Optimal play in 'Guess Who?'

• Published in 2025
• Added on 2026-01-28

We prove an optimal strategy for the children's game Guess Who? assuming the official rules are in use and that both players ask `classical' questions with a bipartite response. Applying a technique described in [Rabern, B \& Rabern, L 2008, 'A simple solution to the hardest logic puzzle ever', \textit{Analysis}, vol. 68, no. 2, pp.~105-112.] allows for questions with tripartite responses; we explain this innovation and give an optimal strategy for two players applying it.

Links

• https://arxiv.org/abs/2508.00799v3
• https://arxiv.org/pdf/2508.00799v3

Other information

BibTeX entry

@article{OptimalplayinGuessWho,
	key = {OptimalplayinGuessWho},
	type = {article},
	title = {Optimal play in 'Guess Who?'},
	author = {David Cushing and Stuart Gipp and Ezra Levick and Em Rickinson and David I. Stewart},
	abstract = {We prove an optimal strategy for the children's game Guess Who? assuming the official rules are in use and that both players ask `classical' questions with a bipartite response. Applying a technique described in [Rabern, B \{\&} Rabern, L 2008, 'A simple solution to the hardest logic puzzle ever', \textit{\{}Analysis{\}}, vol. 68, no. 2, pp.{\~{}}105-112.] allows for questions with tripartite responses; we explain this innovation and give an optimal strategy for two players applying it.},
	comment = {},
	date_added = {2026-01-28},
	date_published = {2025-01-28},
	urls = {https://arxiv.org/abs/2508.00799v3,https://arxiv.org/pdf/2508.00799v3},
	collections = {games-to-play-with-friends,protocols-and-strategies},
	url = {https://arxiv.org/abs/2508.00799v3 https://arxiv.org/pdf/2508.00799v3},
	year = 2025,
	urldate = {2026-01-28},
	archivePrefix = {arXiv},
	eprint = {2508.00799},
	primaryClass = {math.CO}
}