The changes, that come into effect in the northern hemisphere on August 1, are aimed at making the scrum and ruck simpler to referee and easier to watch.
Players, coaches and referees were involved in a consultation process ahead of making the amendments official.
One of the changes relates to Law 20.8 (b) and it states that the team putting the ball into the scrum are now obliged to hook for it and it says that any front row player can use either foot to win possession.
This means that teams can no longer simply try and drive over the ball, which has resulted in stalemates and eventual collapses.
Elsewhere at the scrum, the No.8 will now be allowed to pick the ball out of the second rows' feet with the aim of helping to get the ball away from a scrum quicker.
Finally at the scrum, the referee will no longer prompt the scrum-half to feed the ball and the No.9 is able to stand with his outside shoulder in line with the middle of the scrum, meaning his closer to his own team. Though the ball must still be fed straight.
Under changes to Law 16, a ruck now begins when at least one player is on their feet and over the ball. Players on their feet can use their hands to get the ball as long as it's immediate and as soon as an opposing player arrives, hands can't be used.
Players are also no longer allowed to kick the ball through a ruck and must only hook it back towards their own side.
Finally, a tackler must return to his own side and come through 'the gate' before playing the ball. This prevents the now common situation where a tackler plays the ball from the wrong side before a ruck is formed.
The law changes in full
1. Law 20.5 and 20.6 (d)
No signal from referee. The scrum-half must throw the ball in straight but is allowed to align their shoulder on the middle line of the scrum, therefore allowing them to stand a shoulder width towards their own side of the middle line.
Rationale: To promote scrum stability, a fair contest for possession while also giving the advantage to the team throwing in (non-offending team).
2. Law 20.9 (b) Handling in the scrum – exception
The number eight shall be allowed to pick the ball from the feet of the second-rows.
Rationale: To promote continuity.
3. Law 20.8 (b) Striking after the throw-in
Once the ball touches the ground in the tunnel, any front-row player may use either foot to try to win possession of the ball. One player from the team who put the ball in must strike for the ball.
Rationale: To promote a fair contest for possession.
4. Law 15.4 (c)
The tackler must get up before playing the ball and then can only play from their own side of the tackle “gate”.
Rationale: To make the tackle/ruck simpler for players and referees and more consistent with the rest of that law.
5. Law 16 Ruck
A ruck commences when at least one player is on their feet and over the ball which is on the ground (tackled player, tackler). At this point the offside lines are created. Players on their feet may use their hands to pick up the ball as long as this is immediate. As soon as an opposition player arrives, no hands can be used.
Rationale: To make the ruck simpler for players and referees.
6. Law 16.4: Other ruck offences
Updated 21:40 - 24 Jul 2017 by Vaughan Evans
A player must not kick the ball out of a ruck. The player can only hook it in a backwards motion.
Rationale: To promote player welfare and to make it consistent with scrum law.