Decoy / Deflection
An underestimated tactic which if studied and added to a chess player's armoury of tactics will make them a dangerous adversary.
This puzzle comes from a position between Capablanca and Fonaroff New York 1904. It is in fact a brilliant tactical combination by Capablanca which includes a decoy tactic, which is a critical element in the combination which nets a piece.
An expanding list of tactic trainer links to puzzles which involve the decoy tactic.
http://www.chess.com/tactics/?id=25158 Capa's game