A comparison between American football and rugby league is possible because of their shared origins and similar game concepts. Rugby league is arguably the most similar sport to American football after Canadian football: both sports involve the concept of a limited number of downs/tackles and scoring touchdowns/tries takes clear precedence over goal-kicking.
Generally, American football games last much longer than 80-minute rugby league matches. Because the field is reset after each tackle in American football, it is much slower-paced than the more hectic rugby league, in which play stops for only as long as it takes the tackled player to get back to his feet and return the ball to play. Another major difference is that only the player with possession of the ball may be interfered with in rugby league; defending players interfering with any other attacking player (and vice versa) will incur a penalty. Passing in the two sports also differs: while backward passing is common to both sports, in American football players are allowed to throw the ball forward in certain situations whereas in rugby league forward passing is always illegal. Rugby league footballers have to kick the ball or run it forward to advance it downfield. To score a try or touchdown in rugby league, the player has to push the ball directly onto the ground once in the try zone, whereas in American football the player has to simply have possession of the ball as it crosses the plane of the goal-line, or receive a forward pass while in the end zone.
American football requires its players to use a large amount of protective equipment, including helmets, gloves and padding around the body, whereas protective clothing is much more minimal in rugby league, usually amounting to light padding (if any) and soft headgear (hard helmets being illegal). The playing fields of both sports are similar in size with a rugby league playing field being long while an American football field is long.
Origins Both sports descend from the older game of rugby football, which originated in 19th Century England. British colonists and the British military in Canada brought football to North America. It became popular in American and Canadian universities and prep schools. At the time, association football and rugby football were not as differentiated as they are now and teams would negotiate the rules before playing each game. The sports of American football and Canadian football evolved from these intercollegiate games.
Meanwhile, in England a schism developed in rugby football between those who favoured strict amateurism and those who felt that players should be compensated for time taken off work to play rugby. In 1895, this resulted in the formation of a break-away sport, rugby league, which permitted player payments. At first, the two rugby codes differed only in how they were administered; over time, their playing rules diverged to the point that they are now distinctly different forms of football.
The field
American football is played on a rectangular field long by 53 1⁄3 yards (48.8 m) wide. Near each end of the field is a goal line, which are apart. A scoring area called an end zone extends beyond each goal line. Yard lines cross the field every , two rows of hash marks run parallel to the side lines near the middle of the field. At the back of each of the end zones, there are a set of goalposts. American football goalposts were formerly H-shaped and were located on the goal line, but; in 1967, the NFL adopted the current modern offset-fork design, made from extruded steel pipes. The goalposts currently consist of two vertical posts 18.5 feet (5.6 m) apart (24 feet (7.3 m) in high school football) rising from a horizontal crossbar, which is mounted on a single central support post that raises the crossbar to a height of 10 feet (3.0 m), resulting in a two-tined fork shape. The central vertical post is offset from the crossbar toward the rear, placing it as far as possible from the field of play; it is also usually padded to minimize collision-related injuries. In 1974, in the effort to create a safer, unimpeded field of play in the end zone, calculated to produce more passing touchdowns, the NFL relocated the goalposts from the goal line to the end line.
A rugby league field has very similar dimensions, being up to long and wide. Lines cross the field marking every . The goal posts are situated on the goal line and are therefore separated by exactly . The area beyond each goal post, known as the in-goal area, extends for another . In rugby league, the goal posts are usually H-shaped, each post being high and apart, with the cross bar being high. American football "tuning fork" goal posts are allowed in rugby league, provided the posts and cross bar are at the required dimensions.Rugby League Laws , p. 3 The goal posts are used for other forms of point scoring in rugby league: drop goals or field goals, penalty goals and conversions.
Players
As four replacements in a rugby league team, with only twelve interchanges of players allowed to be made throughout the game (eight in the Australian NRL). If the interchanges are used up and a player becomes injured and cannot continue, the team simply has to play short handed. All players must attack and defend and there is no equivalent of special teams.
Prior to the 1960s, and in arena football (an indoor variant of the American game) from 1988 to 2007, American football did use a one-platoon system in which most players were required to play all facets of the game, severely limiting substitution, much as rugby league (and most other sports) continue to do. Most levels of American football abolished the one-platoon system in the late 1940s and early 1950s, although college football re-implemented it for a short time in the 1950s and 1960s.
