Chess is a strategic two-player board game played on an 8×8 board, with each side starting with sixteen pieces: one king, one queen, two rooks, two bishops, two knights, and eight pawns. The objective is to checkmate the opponent's king, meaning the king is in check and has no legal escape from capture. When a player has no legal moves but is not currently in check, the position is a stalemate and results in a draw.
Each piece moves in its own distinctive way. Pawns move forward one square, or two squares on their first move, and capture diagonally. Knights leap in an L-shape, two squares in one direction and one perpendicular, allowing them to jump over other pieces. Bishops travel diagonally any number of squares, rooks move horizontally or vertically any number of squares, and the queen combines the powers of rook and bishop, moving any direction any distance. The king moves one square in any direction.
Several special moves give chess its richness. Castling allows the king to move two squares toward a rook while the rook jumps to the king's other side, provided neither piece has moved, the squares between them are empty, the king is not in check, and the king does not pass through or land on an attacked square. En passant permits a pawn to capture an enemy pawn that has just advanced two squares past it, but only on the immediately following move. Promotion transforms a pawn into a queen, rook, bishop, or knight when it reaches the last rank. A recurring development idea is the fianchetto, where a bishop is developed to b2 or g2 (or the corresponding seventh-rank squares) to exert influence along the long diagonal.