A Beginner's Guide to American Football

American Football may be built upon basic principles, though even the most avid fans in the stands may not know every single rule. The aim of the game is like any other sport - to score the most points - but it's extremely unique and complicated in how this is achieved.

Despite the complexity, both National Football League and College games garner some of the biggest audiences the sporting world has ever seen.

With a 'start/stop' style of play, various teams on both sides of the ball, nearly 100 different penalties and over 50 players on each sideline, American football can seem understandably confusing to those wanting to watch, play or simply bet on the sport.

Not to worry though, we're here to help!

We'll be running through everything you need to know to understand exactly what's going down on the football field.

The Basics

Each team consists of a maximum of 53 players, with 11 on the field at a given time.

Both sides will have 11 starting players for their offence and 11 for their defence. The other 31 players will be back-ups for offensive and defensive positions or instead, they will be specialists who play a key role on special teams.

When the offence is playing, they are trying to advance the ball down the field in an attempt to score points by reaching the end zone. The defence are trying to stop exactly that and force the offence to turnover the ball by either stealing possession of the ball during a play, or forcing them to give up possession when they have their progress halted.

Timings

All football games are divided into four quarters. There are small breaks between quarters 1 & 2 and quarters 3 & 4, with a much longer break at half time between quarters 2 & 3. Each quarter in the NFL and College is 15 minutes long, while High School quarters are just 12 minutes.

Although the quarters are 15 minutes in length, the actual run-time of a given quarter can be much longer. This is because the clock is stopped for various events during the game. You'll see clock stoppages for timeouts, penalties, injuries, after certain plays and at the end of quarters/halves. This is done to ensure that the time recorded by the clock is actual time playing football. All the stoppages would take up too much of the time in each quarter and lead to barely any football played.

These stoppages mean that an NFL game can have 60 minutes of play time but can actually last 3 hours from kick-off to the final whistle.

Scoring

The objective of football is to score more points than your opponent by the time the clock hits zero. There are four different ways a team can score:

Touchdown: Six Points - This happens when a player runs in or catches the ball in the opposition's end zone.
Extra Points: One or Two Points - When the team scores a touchdown, they have the opportunity to score extra points afterwards. They can either kick the ball between the upright posts for one point or attempt to reach the end-zone again for two points. By rule, two-point conversions are always attempted from the 2 yard line.
Field Goal: Three Points - A field goal is attempted when one team's offence can't reach the end zone but they are close enough to attempt to kick the ball through the upright posts at the end of the field. This is worth three points.
Safety: Two Points - A safety occurs when an offensive player is tackled in their own end zone (behind the goal line) while in possession of the ball. This is worth two points for the team one defence.

Downs System

Each offensive drive is guided by a system of downs.

The offence has four attempts (downs) to move the ball 10 yards from their starting point. Each time they achieve a 10 yard gain, the downs are reset and the team is awarded another four downs with another 10 yard gain required for another reset of downs. Each down is played from the line of scrimmage which is the starting point for the offence on that attempt.

The 10 yards the offence needs to achieve is marked from their first-down starting point. This is why you will see "1st & 10" at each reset of downs. As they move closer to the 10-yard mark the distance they need to travel is reduced as a result. This is why you may see something like "2nd & 6" on the screen if the team travels 4 yards on first down, and "3rd & 1" if they travel another 5 yards on 2nd down, and so on...

If a team gets to fourth down they can still attempt to reach the first down mark, but if they fail to do so, the opposing offence will take over possession of the ball at the exact point it was lost. Instead, the team may choose to punt the ball on fourth down, in order to pin the opposition deep in their own half.

The down is signalled by a "chain crew" on the sideline. They carry two posts that have the down number listed on top, the posts are connected by a 10-yard chain which is used to measure the distance the offence needs to travel for a first down.

Teams & Player Roles

For each team, there are 11 players on the field at any given time, but unlike most other sports there's more than just the offence and defence. American football teams have three separate units: offensive teams, defence teams and special teams.

