In this article, we explore the paradoxical relationship between simulation and dissimulation. We draw on nine contributions to an eponymous virtual special issue of Futures to emphasise that overreliance on simulations or their confusion with research methods is associated with the risk of abetting academic or political dissimulation or immunization strategies that escape conventional forms of control or scrutiny. Next, we contend that simulations are mostly forms of knowledge engineering for purposes other than science, before concluding that experiences with simulations and simulation-based policies during the coronavirus crisis might have undermined the higher goals of environmental research, policies, and movements.