A rugby team is made up of 15 players: eight forwards, numbered from 1 to 8; and seven backs, numbered from 9 to 15. Depending upon the competition, there may be up to seven replacements.
Each player has a fixed role with specialist positional skills and each team uses the same formation, with only minor variations.
Individual players' positions are made clear by the number they wear, as this generally indicates their role on the pitch (unless they are a substitute or have switched position during the match). This means a player does not get a personal squad number for his entire career, as in most American sports or in football. The International Rugby Board (IRB) has laid down a numbering scheme for international matches, which is adopted at almost all levels of the sport.
The main role of the forwards is to gain and retain possession of the ball. They take part in set pieces of the scrum and the line-out. Generally, forwards are larger than the backs, and were traditionally stronger but slower and less agile. However, the modern game has seen a change in the athleticism of forwards - many are now just as fast and adept in open play as their counterparts in the backs. Forwards also have a role in ball carrying, but generally do so by driving into the opposing forwards. The Laws of the Game define the terms prop, hooker, locks, flankers and number eights and clearly state that a 3-2-3 or 3-4-1 formation must be used at scrums.
The role of the backs is to take the ball won by the forwards and score points, either by running or kicking the ball. They are usually more agile and faster than forwards, but not as strong. The key attribute for most positions in the back line is pace - however, the various specialist positions also require different skills, for example, the kicking abilities needed by a good fly-half or fullback. Again, the type of person who would traditionally play in the backs - small, agile, fast - is changing, with the advent of professionalism bringing increased size and strength into the backs.
The following diagram locates the various positions in the 15-man team. All members of the starting 15 wear shirts numbered from 1 to 15 and keyed to their positions (though alternatives exist); these numbers appear on the diagram below. The first eight players, known as forwards or the pack, play in the scrum. The remaining seven players play as the backs.
Positions and Explanation
Number 15 Full back
The full back stands back to cover defensive options as a 'sweeper' behind the main line of defence removed from the other backs principally to field any opposition kicks. As the last line of defence, good tackling skills are desirable.
Backs have to catch the high kicks referred to as "up and unders", "Garryowens" or "bombs". Having taken a catch, the full back may choose to return the kick, and so good tactical awareness and kicking skills are required. Increasingly often, full backs are used to start counter-attacking moves from depth. Thus, they need to have excellent attacking skills, pace and open field running prowess. In attack, the full back generally joins the three-quarter line between the outside centre and the openside wing, providing the attacking team with an extra outside back.
Number 14 and 11 Wings
The wings act as "finishers" on movements by scoring tries. The idea is that space should be created by the forwards and backs inside the wingers so that once they receive the ball, they have a clear run for the try-line. Wings are almost always the quickest members of the team, but also need to be able to side step and otherwise avoid opponents in order to score tries. In modern games, wingers often "come off the wing" to provide extra men in the midfield, in the same vein as a full back, particularly if play has moved away from their wing. Traditionally, wingers are small and fast but since the game became professional, wingers are often as big as forwards. Wingers of this variety are often used as extra flankers to gain the "hard yards" by carrying the ball directly into contact with opponents, gaining ground slowly through phased play.
Wingers often act as additional full backs on opposition kicks. In addition to this responsibility, they must get back from an opposition kick to give the full back options on either side. The modern game means that the back three tend to act as a unit in fielding kicks and counterattacking, rather than all responsibility lying with the full back. Wingers need to have all the skills of a full back, though the emphasis would be on attack rather than defence. As such, many players are as competent on the wing as at full back.
A common tactic is to have the winger receive the ball and then cut towards the centre of the pitch. This changes the direction of play, which may catch the opposition off guard, or may create space for the outside centre to receive a switch pass or "scissors pass".
Number 12 and 13 Centers
Centers need to have a strong all-round game: they need to be able to break through opposition lines and pass the ball accurately. When attack turns into defence they need to be strong in the tackle. Usually the two centers are divided into outside center and inside center, though sometimes teams play with left and right centers.
The inside center has recently seen a development in its role. Now, they share many qualities of the fly-half, for example, kicking and distribution. They must also be a very good tackler, and usually lead a rush defence if it is called.
A good center will be one of the most versatile players in the game: it is easy to switch from there to the wing, fullback, or fly-half. They vary in physique, which usually affects their game plan. A big center will be used for crash balls or switches, whereas a smaller center may change his game to become a more fly-half related center. The outside center also sees two roles. They are the "rapiers" that are given the ball, normally via the fly-half or inside center, to make breaks through the opposition backs before offloading to the wingers after drawing the last line of defence. The first type of outside center is the attacking one. This type makes them faster and very agile, almost like a winger. The second is the defensive, who draw attention away from the wingers to try and give them space. A good mix of the two is what most teams look for.
Number 10 Fly-Half
A fly-half is crucial to a team's game plan. They are usually the one who calls set moves, or makes tactical decisions. They need to be quick-thinking in a game; such as the speed at which a situation is deteriorated, they need to be able to communicate with all their backs and adapt them to the attacking or defending situation. Usually, the fly-half is the kicker of the team, a role often shared with the centres or fullback. A lot of fly-halves are goal kickers, and make most kicks for the team, whether it's tactical, or for touch.
Number 9 Scrum-Half
Scrum halves form the all-important link between the forwards and the backs, and are invariably at the centre of the action. A scrum half is normally relatively small but with a high degree of vision, the ability to react to situations very quickly, and good handling skills, as well as the ability to spin the ball with great ease off both hands.