Offence

The offence is the unit that takes possession of the ball in an attempt to travel the length of the field and score. Arguably the most important football position of all and certainly the most vital to the offence, is the quarterback (QB).

The quarterback is responsible for controlling the offence on every single play, as per the play calls of the offensive coordinator. The quarterback will receive the play call from coaches and coordinators on his sideline, then relay the call to the rest of the unit and execute the play accordingly. The ball will touch the quarterback's hands almost every play of the game, so they are hugely important in achieving offensive success.

The offence will try to progress down the field by either throwing the ball to wide receivers (WR), running backs (RB) or tight ends (TE), or running the ball, mostly with the running back.

The offensive line is also crucial to achieving first downs. It consists of five players: the centre (C), left guard (LG), right guard (RG), left tackle (LT) and right tackle (RT).

The entire line is responsible for blocking defensive players attempting to reach the ball-carrier or the quarterback before he can throw. The centre will hold the ball on the floor at the line of scrimmage and 'snap' the ball (pitch it backwards between his legs) to the quarterback which signals the start of the play.

Defence

The defence's goal is simply to stop the ball being moved down the field by the opposing offence and minimise the amount of points scored. They achieve this in a variety of ways:

Sacking the QB: This is when a defensive player tackles the quarterback behind the line of scrimmage while they are in possession of the ball.
Tackling the ball-carrier: Whether it is a run or pass play, the defence can tackle the player with the ball in an attempt to limit the amount of yards gained and ideally prevent a first down.
Creating turnovers: A turnover is achieved when the defence takes possession of the ball during a play. They can either intercept a pass or force a player to fumble (drop) the ball and take it into their own possession.

There are various positions on the defence.

The defensive backs are the cornerbacks (CB), free safeties (FS) and strong safeties (SS). These players are mostly responsible for covering the receivers and breaking up pass attempts, though they will also assist in stopping the run.

The defensive line consists of defensive tackles (DT), nose tackles (NT) and defensive ends (DE) who are most often attempting to reach the quarterback before they can attempt a pass, but also try to tackle the running back before they can gain yards.

The linebackers (LB) stand behind the defensive line and are the most versatile defensive players as they are heavily involved in pass coverage and stopping the run.

Special Teams

Special teams consists of various units, but the main two are Punt and Kick-off. Both sides of the ball in these plays are considered special teams units: with punt, punt return, kick off and kick return teams all included in the umbrella term.

Kick off:

Kick offs occur at the start of the game, at the start of the second half and after a field goal or touchdown is scored.

The team that takes the opening kick off is chosen by a coin flip, while the team that kicks off after a scoring play is the team that scored - giving possession over to the team that conceded.

On the kicking team, there is the kicker and 10 other players who are attempting to reach the kick-returner and tackle them as soon as possible. On the returning team, there is similarly a returning player who catches the ball and attempts to return it as far as possible, while the other 10 players block as many of the kicking team as they can.

Punting:

This is when a specialist kicker will come onto the field and kick the ball to the opposing team, who will have a player waiting to receive it and run it as far back into their opponents territory as possible. The kicker will be trying to pin the opposition as close to their end zone as possible, as this will give their offence the most distance to travel in order to score.

Penalties

Penalty rulings vary from league to league, but for now we’ll stick to the NFL.

Here are a few key points:

When a penalty is seen by an official, whether it's a dead-ball foul or during a play, they will throw a yellow flag at the point they witness it. This is a signal to both teams that a penalty has been called.
Every penalty call will stop the clock at the next dead-ball moment.
Every penalty will be reviewed by officials to check if the call made with the naked-eye was accurate.
When a penalty is confirmed, the official will state the call and the player involved, joined by a series of signals that are unique to each penalty.

There are roughly 80-100 distinct penalties in the NFL, so running through the rules of every single one would take hours if not days.

To check out the full list of penalties - click here.