New Zealand Rugby is cracking down on concussion, introducing a new blue card initiative across all adult rugby games in its 14 largest provincial unions.
Referees who suspect a player has been concussed during a game will issue a blue card.
The player must leave the field and can't return until they have completed a series of mandatory steps, including a three-week stand down from training and playing.
NZR's head of community rugby, Brent Anderson said referees would be trained to recognise the signs of suspected concussion.
The initiative sent a clear message about the importance of looking after players on and off the field, he added.
"Player welfare is everybody's responsibility," Anderson said.
"While head knocks are relatively rare given the number of matches every weekend, it's important everybody understands how to manage concussion.
"We need to ensure players don't return to play until they are medically cleared and ready."
It's the first time the concussion initiative has become compulsory for adult grades, and Anderson said NZR would eventually like to see it as the standard for the community game.
The initiative originated in Northland Rugby in 2014, with the positive feedback from the rugby community encouraging NZR to extend it.
"We're very pleased at the response from our communities so far," Anderson said.
"People understand what we're trying to do and why it's important to put our players' health first."