The object of the game is to checkmate the opponent's king, whereby
the king is under immediate attack (in "check") and there is no way to
remove it from attack on the next move.
Basic rules of the game:
1. The white player always moves first.
2. Pieces are moved to either an unoccupied square, or one
occupied by an opponent's piece, capturing it and removing it from play.
3. When a king is under immediate attack by one or two of the
opponent's pieces, it is said to be in check. The only permitted
responses to a check are to capture the checking piece, interpose a
piece between the checking piece and the king (unless the attacking
piece is a knight), or move the king to a square where it is not under
4. Each chess piece has its own unique style of movement