In assessment and selection, organizations often include interpersonal interactions because they provide insights into candidates' interpersonal skills. These skills are then typically assessed via one-shot, retrospective assessor ratings. Unfortunately, the assessment of interpersonal skills at such a trait-like level fails to capture the richness of how the interaction unfolds at the behavioral exchange level within a role-play assessment. This study uses the lens of interpersonal complementarity theory to advance our understanding of interpersonal dynamics in role-play assessment and their effects on assessor ratings. Ninety-six MBA students participated in four different flash role-plays as part of diagnosing their strengths and weaknesses. Apart from gathering assessor ratings and criterion measures, coders also conducted a fine-grained examination of how the behavior of the two interaction partners (i.e., MBA students and role-players) unfolded at the moment-to-moment level via the Continuous Assessment of Interpersonal Dynamics (CAID) measurement tool. In all role-plays, candidates consistently showed mutual adaptations in line with complementarity principles: Affiliative behavior led to affiliative behavior, whereas dominant behavior resulted in docile, following behavior and vice versa. For affiliation, mutual influence also occurred in that both interaction partners' temporal trends in affiliation were entrained over time. Complementarity patterns were significantly related to ratings of in situ (role-playing) assessors but not to ratings of ex situ (remote) assessors. The effect of complementarity on validity was mixed. Overall, this study highlights the importance of going beyond overall ratings to capture behavioral contingencies such as complementarity patterns in interpersonal role-play assessment. (PsycInfo Database Record (c) 2024 APA, all rights reserved).