High fidelity simulation has become a popular technique for training teamwork skills in high risk industries such as aviation, health care, and nuclear power production. Simulation is a powerful training tool because it allows the trainer to systematically control the schedule of practice, presentation of feedback, and introduction (or suppression) of environmental distractions within a safe, controlled learning environment. Unfortunately, many within the training community have begun to use the terms simulation and high fidelity simulation almost synonymously. This is unfortunate because doing so overemphasises the instructional technology to the detriment of more substantive issues, such as the training's goals, content, and design. It also perpetuates several myths: simulation fidelity is unidimensional, or higher levels of simulation fidelity lead to increased training effectiveness. The authors propose a typology of simulation fidelity and provide examples of how the different classes of simulation have been successfully used to train teamwork skills in high risk industries. Guidelines are also provided to maximise the usefulness of simulation for training teamwork skills in health care.