World Rugby has voted for a change in eligibility laws to allow international rugby players to switch national teams from next year.
From January 1, a player must either be born in the country to which they wish to transfer, or have a parent or grandparent born in that nation, as part of a revised regulation.
The player must also stand down from international rugby for a period of 36 months and may change unions only once, subject to approval by the World Rugby regulations committee.
"Approval of this landmark regulatory change is the culmination of detailed and widespread modelling, and consultation across the game," says World Rugby chairman Bill Beaumont.
"We have listened to our membership and players, and sought to update the regulation recognising the modern professional rugby environment, without compromising the integrity of the international game.
"We believe this is the fairest way to implement progressive change that puts players first, while also having the potential to support a growing, increasingly competitive international men's and women's game."
To represent a second nation under previous rules, a player had to serve three years out of test rugby, hold a passport for their second country and participate in Olympic sevens qualifying to gain eligibility at all levels.
International transfers are currently permitted in rugby sevens to allow players to participate in the Olympics.
The historic rule tweak could help transform the fortunes of tier two test nations, particularly the likes of Samoa, Tonga, and Fiji - both on and off the field.
"It's about having money to reinvest in the grass roots," Pacific Rugby Players Welfare chief executive Daniel Leo told Newshub on Wednesday.
"To have a professional pathway now, you need millions and millions of pounds, so this is a short-term fix towards that."
Former All Blacks back Charles Piutau wants to switch allegiance to his country of birth, Tonga, while ex-All Blacks midfielder Malakai Fekitoa has already completed the process and will be eligible to play for the 'Ikale Tahi' when the new rules take effect next year.
"Great news for all the Pacific Nations," Fekitoa has posted on social media. "Can't wait to get going with the brothers.
"For the people."
Ex-All Blacks first-five Lima Sopoaga - who would now qualify for Samoa - also expressed his delight at the amendment.
On Wednesday, Tonga coach Toutai Kefu said the rule change would have an enormous impact on his team's ability to be competitive against tier one nations and help avoid lopsided results like the 100-point loss to the All Blacks earlier this year.
"I don't think we can consistently beat those teams, but it does make us competitive," said Kefu. "It brings the score from 100 down to 20."
All Blacks star Ardie Savea has also admitted he'd one day love to represent the country of his heritage, Samoa, on the test stage.
"Heart and soul, I still love the All Blacks jersey, and what it's provided to me and my family," Savea said on Wednesday. "But man, the heart and the soul goes back deeper.
"My Samoan blood goes back thousands of years."
Board member Bailey Mackey says the amendment has NZ Rugby's unmitigated support.
"NZ Rugby are big supporters of the rule change, and this also lines up with our support of [new Super Rugby Pacific sides] Moana Pasifika and Drua," Mackey says via social media.
"Having stronger teams in our region has to be a priority. In recent times, we have been proactive in supporting the growth of Pasifika teams."