Quellstone: 3D Chess

Quellstone is a chess game with a three-dimensional board, made to be played with your phone upright. The games take place in a town square with stone chess tables.

You play against eight regulars of the square, from Tiaguinho, the kid who plays fast, to Seu Osvaldo, the master of the square. Each one has a face, a style and their own lines: they greet you when they sit down, react to your checks and comment on the end of the game. On your first game, Quellstone asks whether you already play chess and suggests an opponent. You can also play against another person on the same device, with the board turning toward whoever moves next.

Checkmate puzzles
• 400 puzzles from real games in the open Lichess database: 150 mates in 1 and 250 mates in 2, in order of difficulty.
• A daily puzzle, the same for everyone on the same date, with a count of days in a row.

The chess engine and every rule were written for this game: castling, en passant, promotion, stalemate, threefold repetition and the fifty-move rule. The clock is optional and follows the FIDE Laws of Chess, including the draw when a flag falls and the opponent has no material to give checkmate.

During and after the game
• Hint: the first tap shows the piece of the best move, the second shows the square.
• A refused move tells you why.
• Analysis of the finished game, with a classification for every move and the best move when there was a mistake.
• A personal rating that goes up when you win and down when you lose.
• Moves written in a notebook, the game as PGN, and statistics by color and by opening.

Your way
• Tap and tap, or drag and drop.
• Move confirmation and undo.
• Five board colors, high contrast and a left-handed layout.
• 13 languages: English, Portuguese, Spanish, German, French, Italian, Russian, Polish, Turkish, Indonesian, Japanese, Korean and Traditional Chinese.

Plays without internet, with no ads and no sign-up. The game only talks to Google Play, to check and make purchases. The chess game is complete and free. The shop has Living Pieces mode, where the pieces become characters that run and fight, with three free games before the one-time purchase, and tips for anyone who wants to support the game. Your games stay on your device.