Negotiating has many parallels to the game of chess.
To a chess master, the word gambits implies taking a risk. You put a pawn, a rook, a bishop or a castle out there and you may lose it, but your willingness to take a risk may throw the balance of power in your favor. A chess master would dispute the use of the phrase ending gambits because when you are down to just a few pieces on the board you may not be willing to lose any of them.
As with chess moves, you can learn negotiation gambits in half an hour. Learning when to make those moves may take you a lifetime!