Rugby football is the collective name for the team sports of rugby union or rugby league.

Rugby football started at Rugby School in Rugby, Warwickshire, England,^[1] where the rules were first codified in 1845.^[2] Forms of football in which the ball was carried and tossed date to the Middle Ages (see medieval football).^[3] Rugby football spread to other English public schools in the 19th century and across the British Empire as former pupils continued to play it.

Rugby football split into two codes in 1895, when twenty-one clubs from the North of England left the Rugby Football Union to form the Northern Rugby Football Union (renamed the Rugby Football League in 1922) at the George Hotel, Huddersfield, over payments to players who took time off work to play ("broken-time payments"), thus making rugby league the first code to turn professional and pay players.^[4] Rugby union turned professional one hundred years later, following the 1995 Rugby World Cup in South Africa.^[5][6] The respective world governing bodies are World Rugby (rugby union) and the International Rugby League (rugby league).^[7]

Canadian football and, to a lesser extent, American football were once considered forms of rugby football, but are seldom now referred to as such. The governing body of Canadian football, Football Canada, was known as the Canadian Rugby Union as late as 1967, more than fifty years after the sport parted ways with rugby rules.^[8][9][10]

Following the 1895 split in rugby football, the two forms rugby league and rugby union differed in administration only. Soon the rules of rugby league were modified e.g. removing the line-out and replacing the ruck with the play-the-ball, resulting in two distinctly different forms of rugby.

The Olympic form of rugby is known as rugby sevens (based on rugby union format). In this form of the game, each team has seven players on the field at one time playing seven-minute halves. The rules and pitch size are the same as rugby union.^[11]

Distinctive features common to both rugby codes include the use of an oval ball and the prohibition of the forward pass. Due to the prohibition, players can gain ground only by running with the ball or by kicking it. Furthermore, unlike American and Canadian football, neither league nor union players wear any sort of protection or armour.

The two rugby codes differ as the result of changes made to the rules of rugby league. League implemented these changes with the aim of making a faster-paced and more try-oriented game than rugby union.

The main differences between the two games, besides league having teams of 13 players and union of 15, involve the tackle and its aftermath:

• Union players contest possession following the tackle: depending on the situation, either a ruck or a maul can occur. League players may not contest possession after making a tackle: play is continued with a play-the-ball.
• In league, if the team in possession fails to score before a set of six tackles, it surrenders possession. Union has no six-tackle rule; a team can keep the ball for an unlimited number of tackles before scoring as long as it maintains possession and does not commit an offence.

Set pieces of the union code include the scrum and the line-out. The scrum occurs after a minor infringement of the rules (most often a knock-on, when a player knocks the ball forward). After an infringement, packs of opposing players "scrum" or push against each other for possession. In a line-out, parallel lines of players from each team, arranged perpendicular to the touch-line, attempt to catch the ball thrown from touch. A rule has been added to line-outs which allows the jumper to be pulled down once a players' feet are on the ground.

In the league code, the scrum still exists albeit with greatly reduced importance. In league, the scrum involves fewer players and is rarely contested. Set pieces are generally started from the play-the-ball situation.

Many of the rugby league positions have names and requirements similar to rugby union positions. Notably, however, there are no flankers in rugby league.

About a quarter of rugby players are injured in each season.^[32]

Being a high contact sport, rugby union has the highest announced rates of concussions^[33] and outside England also has the highest number of catastrophic injuries^[34] out of any team sport.^[35][36] Research finding that during match play,^{[weasel words]} concussion was reported at a higher level, and during training at a lower level, but still at a higher level than most players of another sport to receive.^[36]

A rugby ball is a diamond shape ball used for easier passing. Richard Lindon and Bernardo Solano started making balls for Rugby school out of hand stitched, four-panel, leather casings and pigs' bladders. The rugby ball's distinctive shape is supposedly due to the pig's bladder, although early balls were more plum-shaped than oval. The balls varied in size in the beginning depending upon how large the pig's bladder was.

In rugby union, World Rugby regulates the size and shape of the ball under Law 2 (also known as Law E.R.B); an official rugby union ball is oval and made of four panels, has a length in-line of 280–300 millimetres, a circumference (end to end) of 740–770 millimetres, and a circumference (in width) of 580–620 millimetres. It is made of leather or suitable synthetic material and may be treated to make it water resistant and easier to grip. The rugby ball may not weigh more than 460 grams or less than 410 and has an air pressure of 65.71–68.75 kilopascals, or 0.67–0.70 kilograms per square centimetre, or 9.5–10.0 lbs per square inch.^[37] Spare balls are allowed under the condition that players or teams do not seek an advantage by changing the ball. Smaller sized balls may also be used in games between younger players. Much larger versions of traditional balls are also available for purchase, but these are mainly for their novelty attraction.

The Rugby League World Cup was the first World Cup of either of the Rugby codes and was first held in France in 1954, and as of 2013 occurs on a 4-year cycle. It is an international tournament that is organized by the Rugby League International Federation. The event is played in the league format and features the top 16 teams from around the world. Australia won the 2017 Rugby League World Cup, played in Australia, New Zealand and Papua New Guinea. The Kangaroos backed this up by winning the 2021 tournament also.

The Rugby World Cup, which was first held in New Zealand and Australia in 1987, occurs every four years. It is an international tournament organized by World Rugby. The event is played in the union format and features the top 20 teams from around the world. South Africa won the 2019 Rugby World Cup, which was played in Japan. Since 2013, the two World Cups alternate every two years during the four-year period.

Rugby shirts were formerly entirely made of cotton but are now made of synthetic fabric. This material has the advantage of not absorbing as much water or mud as cotton.^[38] Owing to the more aggressive nature of the game, rugby clothing, in general, is designed to be much more robust and hardwearing than that worn for association football.

The rugby jerseys are slightly different depending on the type of rugby game played. The shirts worn by rugby league footballers commonly have a large "V" around the neck. The players in rugby union wear jerseys with a more traditional design, sometimes completely white (Cahors Rugby in France). The number of the player and his or her surname are placed on the upper back of the jersey (often name above number, with the number being significantly larger and more central), and the logo of the team on the upper left chest.^{[citation needed]}

With the popularity of rugby over the years, many betting establishments have made it possible for viewers of the game to place wagers on games. The various types of wagers that can be placed on games vary, however, the main types of bets that can be placed are as follows:

• Fixed-odds betting
• Futures/Outright Bets
• Prop Bets / Specials
• Over/Under Bets

Like most team sports, both forms of rugby are vulnerable to match-fixing, particularly bets involving easily manipulated outcomes such as conceding penalties and first point scorer. A recent example is a deliberate infringement by Ryan Tandy in order for the first points scored to be a penalty goal in a 2010 NRL match; the attempt backfired when instead of taking a shot at goal, a try was scored.

• College rugby