Don't hang your OWN pieces

Vision protects you too.

Piece vision points both ways. Before you commit to a move, look at your OWN pieces: is anything attacked and undefended? It's heartbreaking to lose a rook because you were busy with your own plan and never noticed it was under fire.

In the diagram, the black bishop attacks White's rook on e1, and no white piece defends it — your rook is hanging. You can't ignore it: move the rook to safety or defend it. Checking your own loose pieces before every move prevents most beginner blunders.

The bishop attacks White's undefended rook on e1 — it's your piece that's hanging now.

Your rook is attacked by the bishop and nothing defends it. The safe reply is to:

Answer the question to keep going!