A discovered attack opens a line by moving a blocking piece. The moving piece can create a second threat if its destination is useful.
What to do
Identify the concealed line and the blocker. Calculate destinations that create checks, captures or another concrete threat while uncovering the original attack.
A mistake to avoid
Do not move the blocker simply because a line opens. The revealed target may be defended or able to move with tempo.
A detail worth checking
Notice whether the discovered attack is a check. That changes the opponent’s legal response options and can make the moving piece’s second threat more powerful than a similar-looking nonchecking discovery.
Try this practical check
In a verified exercise, compare two destinations for the blocking piece. Explain why one creates a stronger combined threat even though both reveal the same line.
Related reading
6 Best Chess Books for Beginners and Improving Players (2026)
