About and credits

Chess on myGames.cards. Play against the computer at eight strength levels; online games against other players are coming next.

Computer opponent: Stockfish

The computer player is Stockfish, a free and open-source chess engine by the Stockfish developers, in the WebAssembly build Stockfish.js by Nathan Rugg and Chess.com (version 18, “lite single-threaded”). It runs in your own browser.

Stockfish is licensed under the GNU General Public License, version 3 (GPL-3). This site uses it unmodified, as a separate program: the files engine/stockfish-18-lite-single.js and engine/stockfish-18-lite-single.wasm. The complete source code is available at github.com/nmrugg/stockfish.js (this build: npm package stockfish version 18.0.8) and github.com/official-stockfish/Stockfish. You may copy, change and share Stockfish under the terms of that licence.

Chess rules: chess.js

Legal moves, check, checkmate and draws are worked out by chess.js (version 1.4.0) by Jeff Hlywa, used under the BSD 2-Clause licence.

Everything else

The rest of the site (pages, board, game and lobby code, artwork) is by myGames.cards. See the Terms of Use at the bottom of the lobby.