Rugby Australia have announced new guidelines the will see eight- to -15-year-old players whose weight or height falls outside the average range assessed to determine the grade they compete in.
The world-leading new "size-for-age" system will now also take into account a player's fitness, experience and maturity, drawing on two years of research with the Australian Catholic University, the Sydney Junior Rugby Union and Brumbies juniors.
Rugby Australia stressed that while the game requires a number of shapes and sizes, the study had determined that weight alone is not a strong enough factor to categorise players.
"We're looking for kids that are a long way away from the averages, both below and above, then we take in the other factors and a decision is made to move or not based on the recommendations of the coach," rugby services head Lachlan Clark said.
"Rugby is a game for all shapes and sizes and we don't want to knock that out of the game. We need props, locks and halfbacks.
"But we want to create an environment where players of similar physical development, skills, experience and maturity are playing together.
"That's when rugby is the most fun, it's where you get the best skill development and it's where it's the safest, so kids will want to keep playing."
While similar national guidelines exist already, the move will now make it mandatory to make a call in the under-10s and under-15s competitions for the first time.
It comes the same week as Russell Crowe, a staunch supporter of weight-based competitions, called on rugby league to introduce a "weight-for-age" system, something Triple M's Mark Geyer agrees with.
"There's got to be a competition to run adjacent where there's an option for kids," he said on The Rush Hour with MG. "I think the time has come. Rugby league junior numbers have declined.
"I get what Russell is saying about it. I'm sick of seeing in junior games one bloke getting the ball and running and scoring."
Have a listen to MG's weight v age debate below:
You can hear The Rush Hour with MG weekdays from 6pm on Triple M 104.9 or on the Triple M app.