Ulam's game

Ulam's game, or the Rényi–Ulam game, is a mathematical game similar to the popular game of twenty questions. In Ulam's game, a player attempts to guess an unnamed object or number by asking yes–no questions of another, but one of the answers given may be a lie.[1]

Alfréd Rényi (1961) introduced the game in a 1961 paper, based on Hungary's Bar Kokhba game, but the paper was overlooked for many years.

Stanislaw Ulam (1976,p. 281) rediscovered the game, presenting the idea that there are a million objects and the answer to one question can be wrong, and considered the minimum number of questions required, and the strategy that should be adopted.[2] Pelc (2002) gave a survey of similar games and their relation to information theory.

See also


  1. "How to Play Ulam's Game" (PDF). Retrieved 13 June 2013.
  2. Beluhov, Nikolai (2016). "Renyi-Ulam Games and Forbidden Substrings". arXiv:1609.07367 [math.CO].