Rugby Offside Law Explained: Every Offside Line in Union

Twickenham, a Saturday in February, and the referee's arm goes out horizontally while the crowd is still watching the ball land forty metres downfield. Nobody near the ball has done anything. The penalty is for a flanker standing still, twelve metres behind play, who happened to be in front of his own scrum-half when the kick went up and did not move.

Offside accounts for a very large share of the penalties awarded in a rugby union match, and almost none of them look like offences to a casual spectator. That is because offside in union is not one law with one line. It is a family of separate lines, each of which appears at a different moment, sits in a different place, and disappears the instant the phase it belongs to ends.

World Rugby's Law 10 covers offside and onside in open play. The other lines live inside the laws governing the ruck, the maul, the scrum and the lineout, which is a large part of why the subject is so hard to hold in one piece. This page puts them together.

The principle: in front of the team-mate who last played the ball

Strip away every set piece and one sentence remains. A player is offside if they are in front of a team-mate who is carrying the ball, or in front of a team-mate who last played it.

Everything else in the law is a specialised version of that idea. The reason rugby is played in a backwards-passing line is not the forward pass law alone. It is that a player ahead of the ball is out of the game until something puts them back into it, so a team's entire shape has to be built behind whoever has possession.

Note what the principle measures against. Not the ball's position — the position of the team-mate. A player standing behind the ball but in front of the team-mate who kicked it is offside, which is the situation that produces most of the penalties nobody in the ground understands.

Note also who it does not apply to. The opposition are never offside by reference to your players. Offside is entirely a relationship within one team, which is why a defender can stand anywhere in open play without committing anything, and why the offside lines that constrain defences all come from set pieces and the breakdown rather than from Law 10's basic principle.

Being offside is not, by itself, an offence

This is the single most useful thing a spectator can learn about the law, and it explains why referees let so much go.

A player in an offside position has done nothing wrong. They become liable to sanction only when they do one of a small number of things: interfere with play, move forward towards the ball, or fail to comply with the ten-metre law after a kick. A forward who ends up in front of the ball, stops dead and puts his hands in the air is complying with the law rather than getting away with something.

Interfering with play covers the obvious — playing the ball, tackling a carrier, obstructing an opponent — and also the less obvious, such as standing in a position that prevents an opponent from running a line they would otherwise have run.

"Moving forward towards the ball" is the one that produces most penalties. An offside player who drifts two steps in the direction of play has committed the offence, whether or not anything came of it, because the law treats moving forward as interference in itself.

The usual sanction is a penalty kick at the place of the offence. There are variations, and the most important is accidental offside, which is dealt with further down and produces a scrum rather than a penalty.

Getting back onside in open play

1. 1RetreatThe offside player moves behind the team-mate who last played the ball. The simplest route and entirely within your own control.
2. 2The carrier passes youA team-mate carrying the ball runs in front of you, and you are onside from that moment.
3. 3The kicker passes youA team-mate who was behind the kicker at the moment of the kick runs in front of you. This is what the chase is for.
4. 4Opponent runs five metresAn opponent carries the ball five metres, and every offside player is put onside.
5. 5Opponent kicks or passesAn opponent kicking or passing the ball puts offside players onside.
6. 6Opponent touches the ballAn opponent who intentionally touches the ball without catching it also puts offside players onside.

The provisions of Law 10. A player subject to the ten-metre law cannot be put onside by any opposition action until they have retired.

Two families of action, and the distinction matters because only one of them is available to you.

Your own team can put you onside by retreat or by overtaking. Retreating behind the last player to play the ball is always available and is what a forward does when he realises the kick has gone over his head. Being overtaken is what happens when the fly-half kicks and then sprints through, or when a team-mate who was legitimately behind the kicker chases past.

The opposition can put you onside by three actions: running five metres with the ball, kicking or passing it, or intentionally touching it without gathering it. The logic is that once the opposition have chosen to play, the passage of play that made you offside has ended.

The exception is where it gets strict. A player caught by the ten-metre law cannot be put onside by anything the opposition do. They retreat, or an onside team-mate runs past them, and until one of those happens they are offside no matter how many opponents have handled the ball.

The offside lines at ruck and maul: the hindmost foot

Once a ruck forms, the whole geometry changes. Each side gets an offside line running through the hindmost point of the hindmost player in the ruck, parallel to the goal line and extended across the full width of the pitch.

