“Perfection is not attainable but if we chase perfection we can catch excellence� (Lombardi, as cited in Carlson, 2004). In the education and simulation design communities the deliberations continue which are centered on how much fidelity is enough or too much. This paper presents findings from a research project which explored the way in which fidelity influences the sense of immersion and presence and the subsequent perceived benefit to the transfer of learning to the field of application in police training for high-risk high-stakes decision-making. The unique feature of the study is the inclusion of two case studies, one of which utilizes low physical fidelity and high psychological fidelity with participants who are seasoned field based police operatives. The second simulation based learning exercise environment and scenario embraced high levels of physical and psychological fidelity with participants who have nil or limited operational experience in the real world of policing. The common criterion for the two simulation exercises is a pivotal catalyst which requires decision-making in providing a police response to a high risk incident. The findings suggest that a key design feature in the development and application of simulation-based learning environments and exercises is the level of prior real world experience the learner has with the simulated environment. This case study offers insight into the value learners place on the simulation characteristics in representing the real world environment and how this influences the application of knowledge and skills in their real world of policing the streets. Understanding the influence on field based application of simulated learning environments offers a valuable contribution to the instructional design endeavours for creating authentic situated learner experiences.