Simulation games, antedated by war games such as CHATURANGA and chess, are still in an early stage of their design, development, and use for the classroom. Evidence of their learning advantages is little and uncertain; but their users, students and teachers, are enthusiastic; and they may become an integral part of the K-12 curriculum. Simulations will have greater value if followed by discussion and if students build their own games. Operating models of physical and social situations tend to simplify reality and may or may not change attitudes in ways that may be positive or may be negative. Logistics affecting games usage are space and time allotments and low availability of suitable games. INTER-NATION SIMULATION, MARKET, COMMUNITY RESPONSE, and other representative social games are described in the text. Additional games are listed at the end with descriptions and grade leveling within subject fields. Resource organizations are noted, as well as current books, articles, reports, and films on simulation. (AW/MF)