Various forms of football have been played in England for centuries with different villages and schools having their own traditional rules. The first set of Rugby school rules were published in 1845.
The formation of the Football Association were formed in October 1863 each football team would agree on a set of rules with opponents before a match. Differences of opinion about the rules led to the formation of the first governing body for rugby in 1871 the Rugby Football Union.
British colonists and the British military in Canada brought rugby to North America. It along with association football became popular in American and Canadian universities. At the time soccer and rugby were not as differentiated as they are now and teams would negotiate the rules before playing a game. The sport of American football evolved from these intercollegiate games (see History of American football).
The Football Association was the governing body for football in England but A schism developed 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, the rules of the two codes of rugby union and league would themselves diverge.
A try is the rugby equivalent of a touchdown. Unlike American football, both codes of rugby require the ball to be grounded, in American football it is sufficient for the player carrying the ball to enter the end zone (in-goal area). In American football a touchdown scores 6 points; in rugby union it is worth 5 points.
In both games, following a try / touchdown, there is the opportunity to score additional points by kicking the ball between the posts and over the bar. In American football this is called an extra point (worth 1 point); in rugby union it is known as a conversion (worth 2 points). One key difference between an extra point and a conversion is that a conversion must be taken from a position in line with where the try was scored. Hence it is important to ground the ball under the posts rather than in the corner which makes for a difficult kick.
In American football teams often opt to go for a field goal (worth 3 points) rather than attempt a touchdown. The rugby equivalent is a drop goal (worth 3 points in union and only one in league). The key difference between a field goal and a drop goal is that a field goal attempt is normally kicked with a team-mate holding the ball, whereas in rugby the ball must hit the ground and be kicked from a half-volley.
A similar concept in rugby is the penalty goal. Following the award of the penalty, the attacking team may opt to kick for goal rather than advance the ball by hand or punting. This scores 3 points. The penalty goal is similar to a field goal in American football in that the ball is kicked from the ground and may be held by a team-mate, but it cannot be charged. There is no direct equivalent to a penalty goal in American football.
American football has one further method of scoring which does not exist in rugby. If a ball carrier is tackled in their own endzone (in-goal area) with the ball then this results in a safety which scores 2 points. In rugby union this does not score any points but causes the team in possession to kick the ball back to the opposition from their 22 metre line.
In American football, one team retains possession, unless there is a fumble or interception, until they have used up all four downs.
Rugby union is quite different being based on the 'right to contest possession'. A team in possession does not need to surrender possession whilst they are able to keep the ball. Whilst American footballers aren't allowed to try to disposses the ball carrier between tackles, rugby union players are allowed to win possession during open play.
In both codes, it is normal to advance the ball by carrying it in hand but tactical kicking is an important aspect of play. In American football, it is normal to punt on the last down but in rugby union with no limited tackle system a kick can take place at any phase of play.
In rugby, forward passes are not allowed and the only form of passing is what would be called a lateral in American football. Only one pass per down may be thrown forwards in American football but any number of laterals may be thrown, in practice laterals are fairly unusual in American football.
An American football team consists of an offensive team, a defensive team and a special team (involved in kicking). Only eleven players can be on the field at any time.
In both kinds of rugby the same players have to both defend and attack. There are fifteen players in a rugby union team (except in sevens). Interchange players can come onto and off the field as long as this maximum number of players is not exceeded.
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. Some of the positions are fairly similar; a fly-half carries out a similar role to a quarterback in American football.
Broadly speaking linemen and linebackers in American football correspond to forwards in rugby, and running backs, receivers, and quarterbacks have skills similar to backs in rugby.[1]