A lobby group composed of players, officials, referees, coaches, medical experts and teachers has been formed to campaign for improved safety in the sport they describe as "broken".
Spearheading Progressive Rugby are former internationals, including Canadian Jamie Cudmore, who is involved in a long-running legal dispute with his former club Clermont Auvergne, and England forward James Haskell.
Cudmore has said the French club "put my life in danger" for effectively forcing him to play when concussed.
The group has made radical recommendations, including the removal of tactical substitutions, aimed at reducing incidences of concussion.
In December nine former professional players in their 30s and 40s, most diagnosed with early-onset dementia, launched legal proceedings against World Rugby and other governing bodies.
Former internationals Steve Thompson of England and Alix Popham of Wales, who are leading that case, are also members of the group.
"Progressive Rugby passionately supports the core physicality of an 80-minute game of rugby and that extends to tackling in schoolboy rugby," the organisation said in a news release.
"However, Progressive Rugby believes that, around the acceptable risks that come from a game, much more can be done to protect current players and future generations."
Among the experts is Ireland's Dr Barry O'Driscoll who stood down from what was then called the International Rugby Board in 2012 in protest against its handling of concussion cases.
"We all love rugby and want to see it continue in the long term. However, the game as it is, is broken, with many more players likely to end up with neurological impairments in the future," O'Driscoll told a news conference on Wednesday.
"The IRB's treatment of concussion was going badly wrong then and has got worse since - it is a dereliction of duty."
Progressive Rugby sent an open letter to World Rugby chairman Bill Beaumont demanding that more should be done to protect the rugby-playing community from the dangers of injury.
"World Rugby has a moral and legal duty to minimise risk and to inform players and parents of the risk of brain damage from repeated knocks," the letter added.
This was in response to a letter Beaumont, the former England captain who had to retire early after suffering multiple concussions, published last December which said that "player welfare is – and always has been – our number one priority at all levels of the game".
Progressive Rugby says it "firmly supports the core physicality that comes with the game" but that its proposed changes "are essential to ensure its survival in terms of long-term player welfare and playing numbers at all levels".
Coming days after the Rugby Players' Association held its first "brain health webinar" for former players, the new group is calling for major cutbacks on contact and workload in training, the limitation of replacements to injury only, strict application of laws at the ruck and a review of the tackle area.
The group also calls for a minimum three-week "return to play" protocol period after a concussion and mandatory comprehensive screening.
Progressive Rugby points to American football's NFL, which has paid out almost one billion dollars in concussion settlements, as having "metamorphosed from a sport in denial to a proactive organisation" and wants World Rugby to follow its example.
"Clearly these members of our rugby family love the game and want it to be the best it can be," World Rugby said. "We do too. We are encouraged that the group are championing a number of initiatives that are already operational or being considered and we are open to constructive discussions with them regarding their proposals."