Introduction: Pharmacy students in the United Kingdom (UK) need to efficiently navigate the British National Formulary (BNF), a standard medicines reference source. "Pharmacy Challenge" is a web based prototype game based on the BNF. This research aimed to evaluate the game in terms of design, content and impact on students' performance and confidence. Methods: Evaluation comprised three phases: implementation, perception and impact of a serious game. Game design and evaluation methods were modelled using adapted elements of the RETAIN framework. Qualitative and quantitative questionnaires were utilised to assess students' perceptions of the game and its role in their education and to evaluate changes in confidence and performance experienced by students after playing the game. Quizzes were developed to determine changes in performance through comparison of scores before and following game use.Results: The questionnaire evaluation (n=152) found students' confidence increased significantly (p<0.05) in: speed of using, knowledge of BNF sections, extracting information and knowing where to look for the answer. Students (88%;106/120) felt they had learnt something new, 86% (103/120) felt that it reinforced their learning. A significant (p<0.05) increase in pre and post BNF quiz marks was observed (n=33).Conclusions: Statistically significant improvement in students' perceived confidence was noted. The study identified design elements such as the need for a simple interface to encourage engagement.The prototype has undergone a design transformation based on the feedback provided and is now released under the name "DOSE" with a bank of 300 questions, improved graphics, a leadership board and medals.