This book was originally published in 1980. Theoretical physics makes extensive use of models to test and develop intuition. This monograph seeks to provide an introduction to high-energy model making. Its aim is to explain the basic ideas in a form accessible to graduate students and other readers who have acquired a first-hand knowledge of quantum field theory and basic particle physics, including the elements of Regge theory. It describes major calculational techniques together with sufficient physical applications to illustrate their utility. No attempt has been made to be encyclopaedic, for an exhaustive treatment of every application would have created a volume too large for the simple pedagogic purpose intended.