Rugby union positions start with the numbers.

The basic 15-player layout

Rugby union divides the team into forwards and backs. The forwards contest the tight set pieces and much of the close-contact work. The backs usually have more space to pass, kick, chase, defend wide channels, and finish attacks.

• Forwards: 1 loosehead prop, 2 hooker, 3 tighthead prop, 4 and 5 locks, 6 and 7 flankers, 8 number eight.
• Backs: 9 scrum-half, 10 fly-half, 11 left wing, 12 inside centre, 13 outside centre, 14 right wing, 15 full-back.
• Replacements: normally numbered from 16 upward on the match-day team sheet.

The numbers are a practical map for reading the game. They do not mean a player is frozen in one patch of grass for the whole match.

What the laws actually require

World Rugby Law 3 says each team has no more than 15 players in the playing area during play. A match organiser may authorise matches with fewer than 15 players, and for non-international matches the organiser sets the number of replacements up to the law maximum.

The laws care most about player numbers, legal entry, safety, and front-row eligibility. They do not turn every attacking move into an offence just because a winger appears at first receiver or a flanker carries in midfield.

Front row: loosehead, hooker, tighthead

The front row is made up of the two props and the hooker. These are specialist positions because they take the direct pressure of contested scrums.

• 1 loosehead prop: packs on the left of the hooker, with the head on the outside of the opposition tighthead.
• 2 hooker: packs between the props, usually strikes for the ball in the scrum and throws into lineouts.
• 3 tighthead prop: packs on the right of the hooker, with the head between two opponents in a tighter scrum position.

Before the match, teams must identify their front-row players and the front-row positions they can play. Only suitably trained and experienced players should pack down in a contested front row.

Locks: the second row

Numbers 4 and 5 are the locks, also called second rows. In the scrum, they bind behind the front row and provide much of the shove. In lineouts, they are often the main jumpers or receiving targets because height and reach matter.

Locks also do heavy work around rucks, mauls, kick receipts, and close carries. The two lock numbers do not usually carry separate legal duties, but coaches may use them differently depending on size, lifting combinations, and lineout calls.

Back row: flankers and number eight

The back row completes the scrum behind and beside the locks. These players are forwards, but they often have to cover space quickly because they break away from the scrum and arrive early at tackles and rucks.

• 6 blindside flanker: often works the narrower side of the scrum and defends or carries in tighter channels.
• 7 openside flanker: often attacks the wider side and is commonly involved in breakdown contests.
• 8 number eight: packs at the back of the scrum, controls ball at the base, and links forwards with the scrum-half.

The blindside and openside labels describe sides of the field, not fixed left and right positions. Some teams and countries also use the 6 and 7 labels differently, so read the role in context.

Half-backs: scrum-half and fly-half

Numbers 9 and 10 are the main organisers in many phases. The scrum-half links the forwards to the backs, while the fly-half usually directs the next attacking choice.

• 9 scrum-half: feeds the scrum, passes from the base of scrums, rucks, and mauls, and manages tempo around the breakdown.
• 10 fly-half: receives many first passes from the scrum-half, kicks tactically, distributes to centres, and often calls attacking shape.

These roles can overlap. A full-back, centre, or second playmaker may take first receiver, and the scrum-half may kick or run instead of passing.

Centres and wings

The outside backs and centres are where many attacking movements become visible. They defend channels, chase kicks, carry into space, and turn possession into territory or tries.

• 11 left wing: usually starts on the left edge and is often used for finishing, kick chases, and back-field coverage.
• 12 inside centre: plays outside the fly-half and may be a strong carrier, passer, second kicker, or defensive organiser.
• 13 outside centre: defends and attacks wider channels, where timing and decision-making can create breaks or shut them down.
• 14 right wing: usually starts on the right edge and has a similar finishing and chasing role to the left wing.

Wings do not have to stay on the touchline. Modern teams often move wings into midfield, around rucks, or into the back field depending on the phase.

Full-back: the back-field organiser

The full-back wears 15 and usually begins behind the main defensive line. The role is heavily connected to catching kicks, covering space, returning kicks, counter-attacking, and acting as a last defender when the line is broken.

In attack, the full-back may join the line as an extra passer or runner. In defence, the full-back may organise the back field with the wings so the team can cover kicks without leaving the front line too thin.

What numbers 16 to 23 mean

At international level, a team may nominate up to eight replacements, which is why match-day squads often run from 1 to 23. Other matches may use fewer replacements, subject to the match organiser and the law limits.

Replacement numbers do not always map perfectly to one position, but teams must have enough front-row cover for the squad size. A bench may also be described by its forward-back split, such as more forwards than backs, but that is a selection choice rather than a separate law of positions.

For the return rules, temporary replacements, HIA procedures, and tactical changes, see the rugby union substitutions and replacements guide.

Where positions matter most

Positions are most strictly visible at set pieces. At a full 15-a-side scrum, each team normally forms with two props and one hooker in the front row, two locks in the second row, and three back-row players completing the scrum.

Lineouts are more flexible, but roles still matter. Hookers commonly throw, locks and back-rowers commonly jump or lift, and backs position themselves for the next phase. For the detailed restart rules, use the guides to scrums and resets and lineouts and knock-ons.

Players can change roles during play

The number on a shirt identifies the player for the team sheet and gives the usual starting role. It does not stop a prop from carrying in open play, a centre from kicking, a wing from defending deep, or a fly-half from moving wider.

Teams also reshuffle after substitutions, injuries, yellow cards, red cards, tactical moves, and defensive system changes. Officials do not penalise normal positional rotation. They intervene when the team has too many players, an ineligible front-row player is used, a replacement enters illegally, or a player is offside or otherwise infringing under the phase-specific laws.

When the numbering can differ

The 1-to-15 position list is the standard modern guide for 15-a-side rugby union, but it is not the only rugby numbering tradition ever used. Some historic, school, club, regional, or modified formats may use different conventions or fewer players.

Rugby sevens is a separate seven-a-side union format with different team size and spacing. Rugby league is a separate 13-a-side code with its own position structure. Do not assume a union team sheet, a league team sheet, and a sevens team sheet use the same logic.

What fans often misunderstand

• "The number is the rule": not exactly. The number is the normal position convention; the enforceable law issues are player count, eligibility, offside, entry, and phase duties.
• "Forwards never pass or kick": false. Forwards can pass, kick, carry, tackle, and score like any other player, though their usual tasks differ.
• "Back row means backs": no. The back row is still part of the forward pack: 6, 7, and 8.
• "The hooker is just a lineout thrower": no. The hooker is also a front-row scrum specialist.
• "Number 8 is just another flanker": no. The number eight has a distinct role at the back of the scrum and often links with the scrum-half.
• "A player must stay in the same channel all game": no. Rugby positions describe roles, not fixed zones like lanes on a track.

How officials interpret positions

1. Check that each team has no more than 15 players in the playing area during play.
2. Manage replacements only when the ball is dead and with the referee's permission, unless a specific medical process requires action.
3. Confirm front-row players and replacements are identified for contested scrum safety.
4. At scrums, require the correct front-row and scrum formation when the team has the necessary players available.
5. Order uncontested scrums if a team cannot safely field a suitably trained front row, or if the referee otherwise orders it.
6. Judge players by what they do in the phase: offside position, illegal entry, obstruction, foul play, or set-piece infringement matters more than the label on the team sheet.

Source material

• World Rugby Passport: Law 3 Team
• World Rugby Passport: Law 19 Scrum
• World Rugby Passport: Definitions
• World Rugby Laws of the Game