That line is invisible, it moves constantly as bodies arrive and the ruck shunts forward, and it is the most heavily policed line in the game. A defender standing a foot in front of it, doing nothing, is offside and penalisable.

The maul works identically. Hindmost foot, parallel to the goal line, both sides. Because a maul travels, the line travels with it, which is why the defending back row spends a driving maul walking backwards with their eyes on the referee rather than on the ball.

Two consequences follow that spectators rarely separate. The first is joining: a player entering a ruck must come from behind their own offside line, which is the "through the gate" requirement. The second is standing: a player not joining must stay behind the line until the ruck ends. Different obligations, both commonly called offside by commentators.

A ruck ends when the ball leaves it, when the ball is on or over the goal line, or when the referee calls it unplayable. At that instant the offside lines vanish and open play resumes, which is why a defender can appear to sprint from an offside position without penalty — the ruck ended half a second before the eye registered it. The mechanics of the contest itself are set out in the breakdown laws guide.

The scrum: five metres back, and the scrum-half's own arrangement

• 5Scrum, players not in the scrum, metres
• 10Lineout, players not in the lineout, metres
• 10Ten-metre law after a kick, metres
• 1Gap between the two lineout lines, metres

Distances specified in the laws of the game. They apply to the phases named and nowhere else.

At a scrum there are two separate arrangements running at once, and confusing them is the reason people think the law is arbitrary.

For every player not in the scrum, the offside line is five metres behind the hindmost foot of their own team's scrum, parallel to the goal line. That is why the backs stand so deep, why the fly-half receives the ball already running, and why a defence cannot compress the space at a scrum the way it can at a ruck. Five metres is a great deal of room when the ball comes out quickly.

The two scrum-halves are treated differently, because otherwise the scrum could not function. Their positions are governed by the ball rather than by the five-metre line, so the nine of the side putting in follows the ball round the scrum while the nine of the defending side is held to the ball's position and must not move beyond it.

That is the source of one of the game's regular flashpoints. A defending scrum-half who creeps around the flank to pressure the base is doing something the law constrains tightly, and the referee's management of it varies more than most areas of the game. Some referees warn once. Some penalise immediately.

The five-metre line applies until the scrum ends, and the scrum ends when the ball leaves it. A back row detaching early is a scrum offence rather than an offside one. The engagement sequence and the rest of it are covered in the scrum laws guide.

The lineout: ten metres back, and the metre in the middle

The lineout produces more offside lines than any other phase, which is why the referee spends the seconds before the throw looking sideways rather than at the thrower.

Players not taking part in the lineout must stand ten metres behind the line of touch, or on their goal line if that is nearer. Ten metres is a lot, and it is the reason a lineout creates so much attacking space in midfield. A defence that could stand five metres back from a lineout would strangle it.

Players taking part have the line of touch itself as their offside line until the ball has been thrown in and touched. Cross it before then and you have offside at the lineout, which is what a forward commits when he anticipates the throw and steps across.

Between the two lines of forwards there is a gap of one metre, which the players on both sides must respect until the ball leaves the thrower's hands. It is a small distance and it is the difference between a lineout and a maul forming before anyone has caught the ball.

The receiver — the player standing off the back of the lineout, usually the scrum-half — stands two metres back, and that position has its own constraints.

The lineout ends in defined circumstances, and the moment it ends the ten-metre line disappears and the backs may advance. Judging that moment is one of the harder pieces of reading in the game for a defending centre, and getting it wrong by half a second is a penalty. The lineout laws guide sets out the throw, the lift and the ending conditions in full.

Phase	Where the offside line sits	Who it binds
Open play	The team-mate who last played the ball	Everyone in front of them
Ruck	Hindmost foot of the hindmost player	Both sides, until the ruck ends
Maul	Hindmost foot of the hindmost player, moving with the maul	Both sides
Scrum	Five metres behind the hindmost foot	All players not in the scrum
Scrum, scrum-halves	Governed by the position of the ball	The two nines
Lineout, participants	The line of touch until the ball is thrown and touched	Players in the lineout
Lineout, non-participants	Ten metres behind the line of touch	Backs and any forward not in the lineout
After a kick	Ten metres from where the ball lands or the receiver stands	The kicker's team-mates in front of him
Penalty and free kick	Ten metres back towards their own goal line	The non-kicking side

Kick chase: why the wing checks his stride and looks back

The clearest illustration of Law 10 in the whole game is a wing running at full speed, then stopping dead and turning his head.

