Two-player Domino games
Benjamin Hellouin de Menibus, Rémi Pallen
TL;DR
This work studies a two-player Domino game on the infinite grid $\mathbb{Z}^d$, where $A$ aims to realize a pattern from a finite target set $\mathcal{F}$ and $B$ seeks to prevent it. It shows the Domino game problem on $\mathbb{Z}^d$ for $d>1$ is $\Sigma^0_1$-complete (hence undecidable) by a reduction from the classical Domino problem and proves that if $A$ wins, the win occurs in bounded time. A bounded-time variant is shown decidable, and a non-alternating variant with turn-order words $s$ (balanced) is characterized: the set of $s$ with $A$-winning is a subshift and the decision problem is decidable in many cases depending on the frequency $f_A(s)$, with a complete partition of several regimes. The paper connects symbolic dynamics and computability to game-theoretic tiling, providing insights into why determining winners in infinite-grid games is intricate, and it poses several open questions about the complexity of strategies and pass-less variants.
Abstract
We introduce a 2-player game played on an infinite grid, initially empty, where each player in turn chooses a vertex and colours it. The first player aims to create some pattern from a target set, while the second player aims to prevent it. We study the problem of deciding which player wins, and prove that it is undecidable. We also consider a variant where the turn order is not alternating but given by a balanced word, and we characterise the decidable and undecidable cases.
