Chess vs Computer

How to play Chess against the computer

This is single-player chess against a computer opponent that runs right in your browser. Pick a side and one of three difficulty levels — Easy, Normal or Expert — then try to checkmate the computer. Every win earns ranking points on the leaderboard (+10, +30 or +100), and all the standard rules apply, including castling, en passant and promotion.

Starting a game against the computer

• Choose White or Black. White always moves first, so if you take Black the computer makes the opening move.
• Choose a difficulty: Easy, Normal or Expert. Each button shows how many ranking points a win on that level is worth.
• Press Start game. The board appears and whichever side moves first begins.

Controls

• On your turn, tap/click one of your pieces to see its legal moves, then tap/click a highlighted target to move there. Tap another of your pieces to change the selection.
• The computer answers automatically after a short pause — the status line shows “Computer is thinking…” while it chooses its move.
• There is no undo: once a move is made it stands, just like a real ranked game.
• New game returns to the setup screen so you can change side or level. An unfinished game scores nothing.

Difficulty levels and ranking points

• Easy (+10 per win) — the computer looks only one move ahead and about half the time plays a deliberately weaker move. Ideal for learning the rules.
• Normal (+30 per win) — it looks two moves ahead (its move and your best reply) and only occasionally slips, about one move in ten.
• Expert (+100 per win) — it searches three moves deep (its move, your reply, its follow-up) and never blunders on purpose. Leave a piece unprotected and it will take it.

Only a win scores. A loss or a draw earns nothing, so just start again. Your best result on each level is shown on the leaderboard: wins are saved on this device and uploaded automatically when you are signed in and online.

How the pieces move

• Pawn — forward one square (or two from its starting row), captures diagonally.
• Knight — an L-shape; the only piece that jumps over others.
• Bishop — any distance diagonally.
• Rook — any distance horizontally or vertically.
• Queen — any distance in any straight line.
• King — one square in any direction.

Special moves (all supported)

• Castling — if neither the king nor the chosen rook has moved, the squares between them are empty, and the king is not moving into, out of, or through check, tap the king two squares toward the rook to castle.
• En passant — if an enemy pawn jumps two squares and lands beside yours, you may capture it as if it had moved only one, but only on the very next move.
• Promotion — a pawn that reaches the far rank is automatically promoted to a queen (auto-queen).

Winning, check and draws

When your king is attacked you are in check and must get out of it — the game tells you. If a player to move has no legal move and their king is in check, that is checkmate and the other player wins. If they have no legal move but are not in check, it is stalemate — a draw. The engine only ever offers legal moves, so you can’t accidentally leave your own king in check.

Frequently asked questions