In 1981, George MacDonald and Steve Peterson, from San Mateo, California, printed 1,000 copies of a 64-page rule book for Champions, their super-hero role-playing game, to take to a Bay Area gaming convention. It sold very strongly, enough to form a company, Hero Games. The firm published games which utilized the hero system, its own set of generic roleplaying rules which could be used to simulate many different games. The Champions role-playing game proved most successful for Hero Games. This series utilizes the hero system and has endured through to the 21st century, although Hero Games has undergone many changes in ownership and staff.