The scrum is one of the most recognisable images in rugby union: sixteen forwards bound together, heads down, driving for possession. But behind that wall of bodies sits a tightly governed contest with its own laws, positions and safety rules. This guide explains, in plain English, what a scrum is, why it happens, who does what in the pack, and how referees keep it safe and fair. Examples are pitched at the New Zealand game, from Super Rugby Pacific down to the Bunnings NPC and community grades.
Key Points
- What it is: a contest for possession that restarts play after a minor error, using eight forwards per team.
- The pack: three rows — front row (1–3), second row/locks (4–5) and back row (flankers 6–7 plus number 8).
- Engagement: the referee calls “Crouch, Bind, Set” for a safe, controlled coming-together.
- The feed: the halfback rolls the ball into the tunnel; only the front row may strike for it.
- Offside line: backs must stay five metres behind the hindmost foot of the scrum.
- Sanctions: technical errors give a free kick; dangerous or deliberate offences give a penalty.
Why a Scrum Happens
A scrum is a way of restarting play after a minor, non-deliberate mistake. It is not a punishment like a penalty; it is a neutral way to get the ball back into open play while giving both teams a fair chance to win it. Eight players from each side — the forwards, collectively called the “pack” — bind together in three rows and push against their opposite numbers, competing for the ball that is fed into the gap between them.
The most common reasons a referee awards a scrum are:
- Knock-on: a player loses the ball forward off the hand or arm.
- Forward pass: the ball is thrown towards the opposition’s goal line rather than sideways or backwards.
- Ball unplayable: the ball becomes trapped and cannot be won at a tackle or ruck. If you are new to that phase, our guide to the ruck and breakdown explains how a scrum can result when the ball gets stuck.
The team that did not make the mistake gets to feed the ball into the scrum, which gives them a strong chance of winning it back. Unlike some restarts, the union scrum is fully contestable: both packs are allowed to push, and a dominant pack can shove the other backwards, win the ball against the feed, or earn a penalty.
The Eight Forwards: How a Pack Is Built
A scrum uses the eight forwards from each team, arranged in three rows. Each player wears a set jersey number that tells you their job. Understanding the numbers is the quickest way to read a scrum — for the wider system, see our full guide to rugby positions and jersey numbers.
Scrum Positions at a Glance
| Position | Number | Row | Main job in the scrum |
|---|---|---|---|
| Loosehead prop | 1 | Front | Give the hooker a stable platform on the open side |
| Hooker | 2 | Front | Strike (“hook”) the ball back with a foot |
| Tighthead prop | 3 | Front | Anchor the scrum against two opponents |
| Lock | 4 | Second | Provide forward drive; bind with lock and prop |
| Lock | 5 | Second | Provide forward drive; bind with lock and prop |
| Flanker | 6 | Back | Add sideways stability; break to tackle |
| Flanker | 7 | Back | Add sideways stability; break to tackle |
| Number 8 | 8 | Back | Control the ball at the base; pick and go |
The Front Row
The front row takes the impact and is the only part of the pack that makes direct contact with the opposition. It has three players:
- Loosehead prop (1): packs down on the left of the front row, so their head sits on the outside of the scrum — the “loose” head. Their main job is to stay strong and give the hooker a stable platform.
- Hooker (2): the middle player, who “hooks” the ball backwards with a foot once it is fed in. The hooker also throws the ball at lineouts.
- Tighthead prop (3): packs down on the right, with their head wedged between the opposition hooker and loosehead — the “tight” head. This is one of the most physically demanding positions on the field, because the tighthead absorbs pressure from two opponents at once.
Props must bind correctly onto their opponents, using a full arm to grip the jersey. A grip that is too short, or letting go mid-scrum, is an offence because it makes the scrum unstable and unsafe.
