The use of game elements as a means to stimulate students' motivation has increased in a number of disciplines across the world after 2010, but apart from a few exceptional cases, it has not been possible to show a significant effect on academic achievement. In this study, the effects of game elements on academic achievement have been investigated among 458 students in a teacher education program, distributed across 10 course instances over 11 years (2010-2020). Statistical analyses indicated that a game element consisting of a number of hand-in assignments contributed significantly to the total points of the final written exam. Although a comparison with the students' results in the two previous modules showed that two thirds of the positive effect could be explained by selection, the remaining one third of the positive effect could still be explained in terms of the game elements significantly improving the achievements on the final written exam.