A legal claim against the Rugby Football League for negligence is to be launched this week, lawyers acting for 75 former players have said.
They say the RFL did not “take reasonable steps to protect players from permanent brain damage caused by repeated concussive and subconcussive impacts”.
The announcement comes with the Rugby League World Cup kicking off on October 9.
Corresponding action was initiated by rugby union players the summer.
The RFL says it is “extremely sad” to hear of the players’ problems and stressed it takes player welfare “extremely seriously”.
He added that “continues to improve and develop its approach to protecting players’ physical health and provides support to former players.
Former Great Britain scrum-half Bobby Goulding, along with 10 other former rugby league players, have previously claimed the sport has caused them brain damage.
Goulding has been diagnosed with early-onset dementia and said there was insufficient protection for players who had suffered head injuries.
The legal firm representing professional and semi-professional rugby league players says it will serve a letter of claim against the RFL this week.
What do players claim?
Lawyers for the players said many “now suffer from a variety of irreversible neurological damage, including dementia, CTE (chronic traumatic encephalopathy), post-concussion syndrome, epilepsy, Parkinson’s disease and motor neuron disease.”
They have made 53 allegations against the RFL, including failing to “ensure that a suitably qualified person was responsible for the treatment of head injuries within the sport and the systems, protocols and enforcement associated with it”.
They also claim that the organization “failed to respond to changes in the intensity and physicality of the rugby league game during the 1980s and 1990s by adapting rules, protocols, coaching, refereeing or nothing at all”.
“We are seeing the same worrying symptoms in many cases across both rugby codes,” said Richard Boardman of Rylands Legal.
“These symptoms include chronic depression, aggression, significant memory loss, incontinence, drug and alcohol addiction and, in some cases, suicide attempts.
“This claim is not only about financial compensation, but also to make the game safer and to ensure that current and former players are tested so that if they suffer brain damage, they get the clinical help they need.
“The players we represent love the game. Our aim is to challenge the current perceptions of governing bodies, to get them to a point where they accept the link between repetitive head impacts and permanent neurological injury, and to take action to protect players and support for those who are injured”.
What does the RFL say?
The RFL said it “takes the safety and welfare of players extremely seriously and was desperately sorry to hear of any difficulties experienced by players” in a statement to BBC Sport.
“Rugby League is a contact sport and while there is an element of risk involved in playing any sport, the welfare of the players is always of the utmost importance,” he added.
“As a result of scientific knowledge, the sport of rugby continues to refine and develop its approach to concussion, head injury assessment, training, management and prevention throughout the game.
“We will continue to use medical evidence and research to strengthen and refine our approach.
“Support for ex-professional players is always available from rugby’s charity partner RL Cares.”