The Second Row and Back Row
If the front row is the point of contact, the players behind them are the engine. The two locks (4 and 5) are usually the tallest players in the team. They bind together, put their heads between the props and hooker, and provide most of the forward drive. The back row adds power and control:
- Flankers (6 and 7): bind onto the sides of the scrum, give it sideways stability, and are first to break away to tackle or chase once the ball is out.
- Number 8: binds at the very back between the two locks. The number 8 controls the ball with their feet once it reaches the base and can pick it up to run or pass.
Because the pack has to move as one unit, the raw power of the second and back rows only counts if it is transferred cleanly through a stable front row. That is why forward conditioning matters so much; see our guide to strength training for forwards for how packs build that base.
Crouch, Bind, Set: The Engagement Sequence
To stop two packs from smashing into each other at speed — a major cause of neck and spine injuries in the past — World Rugby controls the engagement with three referee calls. Introduced globally in 2013, the sequence has sharply reduced the forces involved in the initial hit.
- “Crouch”: both front rows bend into a stable, braced position with their heads and shoulders no lower than their hips.
- “Bind”: each loosehead prop reaches out and grips the jersey of the opposing tighthead, setting a fixed distance between the packs before contact.
- “Set”: the packs come together under control and the tunnel — the gap between the two front rows — is formed, ready for the ball.
The packs must stay square, stable and stationary at each call. Engaging early, or pushing before the ball is in, is a technical offence and usually results in a free kick.
Feeding the Ball and Winning Possession
Once the scrum is set, the scrum-half (number 9, called the halfback in New Zealand) rolls the ball into the tunnel. Law 19 requires the feed to be straight so both hookers have a fair chance to strike for it, although in practice referees have often allowed the halfback to align with the middle of the scrum. Only front-row players may strike for the ball; everyone else must stay bound.
When the hooker wins the strike, the ball travels back to the number 8’s feet. It is “out” once it has left the scrum — typically when the halfback picks it up or the number 8 breaks with it. If the ball is available at the back and the scrum is stationary for roughly three to five seconds, the referee will call “use it,” and the team must then play it without further delay. This is a referee’s judgement call, not a fixed stopwatch rule.
Two other rules shape the contest. If a scrum wheels (rotates) more than 90 degrees, the referee stops play and orders a reset for safety. And the players not bound into the scrum — the backs — must stay behind an offside line five metres back from the hindmost foot of the scrum, which is what creates the attacking space described below. For how these markings sit on the pitch, see our explainer on rugby field dimensions.
Common Scrum Offences: Free Kick or Penalty?
Because the scrum is powerful and potentially dangerous, it is heavily policed. The referee has two main sanctions. A free kick is for technical, low-risk errors: the team may tap and run or kick for touch but cannot kick directly at goal. A full penalty is for dangerous or deliberate offences and can be kicked at goal or for territory.
- Collapsing: pulling or driving the scrum to the ground is dangerous play and is penalised, especially if judged deliberate.
- Boring in: a prop angling their head and body inwards to disrupt an opponent, rather than pushing straight.
- Early engagement or early push: moving before the call or before the feed — usually a free kick.
- Not straight / handling in the scrum: a crooked feed or a player using hands on the ball in the scrum — usually a free kick.
- Illegal wheeling: deliberately rotating the scrum, or wheeling it past 90 degrees, which forces a reset.
| Offence | Typical sanction | Why |
|---|---|---|
| Deliberate collapse | Penalty | Dangerous play; injury risk |
| Boring in / not pushing straight | Penalty | Unfairly disrupts the contest |
| Early push or engagement | Free kick | Technical timing error |
| Crooked feed / hands in scrum | Free kick | Technical, low-risk error |
Referees also watch which pack is dominant. If one team is legally driving the other backwards and the retreating side goes to ground, the sanction usually goes against the team that could not hold the drive.
