As virtual and mixed reality (VR/MR) technology moves steadily towards general availability accessible descriptions of the surrounding theory is desirable. An initial focus on high-level concepts can provide common language for diverse teams, including artists, designers and engineers, helping them to quickly get a sense of basic principles and gain a familiarity with related research for further study. The concepts of synchronized reality and grounded simulation are introduced as helpful starting points for thinking about the design and development of mixed reality systems with optimal presence. This paper provides case studies where recent commercial VR applications are analyzed with the proposed principles in mind, in an attempt to illustrate to developers how to think about design of mixed reality games for optimal presence. © 2019 ACM.