This book is a compilation of much of the material I used for various game theory courses over, roughly, the past two decades. The ?rst part, ThinkingStrategically, is intended for undergraduatestudents in economics or business, but can also serve as an introduction for the subsequent parts of the book. The second and third parts go deeper into the various topics treated in the ?rst part. These parts are intended for more mathematically oriented undergraduate students, or for graduate students in (for instance) economics. Part II is on noncooperative games and Part III on co- erative games. Part IV is only a mathematical tools chapter. Every chapter has a ?nal section with problems. Selected hints, answers, and solutions to these pr- lems are given at the end of the book. Complete solutions can be obtained from the author. The book claims neither originality nor completeness. As to originality, the material draws heavily on game theory texts developed by many others, often in collaboration. I mention in particular Jean Derks, Thijs Jansen, Andres Perea, Ton Storcken, Frank Thuijsman, Stef Tijs, Dries Vermeulen, and Koos Vrieze. I am also greatly indebted to a large numberof introductory, intermediate, and advancedtexts and textbookson game theory, and hope I have succeeded in giving suf?cient credit to the authors of these works in all relevant places.