The NFL Rules Quiz!

There are 11 players on the offense. The offense is the team that has possession of the ball and tries to advance down the field.

That's right. There are as many players on the defense as there are on the offense. Makes sense, right?

The field is exactly 100 yards long, not including the end zones. It's also 53.3 yards wide. Yard markers help the players and officials track the ball.

The end zone is 10 yards long on each end. This is in addition to the 100 yards of the playing field.

There are four quarters comprised of 15 minutes each. That means that the total playing time is one hour, without overtime.

Similar to the beginning of the first quarter, the beginning of the third quarter starts with a kickoff. Possession goes to the team that did not kickoff in the first quarter.

According to the rulebook, halftime is only 12 minutes long. But is that long enough for Katy Perry to sing? No! Super Bowl halftime is longer.

The clock stops when a player goes out of bounds. It also stops when a penalty is called or when a pass is incomplete.

Sudden death overtime is determined by a coin toss. Whoever wins has possession of the ball. Overtime lasts for 15 minutes.

There are three units of players. There is the offense, the defense and a special team for kicking situations.

Kickoffs used to take place at the 30-yard line, but in 2011 the kicking tee was moved to the 35-yard line in order to produce more touchbacks. The placekicker kicks the ball to the offense.

The offense has four downs, or chances, to make a 10-yard gain. Once they accomplish that, they receive first down and four more chances to do it again.

The line of scrimmage is where the play begins. The play begins with a snap, where the QB calls out a play in code, and the player in front of him snaps the ball under his legs.

There are only two choices that the quarterback has, in order to advance the ball. He can either run it or pass it. Running that ball can be done by the running back or by the quarterback himself.

According to the rulebook, anyone on the offensive side can pass the ball. They must be behind the line of scrimmage.

If one or two knees go down, then the player has been tackled. If he was carrying the ball, this means that the play is officially over.

There are four ways to score points in football. These include: Touchdown, Extra point, Field goal, and Safety. The extra point, or conversion, can become a two-point​ conversion if the ball is passed instead of kicked.

Both the fumble and the interception are considered turnovers, moving the ball from the offense to the defense. The defense is able to score a touchdown after a turnover.

Roughly similar, though slightly different, the NFL and the NCAA have different rulebooks. This applies to high school football as well.

Teams switch ends after each quarter. This evens out any advantages or disadvantages that may exist on the field or due to weather conditions.

Each team is only allowed three time outs per half of the game. Exceptions are allowed for injured players.

The offense must begin its next play within 40 seconds of the end of the last play. This is closely monitored by back judges.

A football weighs approximately 14 to 15 ounces. It is always made of leather in professional football and resembles a rugby ball.

Umpires are a part of the team of officials on the field. They're responsible for spotting the ball at the beginning of plays.

The referee has the final say in all decisions on the field. The officiating team also includes the line judge, back judge, and side judge.

It's the duty of the offensive lineman to block the defense, protecting the quarterback and the running backs.

It's the job of the defensive lineman to down the quarterback. He's supported in this task by the linebackers.

They are not the same, but there are some overlaps. The place-kicker does the kick-off and is also trained to kick field goals. The punter is used in the fourth down if it seems like the team will not progress further.

A touchdown is achieved when the ball is carried into the opposite team's end zone. It is worth six points, and an extra point can be achieved with a field kick.

It's unlikely that a team will go for a 2-point conversion, as it's difficult to carry to the ball into the end-zone again. A field kick is opted for in most cases.

A safety is worth two points. It's achieved by the opposite team when a player is downed or causes the ball to go out of bounds while he is standing in his own end zone. This is not awarded if the ball was kicked to the player in question.

If an illegal action occurs on the field, the officials will determine if it's a 5-, 10-, or 15-yard​ penalty. This is determined by the severity of the action.

For very aggressive actions on the defensive team, it can result in the offensive team receiving a first down. The ball is spotted in the appropriate place and playing is resumed.

These are both methods of illegal blocking. The first results in fifteen yards and the second results in five yards.

Roughing the snapper is a serious offense, and considered far too aggressive. This offense is often given a first down.