When a fly-half kicks, every team-mate in front of him at the moment of the kick is offside. Not when the ball lands — at the moment of contact. A wing who has already started running to chase is therefore offside before the ball is in the air, and everything he does afterwards is governed by that.

There are two lawful ways out. He waits until the kicker, or a team-mate who was behind the kicker when the kick was struck, runs past him. Or he retreats behind that player. In practice the chase is organised so that a designated player — often the full-back or a back-rower who deliberately stayed deep — sweeps through and plays the front of the chase onside as he goes.

Watch a professional kick chase with that in mind and it stops looking like a race. There is a line of players moving at three-quarter pace, one player coming through them at full speed, and the whole line accelerating in a wave as he passes. That wave is the law being obeyed in real time.

The wing who checks and looks back is doing arithmetic: has anybody passed me yet, and can I go?

The ten-metre law and the zone nothing can rescue you from

1. 1The kickThe ball is struck. Every team-mate in front of the kicker at that instant is offside.
2. 2The zoneAn imaginary line ten metres from where the ball lands, or from the opponent waiting for it, runs across the pitch.
3. 3Inside the zoneA player in front of the kicker and inside those ten metres must move away from the ball immediately.
4. 4No rescueWhile in that zone they cannot be put onside by anything an opponent does. Only retreat, or an onside team-mate passing them, works.
5. 5The catchAn opponent who catches the ball is entitled to do so without an offside player closing him down.
6. 6The sanctionA penalty. The non-offending side can usually take a scrum where the kick was made instead.

The sequence set out in Law 10 for a kick in open play. The ten-metre line is imaginary and runs across the full width of the pitch.

The ten-metre law is what stops a kick chase becoming a scrimmage around a defender in the air, and it is the strictest provision in Law 10.

Two reference points define the zone. Where the ball lands, and where an opponent is waiting to play it — whichever produces the line the player is inside. From that line, ten metres back, an imaginary line runs across the whole width of the pitch, and a player of the kicking team who is in front of the kicker and inside it must retire.

Must retire, and must retire immediately. Standing still is not compliance. Nor is standing still with your hands up, which is enough in ordinary open play and is not enough here.

The reason the law is severe is that the alternative is dangerous. A player waiting under a high ball, eyes up, is at his most vulnerable, and a chaser arriving from an offside position gets there before the defender can protect himself. The ten-metre zone is player-safety law dressed as offside law, and referees treat it accordingly.

Sanction is a penalty kick, and the non-offending side is generally given the alternative of a scrum where the kick was taken, which can be the better option when the kick has gained ground.

Retiring players, and the difference between standing still and getting out of the way

Two obligations sit under the same word and they are not equivalent.

In ordinary open play an offside player is required not to interfere. Standing still, not moving forward and not obstructing anybody satisfies the law completely, and a forward who has been left in front of the ball can simply stop where he is and wait to be played onside. Referees see this constantly and say nothing, because nothing is wrong.

After a kick, inside the ten metres, the obligation changes from passive to active. The player must move away from the ball, and must do it without delay. A player who stands still there, however innocently, is committing an offence.

There is a third version at penalties and free kicks, and it has its own distance. The non-kicking side must retire ten metres towards their own goal line, or to the goal line if it is nearer, and must not advance until the kicker has kicked. A defender who trots back at his own pace while the kicker is already tapping and going is offside, and the referee's remedy — advancing the mark ten metres — is one of the sharpest sanctions in the game because it converts a kickable penalty into a certain three points.

The same principle applies at a kick-off and at restarts, where the kicking team must be behind the ball when it is struck. Nobody notices this law until a chaser crosses early and the referee brings it back.

What links all four is a distinction referees draw and players routinely miss. Being out of the game is sometimes enough, and sometimes the law requires you to be visibly getting out of the way. The test in the second case is not whether you affected play. It is whether you moved.

Accidental offside and what it actually produces

Not every offside is a decision. A player standing legitimately in a defensive line whose own team-mate runs into him with the ball has done nothing at all, and the law recognises that.

Accidental offside covers the case where an offside player cannot avoid being touched by the ball, or by a team-mate carrying it. The test is unavoidability rather than intention.

