Developing a simulation can be both challenging and rewarding. Simulations provide the opportunity for trainees to demonstrate complex behavior, get feedback, and improve performance. The developer will want to conduct thorough analyses of the situation to be simulated, including the job and its requirements, as well as the organization's environment and culture. Theory-based principles from social psychology, cognitive psychology, learning, psychometrics, and gaming/computer science have practical implications for how to construct simulations. These theories provide guidance for the construction of simulation materials aimed at eliciting behaviors relevant to the performance dimensions of interest. Individual simulations can mirror organizational challenges of analyzing information and dealing with interpersonal conflicts. Group simulations can mirror situations in which teams must deal with complex business challenges or interact with other groups. Pilot testing is essential to confirm that the simulation is working well before implementation.