3D Chess.

3D Chess is a complete chess game on a rendered board with black and white squares, a gold grid and a–h, 1–8 labels. The pieces are built in code from turned profiles and simple shapes, lit with physically based materials and soft shadows.

The rules are all there: castling, en passant, promotion with a piece picker, check, checkmate, stalemate, and draws by threefold repetition, the fifty-move rule or insufficient material. Moves are logged in standard algebraic notation, and you can undo them. Click one of your pieces and it lifts and lights up, with a dot on every square it can legally move to, red on squares where it can capture. The last move and any check are highlighted too.

The AI is on by default and plays Black against you. It uses an alpha-beta search with a capture search at the end, up to five plies (half-moves) deep, thinking for at most a second and a half on a desktop. We haven’t measured its strength. Turn it off to play two people on one screen. When a piece is captured it is not simply removed: it lifts off the board, drifts through the air trailing sparkles and lowers itself, upright, onto a felt tray at the side. Sounds are synthesised on the fly.