Desperado

In its most common sense, a desperado is a piece that is trapped, attacked without adequate defense, or destined to be lost during a sequence. Instead of making a futile retreat or disappearing without gaining anything in return, the piece captures something, gives check, directly attacking the king, or causes as much damage as possible before the opponent takes it.

Two established uses

• The usual tactical meaning is a doomed piece that captures something or makes the opponent give up an advantage before it falls.
• A more specialized meaning is a piece repeatedly offered for capture to force stalemate. Stalemate is a draw in which the player to move is not in check but has no legal move.

The idea does not justify every last-minute move. You must first verify that the piece cannot be saved usefully and that its final action improves the result. Sometimes the best action is an immediate capture; sometimes it is a zwischenzug that makes the opponent respond before the original sequence can continue.