Three Irish former rugby players - including two internationals - are to sue the IRFU over alleged head injuries.
The latest cases which were launched in the High Court in Dublin are part of a wider series of claims in Ireland and in Britain related to claims of concussion they say they suffered.
Governing body World Rugby has reacted to the action saying that player welfare is its number one priority.
David Corkery and Declan Fitzpatrick who both played for Ireland, and Ben Marshall, who played for Leinster and Connacht, are suing the Irish Rugby Football Union, World Rugby and the provinces they played for.
They're all seeking damages for head injuries they claim they suffered while playing the game.
Their lawsuits are part of over 200 cases being taken in Britain alleging players were not properly protected from concussion.
Solicitor Richard Boardman said: "So whether a player has a concussion or not, every time they tackle, carry, ruck the ball, they are accumulating dings to the head.
"One of those sub-concussions is a relatively mild affair, but over the course of a career, players are accumulating thousands, if not hundreds of thousands of these dings to the head and it's those sub-concussive blows causing dementia, CTE, epilepsy."
In a statement the IRFU said: "As this is a legal matter it would be inappropriate to comment on these cases directly.
"Player welfare is of paramount importance to us and we're constantly reviewing safety protocols for all players.
"Our approach, based on scientific evidence, involves a commitment to ongoing education, monitoring and application of safety protocols across the game, including proactively managing elite player game time with a focus on injury prevention and oversight."
In a statement, World Rugby said: "Player welfare is World Rugby’s number one priority, and we continue to deliver our six-point plan with the aim of establishing our game as the most progressive in the world on player welfare.
"In the last year alone, we have changed the laws of the game, invested millions of euros in research and updated our return to play guidelines following a concussion in the elite game.
"World Rugby will never stand still on player welfare, we continue to review all available scientific evidence and expert opinion, to ensure that rugby is as safe as it possibly can be.
“It is always hard to hear of any former player that is struggling. Everyone who plays our sport is part of the rugby family and that doesn’t stop when people hang up their boots.
“World Rugby has yet to receive details of the claims made against us in the High Court so it is not possible for us to comment on the case at the current time."
It's understood more players are expected to soon come forward to join these legal proceedings, but it's unclear how many across the game in Ireland.