This introductory chapter provides an overview of the early history of the use of games in architecture and urban planning dating from the late 1960’s and early 1970’s, as well as a broad overview of recent and current use of games for the purposes of: co-design tools in architecture and planning practices; teaching tools in university and other school contexts; and research tools, primarily in academic contexts. Taken together this recent history underscores the rich diversity of games, simulation games, game-like approaches, games scenarios and gamification processes of design, teaching/learning, and research. The 17 chapters that follow are organized into discrete sections that reflect the purpose or combined purposes of the chapters: 1) co-design games; 2) co-design + educational games; 3) educational games; 4) educational and research games; 5) research games; and 6) co-design, educational, and research games. Overall, the book aims to contribute to the clarity, consolidation, and further development of the field.