A federal judge has ruled that some college athletes can receive payments when they leave school for the rights to their names, images and likenesses, opening the door for them to get a fraction of the billions of dollars generated by collegiate athletics. The decision comes after a lawsuit launched by former UCLA basketball star Ed O'Bannon, who was upset because his image was used in a video game, but he wasn't paid.

Here's a few key questions to understand Friday's ruling:

Q: What does this ruling mean?

A: It opens the door for football and men's basketball players to get money once they leave school. But they likely won't be in for huge windfalls, at least the way U.S. District Judge Claudia Wilken envisions it. She said the NCAA can cap payments made to players for their names, images and likenesses, as long as that cap isn't less than $5,000 a year. That would mean players on a roster for four years could potentially expect some $20,000 when they leave school.

Q: Where does the money come from?

A: The money would be taken from the billions of dollars flowing into major college athletics and schools would put it in trust funds that would be given to players only when they leave school. Individual schools could pay less than $5,000 if they want, but Wilken said they can't unlawfully conspire among themselves to fix a certain amount to pay.

Q: How will the money be paid?

A: That's anyone's guess. Lawyers for the plaintiffs have set up a company to negotiate rights and dole out payments, or the schools themselves could do it. It's really uncharted territory and no one knows exactly how it will play out.

Q: Do swimmers or tennis players get the same money?

A: No, this lawsuit was limited to football players in FBS schools and Division I basketball players.

Q: What else can these players get? Can they endorse sports drinks or shoes now?

A: No. Wilken ruled that all other NCAA regulations concerning extra pay, endorsements and other benefits will remain in effect. She also said the NCAA could also enact new legislation designed to prohibit players from using the promise of funds received when they leave school to get other money while in school.

Q: Is this just the beginning of wholesale changes in college athletics?

A: Not necessarily, though in shutting down the NCAA's amateurism defense, Wilken may have opened the door for other challenges to the organization's authority. She said in her ruling that any other changes in NCAA regulations should not be addressed in antitrust court cases but by schools, conferences and even Congress. Most observers believe the O'Bannon lawsuit and related union organizing efforts at Northwestern were the driving force behind the biggest five conferences this week moving to expand benefits they give their players.

Q: When will recruits be offered this extra money?

A: Not for a while. Wilken said it will not affect any prospective student-athlete who enrolls in college before July 1, 2016.

Q: Will the NCAA appeal?

A: Almost certainly. NCAA lawyers said earlier the issues are so important they will go all the way to the Supreme Court if necessary.