The ladder. The engine has 30 rungs of strength. Beat it and it climbs one rung for your next game. Lose and it drops one. A draw leaves it where it is. Your rung is saved to your name, so every player at the table has their own.

Moving. Tap a piece, then a square, or drag it. Legal squares are marked. Pawns reaching the last rank ask what to promote to.

Potential moves. The ⚡ button lights up the squares pieces could move to right now: just the piece you've selected, all of your pieces (blue), all of your opponent's (red), or both at once (purple where they overlap). The same setting applies in the openings book.

Hints. A hint shows the engine's favourite move for you. Hinted games are flagged, and you can choose whether they count on the ladder.

Undo takes back your last move (the engine's reply too). Draw offers are accepted when the engine thinks the position is level. Resign ends the game as a loss.

Offline. Everything runs on your device: the engine, your games and your stats. Install it from the home screen and play without a signal.

bChess is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License, version 3 or (at your option) any later version. It is distributed in the hope that it will be useful, but without any warranty; without even the implied warranty of merchantability or fitness for a particular purpose. See the licence. The complete source code is in the buildfun repository.

Engine: Stockfish, copyright © T. Romstad, M. Costalba, J. Kiiski, G. Linscott and other contributors; compiled to WebAssembly as stockfish.js 10.0.2 by Niklas Fiekas (GPL-3.0).

Rules: chess.js 1.4.0, copyright © Jeff Hlywa (BSD-2-Clause).

Pieces: Classic by Colin M.L. Burnett (GPLv2+), Merida by Armando Hernandez Marroquin (GPLv2+), Fantasy by Maurizio Monge (MIT), Chessnut by Alexis Luengas (Apache 2.0), Rhos by RhosGFX (CC0), Kiwen-suwi by neverRare (CC BY 4.0), all via the lichess collection.

Openings: names and lines from lichess-org/chess-openings (CC0).