This chapter introduces procedural content generation (PCG), and presents a comprehensive taxonomy of content types, methods, and roles. PCG can be used for a large variety of content types, including quests, textures, terrains, items, characters, and game rules. However, 2D and 3D levels and maps are the most common types of generated content. PCG methods can be used on their own or to assist players and designers, and during game development as well as during the game’s runtime. The various methods used differ in many respects, among others how controllable and how fast they are, and whether they give guarantees as to the playability of the content.