Play Chess vs Computer
Play a full game of chess against the computer, from a gentle beginner level to a tough Stockfish opponent. Drag or click your pieces; every rule is enforced for you.
Promote to
Your move
Engine: built-in
Moves will appear here.
How to use the Play Chess vs Computer
- Choose your colour and level. Pick White, Black or Random and a computer level from 1 (beginner) to 8 (maximum).
- Make a move by clicking a piece and then a highlighted square, or by dragging the piece. Dots show quiet moves and rings show captures.
- Wait for the reply. The computer answers in under a few seconds; the last move is highlighted on the board.
- Use Undo move or Flip board whenever you like. Undo takes back your move and the computer's reply.
- Save the game with Copy PGN or Download PGN, or paste a FEN and press Load FEN to practise any position.
Chess piece values and how the computer counts material
| Piece | SAN letter | Usual value | Moves |
|---|---|---|---|
| Pawn | (none) | 1 | One square forward (two from its starting square), captures diagonally |
| Knight | N | 3 | An L-shape: two squares one way and one square sideways; can jump over pieces |
| Bishop | B | 3 | Any distance diagonally |
| Rook | R | 5 | Any distance along a rank or file |
| Queen | Q | 9 | Any distance in a straight line or diagonally |
| King | K | – | One square in any direction; castles with a rook |
The +N next to the captured pieces uses these classic values, so +3 means you are roughly a minor piece ahead. The built-in engine uses finer values in centipawns (pawn 100, knight 320, bishop 330, rook 500, queen 900), adds a bonus for the bishop pair, and scores where each piece stands with piece-square tables, so a knight in the centre is worth more than one on the rim.
Reading the move list (SAN)
Moves are written in Standard Algebraic Notation, the same format used in books, PGN files and tournament score sheets:
- Nf3: a knight moves to f3. Pawn moves show only the square, for example e4.
- Bxe5: a bishop captures on e5. A pawn capture starts with the file it came from, as in exd5.
- Nbd2 or R1e2: when two identical pieces can reach the same square, the file or rank of the moving piece is added.
- O-O and O-O-O: castling kingside and queenside.
- e8=Q: pawn promotion. + marks check and # marks checkmate.
Five habits that win more games against the computer
- Develop first. Bring out knights and bishops, castle early and connect your rooks before starting an attack.
- Check every capture and check. Before each move, look at all checks, captures and threats for both sides. The computer never overlooks a hanging piece.
- Trade when ahead. If you win material, exchange pieces (not pawns) to reach a simple winning endgame.
- Use undo to learn. When you lose material, take the move back and find what you missed instead of just replaying.
- Climb the levels. Move up a level once you win most games at your current one; each level searches deeper or makes fewer deliberate mistakes.
Special rules in brief
Castling is allowed only if neither the king nor that rook has moved, the squares between them are empty, and the king is not in check, does not pass through an attacked square and does not land in check. En passant: a pawn that advances two squares can be captured by an enemy pawn standing beside it, as if it had moved only one square, but only on the very next move. A position counts as repeated when the same pieces stand on the same squares with the same side to move and the same castling and en passant rights.
Frequently asked questions
Which chess engine does the computer use?
When you are online, the tool loads Stockfish 10, a free open-source engine, and limits its skill level, depth and thinking time according to the level you choose. If Stockfish can't load (for example offline or on a blocked network), a built-in JavaScript engine takes over automatically, using alpha-beta search, quiescence search and piece-square tables.
Which level should I choose?
Levels 1 and 2 make frequent mistakes and suit beginners and children. Levels 3 and 4 play like a casual club player. Levels 5 and 6 are challenging for most club players, and levels 7 and 8 are very strong, especially when Stockfish is active.
How do I castle, capture en passant or promote a pawn?
To castle, move your king two squares toward the rook and the rook jumps over automatically. En passant appears as a normal highlighted capture when it is allowed. When a pawn reaches the last rank, a menu lets you choose a queen, rook, bishop or knight.
Why did the game end in a draw?
The game is drawn automatically by stalemate (the side to move has no legal moves but is not in check), threefold repetition of the same position, the 50-move rule (50 moves by each side with no capture or pawn move), or insufficient material such as king and bishop against king.
What are PGN and FEN?
PGN (Portable Game Notation) records the moves of a whole game and can be opened in any chess program or website for analysis. FEN (Forsyth-Edwards Notation) describes a single position in one line, including whose turn it is, castling rights and the en passant square.
Can I set up my own position?
Yes. Paste a FEN string into the Position (FEN) box and press Load FEN. The game continues from that position with you playing the colour selected under Play as; if it is the computer's turn, it moves first.
Is my game saved or sent anywhere?
No. The game runs entirely in your browser. Only your settings (colour, level and engine) are remembered on this device. Copy or download the PGN if you want to keep a game.