The word "endgame" refers to the point in a chess match at which it becomes clear to both players that one is going to win. Nevertheless, both must go through the necessary motions of playing out the last moves that will lead to the inevitable checkmate of one player's king. Some players might drag the ending out as long as possible, while more experienced players might just get the game over with as quickly as they can.

The title refers to the characters living in a time where the end of the world is coming, as well as the end of their lives. As with the losers in a chess game, these characters are simply going through the motions, each day in their lives like another chess move in a game that can't be won.

Endgame is an apt metaphor for the play, as life is treated as a game and the characters as if they are actors, like Hamlet, playing a part. Endgame thus captures both the idea of an inevitable bad ending and the idea of play. Play is important, because a chess game is both completely trivial, a way to pass the time that usually (if one is not a competitive chess master) does not matter in the grand scheme of things, but it can seem all important while it is going on, even when the outcome is known. This duality becomes Becket's metaphor for life, both meaningless and yet seemingly of greatest significance.