The Scrum as an Attacking Platform
A scrum is more than a restart — it is one of the best launch platforms in the game because it ties sixteen forwards into one spot. With the pack committed, the attacking backs have space to run set-piece moves, and the five-metre offside line gives them a head start on the defence. This is why coaches drill strike plays from scrums; our guide to set-piece strategies shows how teams turn a scrum into points.
- Space creation: forwards are locked in, leaving fewer defenders across the wide channels.
- Planned strikes: a stable scrum gives a predictable starting point for moves such as the number 8 pick-and-go or a backline wrap.
- Penalty advantage: a dominant scrum can win a penalty, letting the backs attempt a high-risk play knowing the whistle protects them.
- Wearing the opponent down: repeatedly driving a pack backwards drains their energy for the rest of the match.
Safety, Uncontested Scrums and Community Rugby
Player welfare drives most modern scrum law. New Zealand Rugby’s RugbySmart programme teaches a safe body position from a young age: a flat back, hips no lower than shoulders, a braced core and a straight spine so force is absorbed through the frame rather than the neck. Getting this wrong is both a safety risk and a fast way to concede a penalty. Sound technique also underpins staying fit — see our advice on injury prevention.
Age-grade and community rugby scale the contest down. From “Small Blacks” level upwards, young players learn body position first, and many junior grades cap how far a scrum may be pushed (for example, around 1.5 metres) or use uncontested scrums so power never outweighs safety.
Uncontested Scrums Explained
Sometimes a scrum becomes “uncontested.” This happens when a team cannot safely field a trained front row — usually through injuries or cards to specialist props or the hooker. In an uncontested scrum the packs bind but no pushing or striking is allowed, and the team feeding the ball automatically wins it. In many competitions, if a team causes uncontested scrums by running out of front-row cover, it must also play a player short. The scrum still forms, so the backs keep their attacking space, but the physical contest is removed.
How Recent Law Changes Affect the Scrum
Rugby’s laws are regularly trialled to make the game safer and faster. From 2025, World Rugby’s global law trials gave the scrum-half added protection at scrums, rucks and mauls, and tightened the clock elsewhere with a 30-second lineout set-up and a 60-second limit on conversions. These do not change how the scrum is formed, but they speed up the play around it.
For 2026, Super Rugby Pacific added its own trials aimed at fewer stoppages. The most relevant to this topic is that a scrum is no longer awarded for accidental offside or for delaying playing the ball away from a ruck — a free kick is used instead, keeping play moving. Other 2026 trials cover the ruck (no extra players joining after the “use it” call), a more flexible 50/22 and a wider quick-tap area, and make a card discretionary rather than automatic when a penalty try is awarded. There has been debate about whether such changes “depower” the scrum, which World Rugby disputes; the core Law 19 contest described in this guide remains in place. To see how teams use these tweaks in a match, read our guide to rugby game management.
Sources
Frequently Asked Questions
What is a scrum in rugby union?
A scrum is a way of restarting play after a minor error such as a knock-on or forward pass. Eight forwards from each team bind together in three rows and push against each other while the ball is fed into the gap between them, competing to win possession.
How many players are in a scrum?
A full scrum has sixteen players in total — eight forwards from each team. Only forwards take part; the backs stay outside the scrum behind an offside line five metres back from the hindmost foot.
What do the calls “Crouch, Bind, Set” mean?
They are the referee’s three commands for a safe engagement. “Crouch” gets both front rows into a braced position, “bind” has the props grip their opponents to fix the distance, and “set” is the signal for the packs to come together under control.
What is the difference between a free kick and a penalty at the scrum?
A free kick is given for technical errors such as a crooked feed or an early push, and the ball cannot be kicked directly at goal. A penalty is for dangerous or deliberate offences such as intentionally collapsing the scrum, and it can be kicked at goal or for territory.
What is an uncontested scrum?
It is a scrum in which no pushing or striking is allowed, used when a team cannot safely provide a trained front row. The packs still bind and the feeding team automatically wins the ball, and in many competitions the affected team must also play a player short.