by another enemy piece). Likewise, a piece that is pinned to the king cannot capture the checking piece since such a move would uncover a check to the king. Moving the king. The king is moved to an adjacent square where it is not in check. The king is not allowed to castle when it is in check. The king may capture an enemy piece in a move to get out of check, as long as the piece is not protected. Blocking the check. Also called interposing, is possible only if the checking piece is a queen, rook, or bishop and there is at least one empty square in the line between the checking piece and the checked king. Blocking a check is done by moving a piece to one such empty square. (The blocking piece is then pinned to the king by the attacking piece.) In the position in the diagram, White can get out of check by any of three methods: Capturing the attacking piece by the move Nxa2. Moving the king to any unattacked square (marked with "x"); namely, Kd6, Ke5, or Ke7. Blocking the check by the move Rc4 or Nd5. If a king is placed in double check, the king must get out of both checks on the following move. Since it is impossible to capture both checking pieces or block both lines of attack in a single move, a double check can be escaped only by moving the king. The king itself, however, can capture one of the checking pieces or another enemy piece if it brings the king into safety. If none of these possibilities can remove the check, then the king is checkmated and the game is lost. Types of checks Sometimes a given check is part of a chess tactic such as a fork, a skewer, or a discovered attack on another piece. In some cases, a check can be used to defend against such tactics. There are also a few more special types of check: Discovered check. A discovered check is similar to any other type of discovered attack except that it is a discovered attack on the opposing king. In a discovered check, a piece moves out of the line of attack by another piece so that this other piece (which can be a queen, rook, or bishop) is then checking the opponent's king. A discovered check could be