ChessCraft

From the Devs

Never play the same game of chess again! ChessCraft is a chess AI sandbox. Create your own chess boards, rules, and pieces. Play against the computer or your friends online, or win loot by playing one of 80 built-in chess boards in adventure mode. ChessCraft is also the world's largest chess variant database.

Many chess games already exist, but only ChessCraft allows the player to create such wacky boards, pieces, and rules and immediately play a decent computer opponent.

Create new pieces with any combination of the 8 bishop or rook slides, plus a 7x7 grid of knight-like hops. Create new boards with any enabled or disabled tile up to 16x16. Place promotion rules for any piece, anywhere, or other special tile rules. Create pieces that cannot be captured, or with ranged attacks, or pieces that restrict other pieces from acting. The computer opponent then uses concepts from computer science and graph theory to understand your creations and play against you.