endgame

1. Games. The final stage of a chess game after most of the pieces have been removed from the board.
2. The final stage of an extended process or course of events: the diplomatic endgame that led to the treaty.

The final stage of some process, as in The book discussed the diplomatic end game resulting in the treaty. This term, dating from about 1880, comes from chess, where it denotes the stage of a game when most of the pieces have been removed from the board. In the mid-1900s it began to be transferred to other activities.

The noun has 2 meanings:

Meaning #1: the final stages of an extended process of negotiation
  Synonym: endgame

Meaning #2: the final stages of a chess game after most of the pieces have been removed from the board
  Synonym: endgame