess was right or wrong. At most 50 questions or rejected guesses are counted. After that limit you receive one final guess-only opportunity. Format errors also consume counted turns. The provider wire response is an object with exactly one `result` action. On the final opportunity ASK is forbidden. Return only the required structured response. Do not include analysis, hidden reasoning, or additional fields.
- Questions
- 20
- Outcome
- Solved
- Format errors
- Errors found View one example
- Duration
- 8m 5s
- Round cost
- $0.2808 All 21 turns
Format warning
The model sent replies in the wrong format.
The Guesser sent 1 invalid reply. Each one before the question limit used up a counted turn. The model was only reminded of the required format; it was never told whether its question or guess was correct.
- Valid format
- 95.2%
- Format errors
- 1
- Turns used by format errors
- 1
Transcript
Questions and answers.
Turns are shown in the order they happened. Each shows the Guesser's question or guess, then the final checked answer.
Exact Guesser setupSystem message and BEGIN event
The Guesser received these messages at the start of the round. The BEGIN message holds the broad category and a code made from the base seed and round number, which reveals nothing about the subject.
{"category":"person","event":"BEGIN","variation_token":"BYOMPCJW"}Valid replies are shown in the required format. Rejected replies are shown separately, without provider or call IDs.
Is this person currently alive?
Recorded Guesser outputRequired JSON format
{"result":{"action":"ASK","description":null,"name":null,"question":"Is this person currently alive?"}}Oracle evidence2 model-reported sources
The Oracle reported these excerpts and URLs. They are not independently checked.
The Institute Season Two — Posted: February 4th, 2026 ... Production has begun on The Institute Season 2 at MGMOpen stephenking.com (opens in a new tab)
Stephen King ... Posted: February 9th, 2026 ... Stephen tells Esquire about Other Worlds Than TheseOpen stephenking.com (opens in a new tab)
Is this person primarily known for work in entertainment (acting, music, or similar)?
Recorded Guesser outputRequired JSON format
{"result":{"action":"ASK","description":null,"name":null,"question":"Is this person primarily known for work in entertainment (acting, music, or similar)?"}}Oracle evidence2 model-reported sources
The Oracle reported these excerpts and URLs. They are not independently checked.
Stephen (Edwin) King ... U.S. writer of horror stories ... one of the world’s best-selling writers.Open britannica.com (opens in a new tab)
Stephen King ... American novelist and short-story writer ... established King’s reputation as a master of horror literature.Open kids.britannica.com (opens in a new tab)
Is this person primarily known for politics or government?
Recorded Guesser outputRequired JSON format
{"result":{"action":"ASK","description":null,"name":null,"question":"Is this person primarily known for politics or government?"}}Oracle evidence2 model-reported sources
The Oracle reported these excerpts and URLs. They are not independently checked.
He is best known for his works in the horror and fantasy genres.Open cnn.com (opens in a new tab)
U.S. writer of horror stories.Open britannica.com (opens in a new tab)
Reply in the wrong format.
Invalid action · fixed format reminder sent
Why this reply was rejectedInvalid action · turn 4
The reply was JSON, but it matched neither the ASK nor the GUESS format.
- Recorded type
invalid_action- Turn
- 4
- Counted
- Yes · question 4
- Feedback
- FORMAT_ERROR
{"result":{"action":"ASK","description":null,"name":null,"question":"Is this person primarily known for sports?"},"_dummy":null}{"result":{"action":"ASK","description":null,"name":null,"question":"<non-empty yes-or-no property question>"}}{"result":{"action":"GUESS","description":"<non-empty identifying description>","name":"<non-empty candidate name>","question":null}} A reply must match one of these formats exactly. Text fields in use must not be empty; unused fields must be JSON null.
Is this person primarily known for sports or athletics?
Recorded Guesser outputRequired JSON format
{"result":{"action":"ASK","description":null,"name":null,"question":"Is this person primarily known for sports or athletics?"}}Oracle evidence2 model-reported sources
The Oracle reported these excerpts and URLs. They are not independently checked.
