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  "path": "/abs/2605.22747v1",
  "publishedAt": "2026-05-22T00:00:00.000Z",
  "site": "https://arxiv.org",
  "tags": [
    "Marius Drop",
    "Benjamin G. Rin",
    "Finn van der Velde"
  ],
  "textContent": "**Authors:** Marius Drop, Benjamin G. Rin, Finn van der Velde\n\nQuoridor is an award-winning abstract strategy game designed by Mirko Marchesi and published in 1997. Similar games include Maze Attack, Blockade (also known as Cul-de-sac), and Pinko Pallino. In line with chess, checkers, Go, and other classic combinatorial games, Quoridor is a turn-based, deterministic, perfect-information game played on a square grid. We show that it is PSPACE-complete to determine whether a given player has a winning strategy in a given Quoridor position on a board with size $n \\times n$. We prove this by reduction from Gpos(POS CNF), a Boolean formula game originally defined in 1978 by T. Schaefer.",
  "title": "Quoridor is PSPACE-Hard"
}