BackgroundThe use of serious games in medical education provides a bridge between rapidly developing technology and traditional health-care teaching. Building on a promising web-based serious game for reviewing and acquiring factual knowledge in dental education, the present study investigated the benefits of a dual-player mode and various game options for enhancing knowledge gain and study motivation.MethodsBefore the intervention, students’ dental knowledge and game experience were assessed using a pre-knowledge test and questionnaire-based self-assessment. Students in the clinical study phase (n = 57) were stratified based on prior knowledge and gender and then randomly assigned to two groups, with two player modes: single player (SP) and dual player (DP). In the SP group, each participant played alone, whereas in the DP group, the participants played against a previously determined peer. For a period of 4 weeks, the students were able to playfully acquire knowledge from the field of operative dentistry using METIS, a serious game application with three different game options (Marathon, Sprint, and Time). After the intervention phase, both groups completed a post-knowledge test. The usability of the serious game was evaluated with a self-assessment questionnaire.ResultsThe competitive game mode (DP mode; M = 8.92, SD = 1.85) resulted in an increase in the factual knowledge test that was a mean of 2.49 points higher than the SP mode (M = 5.89, SD = 2.19; p < 0.001). The DP group also found the game significantly more helpful for learning (p = 0.04) and engaged more with the teaching content because of the app (p = 0.04). Overall, the usability of METIS was rated as excellent, and students successfully improved their knowledge of dentistry after game play with both game modes (SP, DP, p < 0.001), with the game option “Marathon,” which involves playing the largest number of questions, being the most preferred.ConclusionsThese results suggest that serious games such as METIS are a suitable educational medium for increasing students’ knowledge and interest in the field, and that competition with peers provides even greater motivation to engage with the learning content.