If one of your pieces is under attack, you will want to defend it.
You already know how to this by moving, capturing or protecting.
Still, there is a fourth way: blocking.
You place another piece between the attacking piece and the piece that’s being attacked. That way, the other player cannot take your piece.
Look at the example.
White’s rook is threatened.
Protecting, moving and capturing are not possible.
How can White save his rook?
By placing his knight between his own rook and the black bishop!
Black’s bishop will probably take the knight. Don’t fret. The king simply takes the bishop in return.
A knight and a bishop are worth the same. So Black gains nothing by it.
Always make sure your blocking piece is protected. Or you will still lose points.
What do you have to do?
One of your pieces is under attack.
Defend it by blocking the attack.