Galloway attempts to focus the broad concept of video games by separating the concepts of machine action and operator action. Using examples from a variety of game types, Galloway describes an operator action as an action or decision made solely by the player, such as finding a power up in a game. In contrast, a machine action is routed in the basic programming of the software, such as the increase in health that the power up supplies the character. He also defines video games within diegetic and nondiegetic terms. Diegetic play elements are the onscreen and off-screen elements of the game. Nondiegetic play elements are external to the narrative action. Using these four parameters, Galloway is able to categorize various video games.

It is interesting to note how these parameters have evolved as the complexity of video games have increased. The gamer-machine interface was much more direct in a game like Asteroids, where the player had to rotate and shoot. More modern games, such as Halo, expand into more diverse range of motion and controls as well as the broad spectrum of online play. As these games have changed over time, I wonder whether it is the operator or the machine that is gaining more control over the game environment. Surely the machine has increased in power and capability, but the operator’s control over his environment has grown exponentially. The machine is, of course, still in control over the operator by restraining the operator’s movements to within the constrains of the game. However, the operator has more choice in his actions within these constrains.