(2) That no Pieces or Pawns intervene.
(3) That the King is not in check.
(4) That the King does not have to cross and does not move to a square commanded by an opposing Piece or Pawn.
Center. Pawns in the middle field, especially if well supported. It is usually a great object to keep the center intact, or unbroken and to break the center of the adversary if it be stronger.
Check. The warning which must be given when the adversary's King is attacked. In such a case, the King is said to be "in check" and the threatened capture must be avoided by:
(1) Taking the attacking Piece or Pawn.
(2) Moving the King.
(3) Interposing or moving another Piece or Pawn between the King and the attacking Piece or Pawn.
For example, if the White King stands on QR4 and the Black Queen's Rook stands on QE8, then the White King is
