Jason Gregory's book is a bestseller for a reason. The author's twenty years of work on top-notch games at Midway, Electronic Arts, and Naughty Dog provide insight into the theory and practice of game engine software development. Game programming is a complex and vast topic that covers a lot of ground. The line between a game engine and a game is blurred. This book focuses on the engine, core low-level systems, collision resolution systems, physics simulation, character animation, audio, and the core gameplay layer, which includes the game object model, world editor, event and scripting systems.