Classic chess rules

Check

When a player makes a move that threatens the opposing king with capture (not necessarily by the piece that was moved), the king is said to be in check. The definition of check is that one or several opposing pieces, if moved to one of the spaces allowed by the normal patterns of movement for that piece, could theoretically capture a piece in the kings space (that is, capture the king, itself) on the next move. If a player's king is in check then the player must make a move that eliminates the threat(s) of capture; a player may never leave his king in check at the end of his move. The possible ways to remove the threat of capture are:

• Move the king to a square where it is not threatened.
• Capture the threatening piece (possibly with the king, if doing so does not put the king in check).
• Place a piece between the king and the opponent's threatening piece. This is impossible if the threatening piece is a knight or pawn.

In the case of double check, when there are two pieces attacking the king, only a king move will will get out of check; the king may capture an eney peice.

In informal games, it is customary to announce check when making a move that puts the opponent's king in check. However, in formal competitions check is rarely announced (Just & Burg 2003:28).

A player may not make any move which places or leaves his king in check, even if the checking piece can not move due to a pin. This also means that a player cannot place his king on any square adjacent to the enemy king, because doing so would leave his king able to be taken by the enemy king and therefore in check.