A team is made up out of 15 players eight forwards numbered 1 to 8, and seven backs, numbered 9 to 15. Depending upon thecompetition, there may be up to 7 replacements. Each player has a fixed role. By definition, the teams will therefore play thesame formation, with only slight variations in use. Rugby therefore is different to for instance soccer with its endless number of 'playing systems' (4-3-3, 3-5-2 etc.) orcricket, where a player may be moved to a completely different position on the field (e.g. from silly mid-on todeep cover point).
A player's tasks are made clear by the number he wears, as this indicates his position (unless he's a substitute or hasswitched position during the match). This means a player does not get a personal number for his entire career, as you tend to seein most American sports. The IRB has laid down a numbering scheme for international matches, which is commonly adopted by otherteams as well.
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 theline-out. Generally, forwards are larger than the backs, which makes them stronger but slower. Forwards also havea role in taking the ball forwards, but generally do so by driving into the opposing forwards.
The role of the backs is to move the game forward by running or kicking the ball. The fly-half controls how to do this. Thebacks tend to score more tries. The backs tend to be smaller than the forwards and as a result more agile and faster, but lessstrong.
The following diagram locates the various positions in the 15-man team. All members of the starting 15 wear jerseys numberedfrom 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.
| Loosehead Prop (1) | Hooker (2) | Tighthead Prop (3) | |||
| Lock (4) | Lock (5) | ||||
| Blindside Flanker (6) | Number 8 | Openside Flanker (7) | |||
| Scrum Half (9) | |||||
| Fly Half (10) | |||||
| Inside Centre (12) | |||||
| Left Wing (11) | Outside Centre (13) | ||||
| Right Wing (14) | |||||
| Fullback (15) |
Alternate names for positions include:
| Front row | Collective term for the props and hooker |
| Second row or Lock Forward | Lock |
| Tight forwards or Tight 5 or Front five | Collective terms for the combined front row and second row |
| Flanker | Wing Forward or Breakaway or Flank or Flank Forward |
| Number 8 | Eightman or Eighthman |
| Loose forwards or Back row or Loosies | Collective terms for the flankers and Number 8 |
| Scrumhalf | Halfback |
| Flyhalf | Outside Half or Out half or Stand-off or First Five-Eighth or or First Five or Halfback |
| Inside centre | Second Five-Eighth or Second Five |
| Outside centre | Centre |
| Midfield | Centres plus Flyhalf |
| Inside backs | Collective term for the Centres, the Flyhalf and the Scrumhalf |
| Three-quarters | Wingers plus Outside Centre (some nations include Inside Centre) |
| Back three or Outside backs | Collective terms for the fullback and wings |
The Fly-Half is alternatively called the "Stand-Off Half", since he is the half-back which stands off from the scrum ratherthan close to it. In addition, in New Zealand the Fly-Half is referred to as the 1st 5/8, implying a slightly deeper positionthan 1/2 back and the Inside Centre as the 2nd 5/8 implying a more forward position than 3/4 back. Flankers may also, though thisis more historic usage, be referred to as "wing-forwards", or together with the No 8 as "loose-forwards", since they can quicklydetach from scrums.
In Australia, the second row of the scrum are often referred to as "secondrow", the position behind them as "lock", the forwards on either side of the lock as "breakaways", and the fly-half as"five-eighth".
As can be seen there is a lot of variation in the names of the positions. The IRB has standardized the names, yet thealternative names are still as common as ever before. A problem with standardized names is that the positions themselves are notas standard as they might seem. For example, there is a slight difference between left and right centre on the one hand andinside and outside centre on the other. Wingers can be played on the open side and the blind side (also known as strong side andweak side) rather than left and right and you may come across left and right flankers.