Introduction: Workplace-based assessment occurs in authentic, dynamic clinical environments where reproducible, measurement-based assessments can often not be implemented. In these environments, research approaches that respect these multiple dynamic interactions, such as complexity perspectives, are encouraged. Previous research has shown that fairness in assessment is a nonlinear phenomenon that emerges from interactions between its components and behaves like a complex adaptative system. The aim of this study was to understand the external forces on the complex adaptive system which may disrupt fairness from emerging. Methods: We conducted online focus groups with a purposeful sample of nineteen academic leaders in the Netherlands. We used an iterative approach to collection, analysis and coding of the data and interpreted the results using a lens of complexity, focusing on how individual elements of fairness work in concert to create systems with complex behaviour. Results: We identified three themes of forces which can disrupt fairness: forces impairing interactivity, forces impairing adaption and forces impairing embeddedness. Within each of these themes, we identified subthemes: assessor and student forces, tool forces and system forces. Discussion: Consistent with complexity theory, this study suggests there are multiple forces which can hamper the emergence of fairness. Whilst complexity thinking does not reduce the scale of the challenge, viewing forces through this lens provides insight into why and how these forces are disrupting fairness. This allows for more purposeful, meaningful changes to support the use of fair judgement in assessment in dynamic authentic clinical workplaces.