Abstract Interactive digital narratives (IDNs) create alternate realities using both fictional and non-fiction material. The interactive aspect of IDN turns audiences into participants and enables the exploration of alternative perspectives and actions within a single artifact. Such multifaceted representations make IDN a vehicle for representing complex issues, a crucial capability at a time when the limits of traditional narrative media to adequately represent complex issues such as climate change become apparent. Conversely, properly evaluated, generalized knowledge about how exactly IDNs engage and influence us and what this means for the design of such works is still scant and thus this topic needs scholarly attention. In this overview paper, we discuss the potential of IDN, but also the difficulties of realizing this potential in terms of design and of verifying the effectiveness through empirical research methods. The potential of IDN as dynamic, participatory, and encyclopedic artifacts can be clearly expressed, yet the same cannot be said when it comes to the design and especially the evaluation of intended prosocial effects, the topic this paper is focused on. We start by identifying the problem of IDN design resulting from a combination of the lack of generalized knowledge and formal professional training. Then, we discuss the challenge of measuring the effectiveness of IDN design for prosocial effects and report on several case studies. In this context, we discuss methodological issues and advocate for best practices. Finally, we consider future steps in addressing the continuing challenge of evaluating IDNs.