Best-selling author Stephen King ... is best known for his works in the horror and fantasy genres.Open cnn.com (opens in a new tab)
Stephen (Edwin) King ... U.S. writer of horror stories.Open britannica.com (opens in a new tab)
Is this person primarily known for science, technology, or computing?
Recorded Guesser outputRequired JSON format
{"result":{"action":"ASK","description":null,"name":null,"question":"Is this person primarily known for science, technology, or computing?"}}Oracle evidence2 model-reported sources
The Oracle reported these excerpts and URLs. They are not independently checked.
U.S. writer of horror stories... one of the world’s best-selling writers.Open britannica.com (opens in a new tab)
He is best known for his works in the horror and fantasy genres.Open cnn.com (opens in a new tab)
Is this person primarily known for business or entrepreneurship?
Recorded Guesser outputRequired JSON format
{"result":{"action":"ASK","description":null,"name":null,"question":"Is this person primarily known for business or entrepreneurship?"}}Oracle evidence1 model-reported source
The Oracle reported these excerpts and URLs. They are not independently checked.
U.S. writer of horror stories ... one of the world’s best-selling writers.Open britannica.com (opens in a new tab)
Is this person primarily known for writing or literature?
Recorded Guesser outputRequired JSON format
{"result":{"action":"ASK","description":null,"name":null,"question":"Is this person primarily known for writing or literature?"}}Oracle evidence2 model-reported sources
The Oracle reported these excerpts and URLs. They are not independently checked.
U.S. writer of horror stories... one of the world’s best-selling writers.Open britannica.com (opens in a new tab)
American novelist and short-story writer Stephen King... helped to establish King’s reputation as a master of horror literature.Open kids.britannica.com (opens in a new tab)
Is this person primarily known as a fiction writer or novelist?
Recorded Guesser outputRequired JSON format
{"result":{"action":"ASK","description":null,"name":null,"question":"Is this person primarily known as a fiction writer or novelist?"}}Oracle evidence1 model-reported source
The Oracle reported these excerpts and URLs. They are not independently checked.
Stephen King is an American novelist and short-story writer whose books are credited with reviving the horror fiction genre.Open britannica.com (opens in a new tab)
Is this person known for writing fantasy or science fiction?
Recorded Guesser outputRequired JSON format
{"result":{"action":"ASK","description":null,"name":null,"question":"Is this person known for writing fantasy or science fiction?"}}Oracle evidence2 model-reported sources
The Oracle reported these excerpts and URLs. They are not independently checked.
His books blend horror, the macabre, fantasy, and science fiction.Open britannica.com (opens in a new tab)
Stephen King is an American author of contemporary horror, thriller, science fiction, and fantasy.Open en.wikipedia.org (opens in a new tab)
Is this person American?
Recorded Guesser outputRequired JSON format
{"result":{"action":"ASK","description":null,"name":null,"question":"Is this person American?"}}Oracle evidence1 model-reported source
The Oracle reported these excerpts and URLs. They are not independently checked.
Stephen (Edwin) King ... (born Sept. 21, 1947, Portland, Maine, U.S.), U.S. writer of horror stories.Open britannica.com (opens in a new tab)
Is this person known for writing fantasy specifically rather than science fiction?
Recorded Guesser outputRequired JSON format
{"result":{"action":"ASK","description":null,"name":null,"question":"Is this person known for writing fantasy specifically rather than science fiction?"}}Is this person male?
Recorded Guesser outputRequired JSON format
{"result":{"action":"ASK","description":null,"name":null,"question":"Is this person male?"}}Oracle evidence1 model-reported source
The Oracle reported these excerpts and URLs. They are not independently checked.
Stephen King ... Gender: MaleOpen nndb.com (opens in a new tab)
Has this person won a Hugo Award for Best Novel?
Recorded Guesser outputRequired JSON format
{"result":{"action":"ASK","description":null,"name":null,"question":"Has this person won a Hugo Award for Best Novel?"}}Oracle evidence2 model-reported sources
The Oracle reported these excerpts and URLs. They are not independently checked.
