Discovered Check
A discovered check happens when one piece moves away and uncovers a rook, bishop, or queen line to the enemy king.
What to look for
Look for your line piece aimed at the king through one of your own pieces. The moving piece may create another threat, but it does not have to.
Recognize the mechanism
Locate the line to the enemy king before moving the blocker. The uncovered check forces a response while the moving piece may capture, threaten or improve its position. Calculate legal king responses rather than assuming the second threat wins immediately.
Common practical mistake
The piece that moves need not give check itself. If it also checks, the position is a double check; keep these related ideas distinct.
Training goal
Use check tempo to win material, force mate, or improve the attacking piece.