The NCAA and helmet maker Riddell are defendants in separate class-action lawsuits alleging they failed to protect football players from long-term head injuries and didn't educate them about the risks.
The Fort Worth firm of Circelli, Walter & Young filed the lawsuits Monday in federal courts in Indianapolis and San Francisco.
The lawsuits ask for damages for health care costs, lost wages and other personal injury damages.
The Big 12 Conference was listed as co-defendant with the NCAA. Named plaintiffs are former players Cory Brandon (Oklahoma), Kelvin Chaisson (Oklahoma), Derrick Cherry (Texas Tech), Jarrod Blake Roberts (TCU) and Joe Walker (Texas).
The Riddell lawsuit alleges the helmet maker misrepresented the safety of its helmets.
Circelli, Walter & Young said all plaintiffs in the cases suffer from some degree of traumatic brain injuries from multiple concussions or serious jolts to the head that don't meet the diagnosis of concussion and all were incurred while playing football.
The NCAA, Big 12 and Riddell did not immediately respond to requests for comment Tuesday.
Heather Hughston, a spokeswoman for Circelli, Walter & Young, said the firm plans to file additional lawsuits naming other college sports conferences as defendants.
Last year the Chicago-based law firm Edelson PC filed more than 40 class-action lawsuits against the NCAA related to the handling of concussions by Division I football programs. Those complaints also named college conferences and, in some cases, schools.
A judge in a previous case ruled one large class-action concussion lawsuit could not be filed against the NCAA.
In the lawsuit filed against the NCAA this week, former football players allege that the governing body for college sports and the Big 12 "breached their duty to provide a 'safe environment' and specifically failed to warn players of the long-term risks associated with repeated concussive and sub-concussive hits."
The lawsuit also accuses the NCAA of "failing to educate players on head injury prevention, failing to timely implement rules of play that would limit head injuries, failing to timely implement return to play rules after concussions occurred, and failing to cover the cost of post-collegiate medical care necessary as a result of the defendants' bad acts."
The Riddell lawsuit includes former high school and college football players. It alleges the helmet maker, in its marketing, claimed a scientific study showed its helmets significantly reduced the risk of concussions compared to other manufacturers' helmets. The lawsuit said that study was funded by Riddell and that the helmet maker has been the focus of ongoing litigation as a result of its claims.