1988: Misery (Viking) novel — nomination.Open sfadb.com (opens in a new tab)
Novel — Winner: The Uplift War, David Brin.Open sfadb.com (opens in a new tab)
Has this person won a Nebula Award for Best Novel?
Recorded Guesser outputRequired JSON format
{"result":{"action":"ASK","description":null,"name":null,"question":"Has this person won a Nebula Award for Best Novel?"}}Oracle evidence2 model-reported sources
The Oracle reported these excerpts and URLs. They are not independently checked.
Nebula Awards — for SF/F works ... (1 nomination)Open sfadb.com (opens in a new tab)
Novel — Winner: Timescape, Gregory BenfordOpen sfadb.com (opens in a new tab)
Has this person published more than ten novels?
Recorded Guesser outputRequired JSON format
{"result":{"action":"ASK","description":null,"name":null,"question":"Has this person published more than ten novels?"}}Oracle evidence1 model-reported source
The Oracle reported these excerpts and URLs. They are not independently checked.
Stephen King has published 64 novels.Open wordsrated.com (opens in a new tab)
Is this person known for writing a long-running series of urban fantasy detective novels?
Recorded Guesser outputRequired JSON format
{"result":{"action":"ASK","description":null,"name":null,"question":"Is this person known for writing a long-running series of urban fantasy detective novels?"}}Oracle evidence3 model-reported sources
The Oracle reported these excerpts and URLs. They are not independently checked.
Stephen King is an American novelist and short-story writer whose books are credited with reviving the genre of horror fiction.Open britannica.com (opens in a new tab)
Mercedes, Finders Keepers, and End of Watch form a trilogy of hard-boiled crime novels centering on retired detective Bill Hodges.Open britannica.com (opens in a new tab)
The Dresden Files are Jim’s first published series, telling the story of Harry ... Dresden, Chicago’s first ... Wizard P.I.Open jim-butcher.com (opens in a new tab)
Has an HBO television series been adapted from this person's novels?
Recorded Guesser outputRequired JSON format
{"result":{"action":"ASK","description":null,"name":null,"question":"Has an HBO television series been adapted from this person's novels?"}}Oracle evidence2 model-reported sources
The Oracle reported these excerpts and URLs. They are not independently checked.
About This Series Based on Stephen King’s novel, this psychological thriller follows the grim murder of a boy and the mysterious forces surrounding the case.Open hbomax.com (opens in a new tab)
The Outsider Review: Stephen King's Novel Gets A Serious HBO Adaptation.Open npr.org (opens in a new tab)
George R. R. Martin
American novelist best known for the A Song of Ice and Fire fantasy series adapted into HBO's Game of Thrones.
Validator rationale The trusted subject is Stephen King, while the proposed identity is George R. R. Martin, a different author.
Recorded Guesser outputRequired JSON format
{"result":{"action":"GUESS","description":"American novelist best known for the A Song of Ice and Fire fantasy series adapted into HBO's Game of Thrones.","name":"George R. R. Martin","question":null}}Is this person primarily associated with horror fiction?
Recorded Guesser outputRequired JSON format
{"result":{"action":"ASK","description":null,"name":null,"question":"Is this person primarily associated with horror fiction?"}}Oracle evidence2 model-reported sources
The Oracle reported these excerpts and URLs. They are not independently checked.
He is best known for his works in the horror and fantasy genres.Open cnn.com (opens in a new tab)
Stephen (Edwin) King ... U.S. writer of horror stories.Open britannica.com (opens in a new tab)
Stephen King
Living American male horror novelist with many novels, including works adapted as HBO's The Outsider.
Validator rationale The proposed identity matches Stephen King, the American horror novelist; the description and works are consistent with the trusted subject.
Recorded Guesser outputRequired JSON format
{"result":{"action":"GUESS","description":"Living American male horror novelist with many novels, including works adapted as HBO's The Outsider.","name":"Stephen King","question":null}}