Broadly speaking, offensive and defensive linemen in American football correspond to forwards in rugby league and other players are somewhat similar to backs. Basically the job of the forwards in rugby league is to get the ball over the advantage line and give the backs space and a chance to be creative and move the ball around, which will hopefully result in points. However, rugby league footballers are far less specialised than American football players.
Many of the positions have similar names but in practice are very different. A fullback in American football is very different from a fullback in rugby league. However, some of the positions are fairly similar: for instance, the stand-off/five-eighth and halfback carry out a similar role to a quarterback in American football.
Advancing the ball In American football, the team that's in possession of the ball (the offense) has four "downs", to advance the ball 10 yards towards the end zone. When the offense gains 10 yards, it gets another set of four downs. If the offense fails to gain 10 yards after 4 downs, it loses possession of the ball.
A down ends, and the ball becomes dead, after any of the following: The player with the ball is tackled. A forward pass goes out of bounds or touches the ground before it is caught. This is known as an incomplete pass. The ball is returned to the original "line of scrimmage" for the next down. The ball or the player with the ball goes out of bounds. The player either goes or is forced out of the field (out of bounds) The offense turns the ball over to the defense. A team scores.
This closely resembles the six-tackle rule in rugby league. Originally, tackles were unlimited in rugby league, as they are in the related sport of rugby union. As this could result in long periods with one team in possession of the ball, in 1966 the game's administrators implemented the limited tackle rule from American football. At first, the number of tackles was set at four, as in American football; it was later extended to six to give teams more time to develop attacking play. After six tackles, the team with the ball has to hand over possession to the opposing team. A key difference with American football is that there is no automatic way of earning a new set of tackles in rugby league. Each set is effectively a chance to score, with failure to do so resulting in relinquishing possession. Another major difference is that play stops briefly when the player in possession of the ball is tackled as it resumes as soon as he gets to his feet and returns the ball to play.
Players can advance the ball in two ways in American football: By running with the ball, also known as rushing. One ball-carrier can hand the ball to another; this is known as a handoff. By passing the ball forwards to a teammate. This can only be performed once on a down, and cannot be attempted after the ball crosses the line of scrimmage. The illegal forward pass rule has changed several times, with the current NFL rule being that the passer's entire person must be beyond the line of scrimmage for a forward pass to be illegal. The passer (most often the quarterback but not always so) can therefore straddle the line of scrimmage, or even be mostly beyond it, but still legally pass the ball, regardless of where the ball is in relation to the line of scrimmage.
In rugby league the ball cannot be passed forward, so players can advance the ball by either running with it, or kicking it ahead and chasing it. This concept is preserved in American football; any player may pass the ball backwards, regardless of player position and location of the field. In addition, a ball passed backwards remains live, even if not caught, so long as it remains in play, similar to rugby league.
Following a down, the ball is returned to play within a restricted time limit by a "snap" in American Football. All players line up facing each other at the line of scrimmage. One offensive player, the center, then passes (or "snaps") the ball back between his legs to a teammate, usually the quarterback and play commences.
In rugby league the ball is returned to play following a tackle via the "play the ball", in which the tackled player gets back to his feet and rolls the ball back to a teammate, usually the hooker. The tackled player will usually try to return to the ball to play as quickly as possible before the defensive line can re-form.
Possession may change in different ways in both games:-
An automatic handover takes place when the team in possession runs out of downs / tackles. When the ball is kicked to the opposing team. This can be done at any time but it is normal to punt on the last down / tackle. Following an unsuccessful kick at goal. When an opposing player intercepts a pass. In rugby league the opposition are awarded a scrum if the player in possession drops the ball forwards or makes the ball go forwards with any part of his body other than his feet. This is called a knock-on. When the player in possession drops the ball and it is recovered by an opposition player. This is called a fumble in American football and a knock-on in rugby league. In rugby league if the ball goes out of play, the opposition are awarded a scrum the "loose head and feed" of the scrum. Penalties and 40/20 kicks are exceptions to this rule. In American football possession changes hands following a successful score and the team scoring kicks off to the opposition. In contrast, in rugby league the team who conceded the points must kick off to the team who scored. (In some amateur levels of American football, and in Canadian football, the team who conceded the points has the option of kicking off to the opposition rather than receiving the kickoff, but this option is extremely rarely invoked.)