Speed Circuit was an Avalon Hill game (previously published by 3M), currently (2009) out of print. The 3M edition featured the grand prix circuits of Monaco, Monza and Watkins Glen. and was first published in 1971. Its solid body of rules allowed many optional house rules. Also, many players could be involved, with races of up to twelve cars usually being very competitive and rewarding for the players. Another advantage was the release of extra tracks by Avalon Hill, to allow the running of championship seasons, and the relative facility for players to design their own tracks.