The Herald spoke to five rugby people on what the changes might mean for the game in 2017.
Those immersed in professional rugby are mostly just getting on with it, seeking ways to adapt to the new landscape.
These laws will not be changing. They are enshrined, which is within World Rugby's remit on player welfare.
But there are sceptics and there will be teething issues, as evidenced by last weekend's play in Europe, where there is often a chasm between fact and interpretation when differentiating on a reckless or accidental tackle.
"We agree 100 per cent that safety is paramount in the game. With the increase in medical science and understanding the consequences of contact to the head, we are supportive of that. I think there are going to be interesting interpretations of how that might look, particularly when you get very close to the line, and guys are driving low. It's going to be interesting, but we just have to adjust to whatever the ruling, just like we did with the trial [laws] in the Mitre 10 Cup."
Rod Hill (NZ Rugby referees boss)
"It's not going to be easy to get it right through all the grades, but we want mums and dads to have their kids playing the game. If we work together, we'll achieve the goal. If we push against it, then you are looking at the game from the wrong perspective. Our challenge as refs is to achieve consistency across the group.
There is a judgmental element as to what is a reckless tackle and what is an accidental tackle. That will make the refs' jobs a bit tougher but at the end of the day, a swinging arm to the jaw equals a red card."
Stephen Kara (Head of New Zealand Sports Medicine Practitioners and Blues doctor)
Stephen Kara
"It's a positive change. We've had the recognise, remove, recover and diagnose type scenario. This is the next phase, an injury prevention strategy. Studies out of the UK show most concussions occur out of the tackle situation, about 30 per cent being the person tackled, and the rest the tackler. Now you can't take the tackle out of the game. That's not what we want to do. But by lowering the tackle, it might just reduce the risk to the person being tackled. It's a tough sport and the contact has ramped up. It's very much a defence-oriented game. This is positive without changing the nature of the game."
Allan Pollock (North Harbour sevens coach)
"I have always been a big fan of training my defence to tackle below the ball. Part of being in a good position to make a tackle is lowering your shoulders and you must leave your feet. If you do all that, you won't have these standing tackles where you are getting shoulder on chin. It does come back to coaching. We have coached a generation to 'big bang' on tackles. That was not the way 20 years ago. Coaching has brought us to that point, and coaching has brought us away from that point."
Isa Nacewa (Leinster outside back)
"We haven't trained any differently. To us, the laws around head-high tackles haven't changed to what was in place around the 2015 World Cup, more so just how it is enforced. What has changed is the awareness of it has been heightened. And how the referee sees it and enforces it. We have just focused on getting on with it."
