The tackle creates the contest; the ruck controls it.

How tackles and rucks connect

A tackle happens when a ball-carrier is held and brought to ground by one or more opponents. Once the ball-carrier is on the ground, the tackler, tackled player, and arriving players each have immediate responsibilities so the ball can be played.

A ruck is the next possible phase. It forms only in the field of play, with the ball on the ground, when at least one player from each team is on their feet, in physical contact, and over the ball. Until that ruck forms, the tackle law controls who may play the ball and from where.

Why the breakdown is so important

In sevens, there are fewer support players near each tackle. The ball-carrier may be isolated, the first tackler may have a real chance to compete, and one missed cleanout can leave the attack without quick possession.

The same law detail can matter more than it appears to in 15-a-side rugby. A penalty at one ruck can move the ball into open field, and a single legal turnover can become a try because there are fewer defenders behind the breakdown.

What the tackler must do

Once both players have gone to ground, the tackler must immediately release the ball and the ball-carrier. The tackler must also move away from the tackled player and the ball or get back to their feet before trying to play the ball.

If the tackler stays on the wrong side, traps the ball-carrier, plays the ball from the ground, or prevents the tackled player from releasing, the usual outcome is a penalty. A tackler who gets back to their feet and comes from the direction of their own try line may then compete, provided a ruck has not already formed.

What the tackled player must do

The tackled player must make the ball available immediately. They can release it, pass it, push it backwards, or place it in any direction, but they cannot hold on and wait for support if an opponent is legally contesting.

The tackled player must also move away from the ball or get up when required. If they lie on, over, or near the ball in a way that prevents opponents from gaining possession, the referee can award a penalty for not releasing or not making the ball available.

Entry must be legal and upright

Support players and defenders arriving at the tackle must be on their feet and come from the direction of their own try line before playing the ball. In practical terms, they must enter through their side of the tackle area, not around the side of the contest.

Players also need to support their own body weight. Diving past the ball, sealing the ball off, falling over the tackled player, or clearing an opponent dangerously can turn a promising attacking cleanout into a penalty against the attacking team.

When the ruck has formed

A ruck forms when the ball is on the ground and at least one player from each team is on their feet, in contact, and over it. The moment matters because it changes what players can do with their hands and where the offside line sits.

Before a ruck forms, a legal player on their feet may be able to pick up or win the ball. After a ruck forms, players generally cannot handle the ball in the ruck unless they had hands on it legally before the ruck formed and remain on their feet.

The ruck creates a new line

At a ruck, each team has an offside line running parallel to the try lines through the hindmost point of any ruck participant on that team's side. Players not in the ruck must stay behind that line until the ruck ends.

This is one of the most common sevens breakdown penalties. A defender who steps around the side, reaches in from in front of the hindmost point, or tackles the scrum-half before the ball is out is likely to be offside.

How possession can change

At the tackle, the defence can win possession if a player complies with the tackle law, stays on their feet, and legally gets to the ball before a ruck forms. This is often called a jackal or breakdown steal, but the nickname does not change the legal test.

Once a ruck forms, possession is usually won by driving over the ball, pushing opponents off it, or making the ball available at the back. Players may play the ball with their feet in a safe way, but they cannot kick or attempt to kick the ball out of a ruck.

When the ruck ends

A ruck ends when the ball leaves the ruck, when the player playing it away has lifted it from the ground, or when the ball in the ruck is on or over the try line. Until then, defenders must keep respecting the ruck offside line.

If the ball has clearly been won and is available, the referee can call for it to be used. After that call, the ball must be played away within five seconds. If it is not, the sanction is a scrum to the other team.

What happens when it gets stuck

If the ball becomes unplayable at a tackle or ruck, the referee works out whether a player has offended. If someone held on, failed to roll away, entered illegally, collapsed the contest, or sealed the ball off, the referee can award a penalty.

If the ball will probably not emerge and no clear offence is identified, play can restart with a scrum. At a ruck, the throw-in normally goes to the side that was last moving forward before the stoppage.

High and dangerous tackles are separate

The tackle and ruck laws sit alongside foul play law. A tackle must meet the relevant tackle-height and safety standards for the level being played, and dangerous contact can be penalised even if the tackler also releases properly afterward.

At the ruck, officials watch cleanout height, shoulder contact, neck rolls, twisting, collapsing, and players going off their feet. Sevens does not make those actions less serious; because there is more space, dangerous or cynical breakdown offences can have a large effect on the game.

Where people get caught

• "The tackler made the tackle, so they can take the ball": only after releasing, moving away or getting up, and playing from a legal position before a ruck forms.
• "The first player over the ball always wins it": no. They must be on their feet, enter legally, support body weight, and comply with the tackle law.
• "Hands are allowed because the ball is still visible": not once a ruck has formed, unless the player had hands on legally before formation and stays on their feet.
• "Small sevens rucks do not create offside lines": they do. One player from each team over the ball is enough if the other ruck requirements are met.
• "The ball is out when defenders can see it": visible is not the same as out. Officials judge whether the ruck has legally ended.

How to read the call

1. Identify whether there was a tackle: the ball-carrier was held and brought to ground.
2. Watch the tackler: release, move away or get up, and approach from the correct side before playing the ball.
3. Watch the tackled player: release, place, pass, or otherwise make the ball available immediately.
4. Check arriving players: on feet, through their side, supporting body weight, and making safe contact.
5. Decide whether a ruck formed: ball on ground, players from both teams on feet, in contact, and over it.
6. Apply the outcome: play on, turnover, penalty, scrum for unplayable ball, or advantage if the non-offending team benefits.

Source material

• World Rugby Law 14: Tackle
• World Rugby Law 15: Ruck
• World Rugby Law 13: Players on the ground in open play
• World Rugby Law 9: Foul play
• World Rugby Sevens variations
• World Rugby Laws of the Game