Indoor football is a type of American Football played indoors in arenas. The arena used for indoor football is smaller than that used in regular American football and a regular football game played indoors is therefor not an “indoor football” game.
The history of indoor football starts in 1902-03 when the world series of pro football was played inside the Madison Square Garden. This was the first ever national professional football league in the US and was in a way the predecessor to the NFL. The games where played using a field that was smaller than that normally used in football, only 70-yard by 35-yard. The Tournament folded in 1904.
After that no major indoor football games were held until 1932. In 1932 severe blizzards prevented the NFL playoff games from being played outdoors and an indoor field was setup inside the Chicago stadium for the games. Several other attempts was made with indoor arenas and indoor games to prolong the season but nothing would really catch on and almost no real indoor football would be played until the 1980 s when the game as we know it now started to develop. The modern history of indoor football is closely linked with that of Arena football, an indoor football league founded by Jim foster. In 1986 after the collapse of the USFL he staged a 4 team demonstration season played in spring 1987 with televised games. The demonstration season was a success and the league would operate for 22 years after that.
To make the game fit better to indoor arenas Foster changed the field size to be the same measurements as a hockey rink and reduced the number of players on the field from eleven to eight. Out of these eight players at least 6 had to play both defense and offense. This was partly to reduce team size and payrolls. Other rules changes includes disallowing punting, the only kicking option in arena football is to try for a field goal. He also added rebound nets at the ends of the field. If a ball is kicked or thrown onto these nets and bounce back they are still in play and the net can hence be used for passes. If a pass bounce of the net the ball stays alive until it touches the ground, if it bounces after a kick the ball stays alive even after it hit the ground.
Foster also placed a lot of rules on the defense to promote more action in the game. Linebackers are not allowed to blitz and need to stay behind the line of scrimmage. A 3-2-Monster formation (three defensive linemen, two linebackers, two cornerbacks, and one safety) is mandatory for defensive play.7
Soon after the formation of the AFL Arena football league the first competitor, the world indoor football league was formed. This was just the first of the many attempts that has been made to compete with area fotball league over the years. The WIFL folded almost immediately.
Foster patented his game in 1990 to prevent other league from using his rules or the name arena football. The difference between arena football and indoor football is in other words that arena football is a protected term used by one league while the term indoor football is free to use. The exact rules also differs slightly. The patent expired in 2007 and anyone can now use the same rules and rebound nets freely.
Arena football saw many successes during its lifespan such as the signing of a major television contract with the NBC and the development of a minor league, AF2, where developing teams could play and where players could get used to the sport before joining a major team. In the end however many of the teams had been poorly managed. Cost and salaries had been allowed to raise to a level where it was no longer sustainable and the Arena Football league therefore folded in 2009.
The AF2 did however still do well due to lower wages and since the AF owned 50.1% percent of the AF2 hey would go under as well if the AF folded. To solve this the teams in AF2 formed a new organization, the AF1. This organization bought out all assets relating to AFL and AF2 owned by AFL and they then adopted the name arena football league shortly after the bankruptcy of the original AFL The new league is at the moment doing well with 19 teams playing the 2011 season.
Other indoor football leagues includes the AIFA that you can read more about on this site, the Indoor Football League and the southern indoor football league as well as several others.
Indoor football is still very much a sport under development and it will likely take some time before a dominate premier league appears such as the NBA, NFL and NHL.