World Rugby is to introduce new penalties for making contact with the head of an opposition player.
All contact, whether accidental or deliberate, will now be punishable as part of a zero-tolerance campaign to limit injuries and "ensure that the head is a no-go area".
World Rugby insists injuries are not on the rise, but the issue has been back in the spotlight recently following claims Northampton's George North played on in a recent match despite being knocked unconscious.
And the revised rules, which come into force at all levels of the sport on January 3, will see all reckless tackles earn at least a yellow card and any accidental contact result in a penalty.
World Rugby is acting on the back of expert research and chairman Bill Beaumont said: "We believe that the invaluable data from this study will inform the law review process and lead to changes in playing or training practices."
Ireland prop Tadhg Furlong said: "When it comes to protecting the head and neck of players, everyone is rightly very cautious now.
"The culture around concussion has completely changed and it's no longer acceptable for players to continue in a game if they're even suspected of having a concussion. When it comes to dealing effectively with concussion in sport, rugby is at the forefront."
The initiative will be supported by a global education programme, while the two new categories of dangerous tackle have been clearly defined.
A player will be guilty of a reckless tackle "if in making contact, the player knew or should have known that there was a risk of making contact with the head of an opponent, but did so anyway."
Accidental tackles cover all inadvertent contact, including "situations where the ball-carrier slips into the tackle".