Players making contact with an opponent’s head in “reckless tackles” will receive a yellow card at least in changes to rules over high tackles.
Players will be punished even if the tackle starts below the shoulders.
If head contact is accidental – for example, if a ball-carrier slips into a tackle – a penalty will be awarded.
World Rugby says the new rules, which come into effect on 3 January, “aim to change culture in the sport to ensure that the head is a no-go area”.
A reckless tackle occurs when a player “knew or should have known that there was a risk of making contact with the head of an opponent, but did so anyway”.
In September 2015, World Rugby’s chief medical officer Martin Raftery told the BBC that the game’s rules may have to change to reduce concussions.