Speculative Enactments are a novel approach to speculative design research with participants. They provide a means for the empirical analysis of participants acting amidst speculative but consequential circumstances. The approach is contextualised within the field of Human-Computer Interaction (HCI), which as a broadly pragmatic, experience-centered, and participant-focused field is well placed to innovate methods that invite first-hand interaction and experience with speculative design projects. We’ve developed and refined the Speculative Enactments approach in multiple projects – and in a ACM CHI 2017 paper, we discuss three case studies of this approach in practice, based on our own work: Runner Spotters, Metadating and a Quantified Wedding. In the paper defining and reporting on the approach, we offer not just practical guidelines, but a set of conceptual resources for researchers and practitioners to critique the different contributions that speculative approaches can make to HCI discourse (and design research more broadly).