They are often the first tackler in defence and are behind every scrum, maul or ruck to get the ball out and maintain movement. They put the ball into the scrum and collect it afterwards; they also are allowed to stand further forward than other backs at a line-out to try to catch knock downs from the jumper.
It is also not unusual to have talkative scrum-halves in competitive situations.In some cases, though technically illegal, most scrum-halves will subtly alert the referee to fouls and infringements committed by the opposing team.
Number 1 and 3 Props
The role of both the loose- and tighthead props is to support the hooker in the scrum and to provide effective, dynamic support for the jumpers in the line-out. Along with the second row, the props provide the main power in the push forward in the scrum. For this reason they are usually the strongest and heaviest players in the team. Under modern rules non-specialists are not allowed to play as props (or hooker) as specialist skills are required to ensure the scrum does not collapse, a situation which can be very dangerous sometimes resulting in crushing or breaking of the neck and spine. If there are not enough props or hookers on either team (and no replacements are available), uncontested scrums will be set, where no pushing is permitted, and the team putting the ball into the scrum has to win it.
A tighthead prop is so called because they pack down on the right-hand side of the scrum and so (because the players engage to the left of their opponents) their head fits between the opposing loosehead prop and hooker. In contrast, the loosehead prop packs down on the left-hand side where their head is outside that of the opposing tighthead prop. Although it may look to the neutral observer that the two positions are quite similar (and some players have the ability to play on both sides of the scrum), the technical challenges of each are quite different.
The laws of the game require the tighthead prop to bind with his/her right arm outside the left upper arm of his/her opposing loosehead prop and similarly they restrict what the loosehead prop can do with his/her left arm. Hence, the laws implicitly require the loosehead prop to be on the left side of the scrum. Although the scrum half may put the ball in on either side of the scrum, they are unlikely to choose the tighthead side because otherwise the opposing hooker would be between him and his hooker.
Props are also in the position of being able to direct the movement of the scrum in moving side to side to prevent the other team's scrum from "wheeling" the set scrum and forcing another "put in" from the opposing side.
Outside of the scrum and line-outs, props use their great strength and weight to win rucks and mauls for their teams and to make large drives forwards with the ball.
Number 2 Hooker
Hookers are a key position in attacking and defensive play. The name is derived from the fact that hookers use their feet to 'hook' the ball in the scrum; because of the pressure put on the body by the scrum it is considered to be one of the most dangerous positions to play. They also normally throw the ball in at line-outs. Hookers have more in common with back row forwards, with many being used as ball carriers, despite the fact that they are often the smallest of the forwards. The hooker is typically a key player in the scrum generally being regarded as its leader. A hooker will not allow his forwards to engage until he feels that the binds are right and all players are ready. In addition, hookers may act as an extra prop in the scrum and, instead of contesting the feed, they aim to wreak havoc on opposition feeds. Often the hooker and the loosehead prop will combine to attack the opposition tighthead, as disrupting the no. 3 is often the key to gaining the upper hand at scrum time. Hookers tend to control the forwards and are often the players who direct the forwards in mauls.
Number 4 and 5 Locks
Locks are almost always the tallest players on the team and so are the primary targets at line-outs. At line-outs, locks must jump aggressively, usually being lifted by team-mates, to catch the ball and get it to the scrum half or at least get the first touch so that the ball comes down on their side.
The two locks stick their heads between the two props and the hooker in the scrums. They are also responsible for keeping the scrum square and the front row together and providing power to shift it forward. (This position is referred to as the "engine room".)
Locks are very tall, athletic and have an excellent standing jump along with good strength. They also make good ball carriers, bashing holes in the defence around the ruck and maul. They also have to push the rucks and mauls and are the main figures of rucks and mauls.
Number 6 and 7 Flankers
Flanker is a fairly dynamic position with the fewest set responsibilities during the game. It is their responsibility to clear up messy balls to start a new phase of play, meaning they play a major role in maintaining/gaining possession after handling errors.
In the scrum, flankers do less pushing than the tight five, but they have to break away quickly and attempt to tackle the opposing backs if the opposition wins the scrum; and to cover their own half backs if they win the scrum. Due to their role in the scrum, flankers should be fairly heavy whilst still having speed and power. The blindside should be the bigger, more destructive defensive player whilst the openside should be the quicker of the two, who along with the scrum half and the number eight, offers a good quick link to the backs.
Considering how dynamic this position is, flankers can adapt slightly to their own style of play; for example, they can become big figures in tackling and mauls, or use their pace to run with the backs for tactical manoeuvres and get through the opposition's defense.
Number 8 Eight Man
Number eight is the only position that does not have a specific name in English and is simply referred to as "number eight" or "eighthman". The modern number eight has the physical strength of a tight forward along with the mobility and pace of other loose forwards (he is often the fastest loose forward in the pack). The number eight packs down at the rear of the scrum, controlling the movement of the ball to the scrum-half with his feet. The number eight is the position where the ball enters the backline from the scrum and, hence, both fly-half and inside centre take their lead from the number eight who, as the hindmost player in the scrum, can elect to pick and run with the ball like a back. As a result, the number eight has similar opportunities to a back to run from set plays.
They are normally tall and athletic and used as an option to win the ball from the back of the lineout. Like flankers they do less of the pushing than locks or props, but need to be quick to cover opposition half-backs. A number eight should be a key ball-winner in broken play, and occasionally a 'battering ram' at the front of rucks; he should also be able to break the opposition's line like his blindside flanker counterpart and the centers.