Gridiron Australia and Gridiron West operate under the rules as set out by the International Federation of American Football (IFAF). These rules are have been adapted from NCAA rules and vary from the rules used in the NFL. Here are some of the key differences between NCAA and NFL rules:

The Playing Field

The field dimensions are the same ? 100 yards long (plus 10 yard end zones, making 120 yards in total) by 53 1/3 yards wide ? but the placement of the hash-marks ? those white dashes in the middle of the field ? are different. On an NFL field, the hashes are much closer together; they are aligned with the uprights of the goal post. The college game sets them much wider apart. This may not seem like a big deal, but it actually does affect the game. After each play, the ball is spotted on one of the hashes or in the middle of the field, depending on where the previous play ended. For example, if a ball-carrier is pushed out-of-bounds on the right sideline, then the ball will be spotted on the corresponding hash-mark on the right side of the field.?For a college team, that means they have a very wide expanse of field to use on one side and a rather narrow area in which to operate on the other. It also has a huge impact on field goals since the wider hash produces much greater angles for the kickers to deal with than those faced by NFL kickers.

How Players are Ruled Down

Perhaps the most glaring difference between the college and pro games is how players are ruled ?down?. In the NFL, a player is down when he is either on the ground and touched by an opposing player or goes to the ground as a result of contact with an opposing player.?In college, a player is down whenever a part of his body other than his feet or hands touches the ground, regardless of whether or not he was touched by an opposing player. What that means is that if an NFL player falls to the ground without being touched?say after making a diving catch or losing his footing?he can get back up and keep running because the play is still live. In college, he?d be down. There are some exceptions: in college, the holder on a field goal try is not considered down when he receives the snap even though his knee is on the ground; in the NFL, a quarterback is considered down when he kneels after taking a snap in order to run out the clock. Also, a kick returner can kneel in the end zone for a touchback and cause the play to be blown dead.

Possession After the Catch

In the NFL, a player who is receiving a pass must do several things before they establish possession of the football. First, they need to get two feet down inbounds. Next, they need to continue, throughout the process, to retain a firm, controlled grasp of the football. Lastly, they have to make what is referred to as an ?athletic move? with the ball in their possession. With NCAA rules, on the other hand, players need to do far less to establish possession. Essentially, all they need to do is to get one foot down inbounds and retain a grasp on the football. By doing so they prove that they have possession.

Pass Interference

Speaking of receivers, the college game differs from the NFL in the penalty it assesses for pass interference.?In the NFL, pass interference is a spot foul; the ball is spotted where the interference occurred. Under NCAA, if the spot of the foul is less than 15 yards from the Line of Scrimmage then it is a spot foul, if the spot is greater than 15 yards, it is only a 15 yard penalty. A first down is rewarded in both cases.?For instance, let?s say the offense has the ball at its own 30-yard line, and the quarterback throws the ball deep. The defender commits pass interference at his own 20-yard line.?In the NFL, the ball is placed at the 20, resulting in a 50-yard gain for the offense.?Under the NCAA rules, the ball would be placed at the offense?s 45, a gain of only 15 yards.

Clock Rules

Both the NCAA and NFL use different clock rules. The NCAA stops the clock whenever a first down is achieved so that the chains can be reset. Once they are in place, the clock resumes. In the pro game, the clock keeps running.?That has huge implications at the end of games when time is short.?A team can afford to throw the ball over the middle of the field because the clock will briefly stop. An NFL team doesn?t have that luxury because the clock keeps running.?On the flip side, there is no two minute warning in NCAA football. Contrastingly, in the NFL, time is stopped and players are warned when two minutes remain in either half. This also offers a free time-out to both teams before the end of the first half and the end of the game, which is a large part of what is commonly referred to as the ?two-minute offense.?

Two-Point Conversion

The NFL and NCAA both give their teams the option of going for two after scoring a touchdown, but the former places the ball at the two-yard line while the latter spots it at the three.

Point After Touchdown

In NCAA football the PAT is attempted from the three-yard-line. In the NFL it?s the fifteen-yard-line.

Two Points for the Defense

Under the NCAA rulebook, the defense can return a turnover for two points during a PAT attempt. In professional football, the offense?s loss of possession simply ends the PAT attempt altogether.

Penalty Enforcement

In the NFL, defensive holding will get you 5 yards and an automatic first down whereas under the NCAA rules, it?s 10 yards but not an automatic first down.