In an era characterized by rapid technological advancements and shifting workforce dynamics, it is necessary for organizations to upskill and reskill employees. As a result, a rapidly increasing number of companies worldwide is investing in educational technologies such as gamified training. However, despite the growing interest in gamified workplace training tools, the literature lacks empirical research on their design principles, effectivity and long-term impact. This has caused gamified trainings to fail and many resources to be lost. This research seeks to address these issues by investigating how to ensure successful (i.e. ‘meaningful’) gamified training tools. We aim to provide practical guidelines on how to design and implement meaningful gamification that has the potential to increase training effectivity, while boosting employee engagement. Based on a mixed-methods approach with both field experiments and interviews, the characteristics of meaningful gamified training apps will be determined, as well as the effect on employee engagement and knowledge retention. In addition, we aim to provide novel, actionable guidelines for increasing adoption of gamified training apps through nudging. By contributing to the emerging stream of research on gamified workplace training tools, this study aims to provide valuable insights for both practitioners and researchers, ultimately enhancing employee engagement and knowledge retention in knowledge-intensive industries.