In this chapter, we have looked at what a game engine is in general. Simply restated, a game engine is the underlying technology used in writing a game. By employing a game engine, the game designers are free to concentrate on the game play and any applicable story lines within the game. The chapter has also presented the basic design of this sample game engine at a high level. We have also looked at how the game application interfaces with some of the higher-level game engine functions for controlling the flow of the game.