A scrum is finished when the ball has come out of the scrum.

Once it has, then the opposition scrum-half can tackle their opposite number for the ball.

But in some situations the number 8 may dribble with the ball, keeping it in the scrum.

This means the opposing scrum-half cannot get their hands on the ball because it's still in the scrum.

This often happens when the team in possession have an attacking scrum near their opponent's try line.



RETAKING A SCRUM
The referee is in charge on the pitch and if he's not happy with a scrum, he can order it to be re-taken again when:

The scrum has rotated 90 degrees

The scrum has collapsed before the ball has been fed or before the ball has come out

The ball does not come out quick enough

When it comes to scrums, the hooker is the player with all the responsibility and pressure.

Their job is to strike the ball back to the number 8 once the scrum-half has fed the ball into the scrum.

This is not as easy as it sounds.

Why? Because the opposition's hooker is trying to steal the ball from you.

Plus you've got eight huge forwards on the other side trying to push you off the ball.

The hooker is the only player in the scrum who can raise their feet - otherwise they would never be able to strike the ball.

However, no other player in the scrum is allowed to handle the ball until the ball is free - not even the hooker.

The scrum-half is the player who gets things going in the scrum.

It is their job to feed the ball into the scrum for the hooker to strike back to the number eight.

The scrum-half can roll the ball in from either the left-hand side or the right-hand side of the scrum.

The scrum-half must then not handle the ball until it has come out of the scrum.

The six other backs must be at least five metres behind the off-side line running through the hindmost foot of the last forward in the scrum.

If they are not, the referee will penalise the offending team.

Two packs of players, straining every muscle for every inch of opposition territory they can claim.

Of course, it's the scrum.

It is used for restarting play after the following:

The ball has been knocked on

The ball has gone forward

Accidental offside

The ball has not come out from a ruck or maulNot every player can join a scrum. Only eight players from each team can take part.

They are almost always the eight forwards in the side.

The scrum is formed at the place where the infringement happened.

All scrums must take place at least five metres from the touch or trylines.

However the scrum is one of the hardest areas of the game to referee because of the many infringements, particularly in the front row.



BINDING
Referees pay particular attention to the bindings of the two front rows.

Props must use the whole arm from hand to shoulder to grasp their opponent's body at or below the level of the armpit.

They must grasp their opposite number's shirt from the side or the back.

They cannot go underneath and grab the collar or the sleeve of the upper arm.

Props often look for a late bind when they engage.

By maneuvering their arm they can manipulate their opponent's body position, giving them a significant advantage in the push.

However referees are stringent on this move because of safety reasons.

Twisting, dipping or collapsing a scrum will result in a penalty against the offending team.



FRONT ROW OFFENCES
Rather than engaging square on with their opponent, tight-head props can bore their heads into the hooker.

This limits the movement of the opposition hooker.

Sometimes you may see a tight-head prop's body pop out of a scrum while it is still taking place.

This is because their opposing loose-head prop has used a subtle shift of body position and pushed into the tight-head prop's chest.

Both moves are illegal and are punishable with penalties.

The eight forwards are the players who form the scrum.

The hooker, two props, two second rows, two flankers and the number eight all bind together in a 3-4-1 formation, ready to lock heads with the opposition.

The hooker
A key player in the scrum - their job is to hook the ball back towards the waiting scrum-half .

Two props
They make the hooker's life easier. They bind on tightly on both sides of the hooker, leaving no gaps between them, and try to drive the opposition back.The prop to the left of the hooker is called the loose-head because they have one arm free when they bind.

The prop to the right is called the tight-head because they slot in between the hooker and the opposition loose-head.

Two second row forwards
They bind tightly together and pack down behind the front row, putting their heads in the gaps between the hooker and the props.

Two flankers
Bind on to both the props and second rows on either side of the scrum.

Number 8
They pack down behind the second row forwards, putting their head between the two second rows.