Football is football, whether played by 11 men on a side or by eight, as in the Arena Football League. It's still running, passing, blocking, tackling and scoring touchdowns.
But there are distinct rules differences between football played in the NCAA and NFL, and the Arena league.
Arena games, as the name indicates, are played indoors. The field is 50 yards long and 28 yards wide with eight-yard end zones. Outdoor football fields are 100 yards long, 53 1/2 yards wide and have 10-yard end zones.
Goal posts in Arena football are nine feet wide, the crossbar 15 feet high. There is rebound netting--30 feet wide and 32 feet high--attached to each side of the goal posts. A kickoff or missed field-goal try that rebounds off the netting is a live ball that can be recovered by either side. A pass that rebounds off the netting is a live ball too and in play until it touches the playing surface.
Arena teams play 15-minute quarters and there is a 15-minute halftime. The clock stops for penalties, injuries, out-of-bounds plays and incomplete passes in the final minute of each half.
A kickoff untouched and out of bounds is put on the 20-yard line or where it went out of bounds, whichever is more advantageous to the receiving team. If it's touched, play starts where it went out of bounds.
Arena teams have four downs to gain 10 yards but there is no punting. If the offense has not made 10 yards after three plays, it must try another play or attempt a field goal.
In the eight-man Arena game, players play offense and defense, with the exception of the kicker, quarterback, an offensive specialist--a receiver or kick returner--and two defensive specialists, usually cornerbacks. The offense must have at least four players on the line of scrimmage.
On pass plays--which constitute 90% of Arena plays--receivers only need one foot inbounds. Runners or receivers also can use the restraining barriers to stay inbounds, as long as their feet don't touch the out-of-bounds line.
Scoring basically is the same as in outdoor football but in the Arena game, teams can score four points on a dropkick field goal.
Each team gets one possession to score in overtime. If the teams are still tied after each has had a possession, play goes to sudden death.