A player is said to have the opposition when he can place his King directly in front of the adverse King, with only one square between them. This is often an important advantage in ending games.
Howard StauntonA Rook is of the value of five Pawns and a fraction, and may be exchanged for a minor Piece and two Pawns. Two Rooks may be exchanged for three minor Pieces.
Howard StauntonFor playing a man to a square to which it cannot be legally moved, the adversary, at his option, may require him to move the man legally, or to move the King.
Howard Staunton