When your pawn reaches the last rank (rank 8 for white, rank 1 for black), it must be promoted. Choose any piece: Queen ♛, Rook, Bishop, or Knight. Queen is almost always the best choice.

The king moves 2 squares toward a rook, and the rook jumps to the other side. Allowed only when: neither piece has moved, no pieces between them, the king is not in check, and doesn't pass through or land on an attacked square. Kingside (short) or queenside (long).

If an opponent's pawn advances 2 squares and lands beside your pawn, you may capture it as if it had only moved 1 square — your pawn moves diagonally to the square behind the captured pawn. This special capture is only available immediately on the very next move.

When your king is directly attacked by an opponent's piece, you are in check. You must escape check immediately — by moving the king, blocking the attack, or capturing the attacker. You cannot make a move that leaves your king in check.

When the king is in check and there is no legal move to escape, it's checkmate. The player in checkmate loses. This is the ultimate goal of chess.

If the player to move has no legal moves but is not in check, it's stalemate — the game is a draw. This is a common trap that losing players try to force.

If the same position (same pieces, same rights to castle/en passant, same side to move) occurs 3 times during a game, either player can claim a draw. Commonly happens in endgames where both sides repeat moves.

If 50 consecutive moves are made by both players without a pawn move or a capture, either player can claim a draw. This prevents games from going on forever in positions where neither side can win.

The game is automatically drawn when neither side has enough pieces to deliver checkmate. Examples: King vs King, King + Bishop vs King, King + Knight vs King.