Background: Constructing shared understanding of complex interdisciplinary problems is one of the most challenging aspects of interdisciplinary teamwork. How this process unfolds is under-researched, making it esoteric and difficult to scaffold. This paper aims to provide an articulated and nuanced account of what is involved in student teams' construction of shared understanding of complex interdisciplinary problems. Methods: The study combines the theoretical lens of epistemic games with an ecological analytical perspective. Drawing on the analysis of ethnographic cases, it explores how four graduate student teams construct shared understanding of complex problems during interdisciplinary projects. Findings: Construction of shared understanding is a multifaceted and dynamic process that extends over the entire problem-solving activity. It relies on epistemic moves that explicate and juxtapose different perspectives and connect abstract ideas with knowledge grounded in students' experiences and contexts. The pursuits students engage in, when creating shared understanding, reveal epistemic differences related to formulation of the interdisciplinary problem and what constitutes trustworthy knowledge. Contribution: The paper contributes to the literature on the nature of students' construction of shared understanding of complex interdisciplinary problems revealing critical recurrent moves. It also extends earlier conceptualizations of epistemic games as primarily discourse games and demonstrates that they are profoundly multimodal and distributed.