Over the past decade, medical simulation has developed to a point where it now is poised to become ubiquitous in teaching curricula. Despite this experience, there is little up-to-date information to help new instructors and operators learn the general principles of simulation. The purpose of this article is to provide prospective simulation instructors with basic concepts and a practical approach to patient simulation. The main focus is on full-scale or high fidelity simulation. The article is intended to (a) prepare instructors to use fullscale simulation to educate students; (b) teach some of the complexities and terminology of simulation; (c) prepare for and complement the curriculum of a formal instructor course; and (d) teach the basic elements required to run a successful simulation. This article should be used as an adjunct to practical experience gained from using simulation units.