Simulations Publications, Inc. (SPI) was an influential American publisher of board wargames and related magazines, particularly its flagship Strategy & Tactics, in the 1970s and early 1980s. It produced an enormous number of games and introduced innovative practices, changing the course of the wargaming hobby in its bid to take control of the hobby away from then-dominant Avalon Hill. SPI ran out of cash in early 1982 when TSR called in a loan secured by SPI's assets.