Two outcomes follow. If the offending team gains no advantage from the contact, play continues and nothing is said. If the team does gain an advantage — the ball rebounds usefully, the collision takes a defender out of the play, possession is retained because of it — the referee awards a scrum to the opposition.

A scrum, not a penalty. That distinction is the law being proportionate: a side that has profited by accident loses the ball, and a side that has profited deliberately loses ten or twenty metres and possibly three points.

The most common instance is a support runner clattering into his own ball carrier at pace, and the second most common is a ball bouncing back off an offside player's leg. Neither is cheating. Both can be worth a scrum.

Offside at the tackle, and the gate that is not an offside line

Here is the awkward truth about the area of the game where "offside" is shouted loudest: at a tackle, before a ruck has formed, there is no offside line at all.

A tackle is not a ruck. Until at least one player from each side is on their feet and in contact over the ball, no offside lines exist, and players may arrive from any direction — provided they are on their feet and enter from behind the ball. That last requirement comes from the tackle law rather than from Law 10, and it is what the game calls the gate.

Referees penalise players who come in from the side of a tackle constantly, and commentators call it offside constantly, and it is very often not offside. It is failing to enter through the gate, or playing the ball off your feet, or joining from an opponent's side. The sanction is the same penalty, which is why nobody outside the officiating community has any reason to care about the distinction.

Where it stops being a pedantic point is when a player is deciding what to do. A defender arriving at a tackle before a ruck forms has options he loses the moment the ruck forms, and the good jackals in English rugby are the ones who understand exactly how narrow that window is. Half a second earlier and the ball is legitimately contestable from an angle. Half a second later and the same movement is a penalty.

How referees actually police the lines

The offside line is imaginary, moves constantly, and has to be judged by one person standing in a moving game.

Referees solve that partly by positioning. At a ruck a referee will typically stand on the defending side, close to the hindmost foot, using their own body as a physical marker of where the line is. Players are watching the referee's feet as much as the ball, which is why a referee who drifts out of position gets a defensive line that creeps.

They solve it partly by talking. Offside is the most verbally managed law in rugby union, and a large fraction of what a microphone picks up during a match is a referee holding a defensive line back: a number, a colour, an instruction to retreat. Managing rather than penalising is a deliberate choice, and its justification is that a game stopped every time a flanker is half a metre up is not a game anybody wants to watch.

Assistant referees take a share of it, particularly the far-side line at scrums and lineouts and the ten-metre law after a kick, which the referee often cannot see because they are following the ball. The television match official's remit is defined and does not extend to policing routine offside — that scope is set out in the TMO protocol guide.

What follows from all this is a genuine inconsistency between referees, and pretending otherwise is dishonest. Two officials in the same competition will apply different tolerances to a defensive line that is creeping, and a coach's pre-match briefing at every level in England includes some version of "find out early how much this one is giving you". That is a feature of a law policed by judgement rather than a failure of the officials. Anyone curious about how those judgements are trained will find the route described in the guide to becoming a referee in England.

Why rugby league's ten metres looks like a completely different law

A spectator switching between the codes on a winter weekend sees two versions of offside that barely resemble each other, and the difference is structural rather than cosmetic.

Rugby league has no ruck in the union sense, so there is no hindmost foot to measure from. Instead the defending side must retire ten metres from the play-the-ball after every tackle, with the exception of two markers who may stand at the play-the-ball itself. The line is straight, it is ten metres, and it re-forms after every single tackle.

That produces a completely different visual. League defences are flat, spread across the pitch, and retreating in unison between tackles, and the officials police the line as an absolute distance rather than as a judgement about a moving pile of bodies. Union defences are ragged around a breakdown because the line they are holding is defined by whoever happens to be hindmost.

Both codes share the underlying principle — a player in front of a team-mate who last played the ball is out of the game — and diverge in everything built on top of it. The two rule sets are compared properly in the league and union rules guide, and the six-tackle structure that gives league its shape is covered in its own guide.

For anyone learning union's version, the practical advice from referees across the English club game is consistent and slightly deflating. Do not try to hold all nine offside lines in your head. Learn one thing — where the hindmost foot is — because it covers the ruck and the maul, and those account for the overwhelming majority of the phases in a match. The rest can be picked up a set piece at a time, and more of the English game is covered across the rugby section.