Arena football is a variety of eight-man indoor gridiron football. The game is played indoors on a smaller field than American or Canadian football, designed to fit in the same surface area as a standard North American ice hockey rink, resulting in a faster and higher-scoring game that can be played on the floors of indoor arenas. The sport was invented in 1981, and patented in 1987, by Jim Foster, a former executive of the National Football League and the United States Football League. The name is trademarked by Gridiron Enterprises and had a proprietary format until its patent expired in 2007.

Eight-man football is a form of gridiron football, generally played by high schools with smaller enrollments. Eight-man football differs from the traditional 11-man game with the reduction of three players on each side of the ball and a field width that can be reduced to 40 yards, 13 1/3 yards narrower than the 53 1/3-yard 11-man field. Most states continue to play on a field 100 yards long, whereas a few states opt for 80-yard lengths. Reduced-player football, which consists of eight-man, six-man, and nine-man football has gained popularity across the United States. As of 2015, 1,561 schools in 30 states sponsor reduced-player football, with 1,161 of those teams participating in eight-man leagues, whereas 284 teams play six-man football and 116 teams play nine-man football.