In the present study, the interplay of player performance, game-related self-efficacy experiences, and the resulting effects on game enjoyment are investigated. We hypothesized that a player's performance stimulates enjoyment via its potential to stimulate game-related self-efficacy experiences. In a laboratory setting, participants (N = 213) played a jump 'n' run game. Their performance during game play was recorded by log-file software, and efficacy and enjoyment were assessed with questionnaires. As predicted, both player performance and game-related self-efficacy experience were significant predictors of enjoyment. Furthermore, the results demonstrate that game-related self-efficacy experience significantly mediates the relationship between player performance and game enjoyment.