English

Infinite Wordle and the Mastermind numbers

Logic 2023-09-06 v3 Computer Science and Game Theory

Abstract

I consider the natural infinitary variations of the games Wordle and Mastermind, as well as their game-theoretic variations Absurdle and Madstermind, considering these games with infinitely long words and infinite color sequences and allowing transfinite game play. For each game, a secret codeword is hidden, which the codebreaker attempts to discover by making a series of guesses and receiving feedback as to their accuracy. In Wordle with words of any size from a finite alphabet of nn letters, including infinite words or even uncountable words, the codebreaker can nevertheless always win in nn steps. Meanwhile, the mastermind number, defined as the smallest winning set of guesses in infinite Mastermind for sequences of length ω\omega over a countable set of colors without duplication, is uncountable, but the exact value turns out to be independent of ZFC, for it is provably equal to the eventually different number d()\frak{d}({\neq^*}), which is the same as the covering number of the meager ideal cov(M)\text{cov}(\mathcal{M}). I thus place all the various mastermind numbers, defined for the natural variations of the game, into the hierarchy of cardinal characteristics of the continuum.

Keywords

Cite

@article{arxiv.2203.06804,
  title  = {Infinite Wordle and the Mastermind numbers},
  author = {Joel David Hamkins},
  journal= {arXiv preprint arXiv:2203.06804},
  year   = {2023}
}

Comments

22 pages, 5 figures. Comments can be made at http://jdh.hamkins.org/infinite-wordle-mastermind. v2 has minor updates and corrections. v3 makes a minor correction to theorem 11 statement 2 and a few other minor ambiguities

R2 v1 2026-06-24T10:11:46.763Z