subgame

plural subgames

1. computingA subset of a game that can be considered a game in its own right.

   A subgame is a piece of a game—the piece that remains to be played beginning at any point at which the complete history of the game thus far is common knowledge among the players.

   1992, Robert Gibbons, A Primer in Game Theory, Prentice-Hall, page 94

2. video gamesA minor or incidental game within a larger video game; a minigame.

   There was a subgame that was very well-recieved ^([sic]) in the previous Paper Mario RPG [Paper Mario: The Thousand-Year Door], where you would play through this side-scrolling stage as a gigantic Bowser.

   2007, Nintendo Power, volumes 214-216, page 78