Or, he can block the check with his Queen or one of his Knights. Now, Black can move his King to f8 or d7, but not to e7, because he would still be in check. Do you see the seven different squares that the Bishop can move to with discovered check? Yes! If White's black-squared Bishop moves, the newly opened file exposes Black's King to an attack from White's Queen! That is called a 'discovered check'. What about the Queen? Can she do anything? The white-squared Bishop can take Black's f7 Pawn with check, or move to b5, also checking Black's King. the Knight can check two different ways, Nxg7+ and Nxd6+. In this (very) complicated position, how many different ways can White check Black's King? Lets count them.

Remember: Any move that exposes your King to an attack from any of your opponent's pieces is illegal. Actually, this is illegal, because it would place the White King in check from the Rook. At first glance, it would look like White's King can capture the Queen. In chess notation, check is written as a '+' sign, and checkmate is '#' or '++'. If you can't do any of these things, you're checkmated, the game is over, and you lose. In the opposite diagram, White's only option is to move his King to one of the highlighted squares. There are three ways to get out of check: move your King, block the check with another piece (this can't be done against knights, because they would simply jump over the blocker), or take the checking piece.

It is called 'check' when you or your opponent's King is attacked.

King and queen mate