Student nurses, globally, appear to struggle with medication calculations. In order to improve these skills among student nurses, the authors developed The Medication Game--an online computer game that aims to provide simple mathematical and medical calculation drills, and help students practise standard medical units and expressions. The aim of this study was to examine whether baccalaureate student nurses who played The Medication Game as a supplement to lectures and task-solving during a medication calculation course improved their examination results compared to a control group who used lectures and task-solving only. The authors used a randomised controlled design to study 201 students enrolled in medication calculation courses. The main measures were examination results, gaming high scores, the number of gaming self-tests and gaming time. There was no significant difference between groups in examination pass rates: 56% of the control group and 67% of the gamers passed. However, gamers who passed the examination had higher gaming high scores (p < 0.01) and used the gaming self-tests more frequently (p < 0.01) than gamers who failed the examination. The authors concluded that The Medication Game did not significantly improve examination results, but that using the game frequently appeared to influence the examination outcome positively.