Immersion is commonly described by gamers and gamereviewers as an important aspect of a videogame. In this paper, we investigate the relationship between the immersive experience of videogames and the addictive nature of games. Building on Charlton’s (2002) study of addiction and engagement in computing, we conducted a questionnaire study of people who play videogames. It seems that videogames blur the distinction between addiction and high engagement even more than generic computing. In a follow up diary study, the degree of immersion whilst playing was found to be strongly correlated (r=0.763) with the addiction/engagement score. Overall, these studies suggest that the degree of immersive experience is closely related to how addictive or engaging people find videogames and moreover that addiction seems to be an extreme form of engagement and immersion.