<p>Depression is a common and debilitating mental illness. Internet interventions may be an important tool to address the needs of individuals who are unable or unwilling to pursue traditional care options. Despite the demonstrated effectiveness of Internet interventions, they frequently suffer from low intervention engagement and high attrition. Gamification, or the addition of game-like elements, may be a promising avenue to enhance the likelihood of individuals meaningfully engaging with Internet interventions. In this study, individuals were recruited (mainly via Google Ads) to BetterBET, a fully automated Internet intervention for depression. Of 830 consented individuals who logged in at least once (and therefore learned their randomization condition), 418 were in the gamified version of the intervention and 412 were in the non-gamified version. The self-paced intervention consisted of several interactive lessons about strategies for managing depression based on cognitive-behavioral therapy. Gamification was implemented via badges awarded for certain interactions with the intervention (e.g., logins, mood rating, lesson and follow-up completions). Compared to the non-gamified condition, the gamified condition resulted in a greater number of logins, mood ratings, and follow-ups. Those in the gamified condition were also more likely to use a resource page, a feature not incentivized by badges. No differences were observed in lesson visits or duration. Gamification appears to improve several metrics of intervention engagement and retention. Future interventions should consider thoughtful integration of gamification to foster greater engagement.</p>