A pin can restrict a piece because moving exposes the king, or create a tactical problem by exposing something else valuable.
What to do
Identify the attacking line, the pinned piece and the object behind it. Check whether moving is illegal or merely costly, then calculate captures and ways to break the line.
A mistake to avoid
Do not assume every pinned piece is helpless. It may capture the attacker, be defended or create a stronger threat elsewhere.
A detail worth checking
Look for ways the pinned side can change the line itself. Moving a king, exchanging the attacker or interposing another piece may alter the tactical situation without moving the apparently restricted piece.
Try this practical check
Use two verified pin exercises, one against a king and one against a valuable piece. State the legal difference before solving either position.
Related reading
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