Gamification is increasingly applied in contexts where personal performance is of importance. However, the psychological nature of their relation has not been thoroughly examined. The authors investigated how achievement-based gamification impacts attitudinal engagement and performance across 6 university courses. The authors created challenges and badges connected to coursework and measured students' engagement and performance while gamifying the course in 1 year of the 2-year quasi-experiment. In the other year, the authors examined engagement, performance, and would-be-attained achievements were the course gamified. Results show students performed moderately better in gamified condition. Moreover, badges had a guiding effect on students as badge-awarding actions were carried out more in gamified courses. Importantly, the authors found a small mediation effect of engagement in gamification-performance relation. The authors thus conclude badges may be a useful method when gamifying academic performance and that work attitudes are a useful framework to further examine the relation.