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
- 13
- Outcome
- Solved
- Format errors
- Errors found View one example
- Duration
- 7m 59s
- Round cost
- $0.1448 All 14 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
- 92.9%
- 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":"EAQCORIU"}Valid replies are shown in the required format. Rejected replies are shown separately, without provider or call IDs.
Reply in the wrong format.
Invalid action · fixed format reminder sent
Why this reply was rejectedInvalid action · turn 1
The reply was JSON, but it matched neither the ASK nor the GUESS format.
- Recorded type
invalid_action- Turn
- 1
- Counted
- Yes · question 1
- Feedback
- FORMAT_ERROR
{"action":"ASK","question":"Is this person still alive?"}{"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 a fictional character rather than a real human being?
Recorded Guesser outputRequired JSON format
{"result":{"action":"ASK","description":null,"name":null,"question":"Is this person a fictional character rather than a real human being?"}}Oracle evidence1 model-reported source
The Oracle reported these excerpts and URLs. They are not independently checked.
Stephen Edwin King (born September 21, 1947) is an American author.Open en.wikipedia.org (opens in a new tab)
Is this person still alive?
Recorded Guesser outputRequired JSON format
{"result":{"action":"ASK","description":null,"name":null,"question":"Is this person still alive?"}}Oracle evidence2 model-reported sources
The Oracle reported these excerpts and URLs. They are not independently checked.
Stephen King’s official website announces his upcoming novel, *Other Worlds Than These*, coming October 6th, 2026, and identifies him as its author.Open stephenking.com (opens in a new tab)
Stephen King’s official website lists news covering 2026, 2025, and 2024, including an interview with Stephen.Open stephenking.com (opens in a new tab)
Is this person primarily known for politics or government leadership?
Recorded Guesser outputRequired JSON format
{"result":{"action":"ASK","description":null,"name":null,"question":"Is this person primarily known for politics or government leadership?"}}Oracle evidence2 model-reported sources
The Oracle reported these excerpts and URLs. They are not independently checked.
Stephen Edwin King is an American author, widely known for his horror fiction.Open en.wikipedia.org (opens in a new tab)
Best Known For: Stephen King is a 'New York Times'-bestselling novelist who made his name in the horror and fantasy genres.Open biography.com (opens in a new tab)
Is this person primarily known as a performer or entertainer (actor, musician, singer)?
Recorded Guesser outputRequired JSON format
{"result":{"action":"ASK","description":null,"name":null,"question":"Is this person primarily known as a performer or entertainer (actor, musician, singer)?"}}Oracle evidence1 model-reported source
The Oracle reported these excerpts and URLs. They are not independently checked.
Stephen King is a 'New York Times'-bestselling novelist who made his name in the horror and fantasy genres with books like 'Carrie,' 'The Shining' and 'IT.'Open biography.com (opens in a new tab)
Is this person primarily known as an athlete?
Recorded Guesser outputRequired JSON format
{"result":{"action":"ASK","description":null,"name":null,"question":"Is this person primarily known as an athlete?"}}Oracle evidence1 model-reported source
The Oracle reported these excerpts and URLs. They are not independently checked.
Best Known For: Stephen King is a 'New York Times'-bestselling novelist who made his name in the horror and fantasy genres.Open biography.com (opens in a new tab)
Is this person known primarily for work in science or technology?
Recorded Guesser outputRequired JSON format
{"result":{"action":"ASK","description":null,"name":null,"question":"Is this person known primarily for work in science or technology?"}}Oracle evidence2 model-reported sources
The Oracle reported these excerpts and URLs. They are not independently checked.
Stephen King is a 'New York Times'-bestselling novelist who made his name in the horror and fantasy genres.Open biography.com (opens in a new tab)
Stephen King is a prolific American novelist known for blending horror, fantasy, science fiction, and the macabre.Open britannica.com (opens in a new tab)
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.
Gender: MaleOpen biography.com (opens in a new tab)
Is this person primarily known for business, such as founding or leading a major company?
Recorded Guesser outputRequired JSON format
{"result":{"action":"ASK","description":null,"name":null,"question":"Is this person primarily known for business, such as founding or leading a major company?"}}Oracle evidence2 model-reported sources
The Oracle reported these excerpts and URLs. They are not independently checked.
Best Known For: Stephen King is a 'New York Times'-bestselling novelist who made his name in the horror and fantasy genres.Open biography.com (opens in a new tab)
American novelist.Open britannica.com (opens in a new tab)
Is this person primarily known as a writer or author?
Recorded Guesser outputRequired JSON format
{"result":{"action":"ASK","description":null,"name":null,"question":"Is this person primarily known as a writer or author?"}}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.Open britannica.com (opens in a new tab)
Best-selling author Stephen King rose to fame in the 1970s with his debut novel Carrie.Open biography.com (opens in a new tab)
Is this person from the United States?
Recorded Guesser outputRequired JSON format
{"result":{"action":"ASK","description":null,"name":null,"question":"Is this person from the United States?"}}Oracle evidence1 model-reported source
The Oracle reported these excerpts and URLs. They are not independently checked.
Stephen King was born in Portland, Maine in 1947.Open stephenking.com (opens in a new tab)
Is this person best known for writing novels?
Recorded Guesser outputRequired JSON format
{"result":{"action":"ASK","description":null,"name":null,"question":"Is this person best known for writing novels?"}}Oracle evidence1 model-reported source
The Oracle reported these excerpts and URLs. They are not independently checked.
Stephen King is a 'New York Times'-bestselling novelist who made his name in the horror and fantasy genres.Open biography.com (opens in a new tab)
Is this person best known for writing horror fiction?
Recorded Guesser outputRequired JSON format
{"result":{"action":"ASK","description":null,"name":null,"question":"Is this person best known for writing horror fiction?"}}Oracle evidence2 model-reported sources
The Oracle reported these excerpts and URLs. They are not independently checked.
Dubbed the “King of Horror,” he is widely known for his horror fiction.Open en.wikipedia.org (opens in a new tab)
Stephen King ... has since become known as the “King of Horror.”Open biography.com (opens in a new tab)
Stephen King
American author best known for writing horror novels such as Carrie, The Shining, and It
Validator rationale The proposed identity matches Stephen King, the American author associated with Carrie, The Shining, and It.
Recorded Guesser outputRequired JSON format
{"result":{"action":"GUESS","description":"American author best known for writing horror novels such as Carrie, The Shining, and It","name":"Stephen King","question":null}}