This article explores video game enjoyment originated by games' key characteristic, interactivity. An online experiment (N = 500) tested experiences of effectance (perceived influence on the game world) and of being in control as mechanisms that link interactivity to enjoyment. A video game was manipulated to either allow normal play, reduce perceived effectance, or reduce perceived control. Enjoyment ratings suggest that effectance is an important factor in video game enjoyment but that the relationship between control of the game situation and enjoyment is more complex. © 2007 Mary Ann Liebert, Inc.