Chess Offline - Play vs AI

A complete chess game that runs entirely on your phone. You play against the built-in engine — no internet connection, no account, no ads, no in-app purchases, and nothing collected about you.

Please note: the interface is currently in Vietnamese. Moves are shown in standard algebraic notation (e4, Nf3, O-O, Qxh7#), which reads the same in any language.

A NATIVE C++ ENGINE
The chess rules and the search are written in C++ and ship as a native library. The engine thinks on a background thread, so the board stays smooth while it calculates. On the Win At Chess suite — a 300-position tactical test that chess programmers have used as a standard benchmark for decades — it solves 285 of the 300 positions at 3 seconds per position, measured on a development machine. The hardest level is designed to target roughly 2400 Elo; that is the design goal we built toward, not a rating confirmed in tournament play.

THREE LEVELS, THREE DIFFERENT OPPONENTS
The levels differ in search depth, evaluation and thinking time — not just in how far ahead they look.

Easy — aimed at about 900 to 1100 Elo. It develops its pieces, castles, and takes material you leave hanging. It also overlooks things, the way a beginner does. It never plays random moves, so games still feel like chess.

Medium — aimed at about 1600 to 1800 Elo. A club-level opponent that finds three- and four-move combinations, uses pins and forks, and goes after a king that has not castled. You have to concentrate to beat it.

Hard — no deliberate mistakes. Full opening book, and it keeps calculating during your turn, so its reply is often ready the moment you move.

THE COMPLETE FIDE RULES
Castling with all its restrictions, en passant, promotion to queen, rook, bishop or knight, the fifty-move rule, threefold repetition, insufficient material, and stalemate scored as a draw. Every legality question is answered by the engine itself, so the rules are exactly the ones used over the board.

ON THE BOARD
- Three board themes: Wood, Marble, Classic Green
- Tap a piece then tap a square, or drag and drop — both work, no setting to change
- Legal-move dots, capture rings, last-move highlight, and a clear check indicator
- Take back a move, as often as you like
- Hints, three per game, drawn as an arrow on the board
- Flip the board at any time
- A scrollable move list in algebraic notation — tap any move to replay the position
- Captured-piece tray showing the material difference
- Optional evaluation bar, off by default, and it never updates while it is your turn
- Sound effects and haptic feedback, both switchable
- Automatic save: close the app in the middle of a game and pick it up later
- Finished games are written out as PGN files you can open or share
- Win, loss and draw statistics per level, plus an estimated rating for you
- Settings for animation speed, coordinates, move hints, and auto-queen promotion

PRIVACY, IN PLAIN TERMS
The app requests exactly one Android permission: vibrate, for haptic feedback. It does not request internet access at all, which means it cannot send anything anywhere even if it wanted to. There is no analytics, no advertising SDK, no third-party library phoning home, and no sign-in of any kind.

Your saved game, settings, statistics and estimated rating live in the app's private storage on your device. Nothing is uploaded, and everything is removed when you uninstall the app.

CREDITS
The chess pieces are original vector artwork drawn specifically for this app, in the public-domain Staunton style. Built with the Godot Engine (MIT licence). Sound effects were generated with our own scripts.

WHAT THIS APP IS NOT
There is no online play, no puzzles or lessons, no tournament clock and no cloud analysis. It is one thing done properly: a strong offline opponent, correct rules, and a board that is pleasant to look at.