Chess

How to play

Standard chess rules: pawns, knights, bishops, rooks, the queen, and the king, each moving the way you already know. Tap a piece to select it — its legal destinations are marked on the board — then tap one to move there. You are White and move first. Checkmate the opposing king to win; if the side to move has no legal move and isn't in check, the game is a stalemate and ends in a draw.

Castling, en passant, and pawn promotion are all supported. When a pawn reaches the far rank, you'll be asked which piece to promote it to — almost always a queen, but the choice is yours.

Playing the computer, or a friend

The computer opponent is Stockfish, one of the strongest chess engines in the world, running entirely in your browser — nothing about your game is sent anywhere. Easy plays a noticeably weaker, more human game with real mistakes in it. Medium is a solid club-level opponent. Hard plays close to Stockfish's full strength for a single-threaded browser build, and beating it is a genuine achievement.

Switching the opponent to two players passes the same board back and forth on one device, with no computer involved. Your game is saved in this browser as you play, so closing the tab does not cost you the position.

Tips for a stronger game

Develop your knights and bishops before you move the same piece twice, and get your king safely castled early. A slow start spent shuffling one piece back and forth is the most common way an otherwise sound player falls behind in the opening.

Look for checks, captures, and threats before anything quieter — in that order, on every move, for both sides. Most tactical mistakes come from missing something forcing that was available, not from failing to find a brilliant quiet move.

Trade pieces when you're ahead in material, and avoid trades when you're behind. Fewer pieces on the board make a material advantage count for more, which is exactly why the side who's behind should be looking to keep the position complicated instead.