Simulation aims to reduce the discrepancy between training and professional reality, creating a safe learning environment that allows learners to focus fully on the task at hand. This manual presents the various facets of simulation for control centers, fire departments, emergency services, and hospitals. Starting from the objectives of simulation, it addresses teamwork and communication, error culture, and theoretical learning backgrounds. The focus is on the planning and execution of simulations and the debriefing process, which are explained in a target-group-oriented manner and illustrated with example scenarios and checklists. Various practical references are intended to facilitate the transfer to the readers' own reality. The manual provides insight into simulation as a methodological spectrum for all participants along the rescue chain.