QUIXO is EXPTIME-complete
Shohei Mishiba, Yasuhiko Takenaga · Information Processing Letters · 2020
QUIXO is a two-player strategic board game played on a 5×5 game board. Players alternately move cubes on the game board, and the player who first made a line of five cubes with the player's symbol wins the game. In this paper, we prove EXPTIME-completeness of deciding the winner on generalized QUIXO played on an n×n game board.