For more than a century, the only participants in college sports who could not be paid for their efforts were the athletes.

The NCAA has steadfastly insisted that its model of amateurism could not allow players to receive compensation other than scholarships and, only recently, cost-of-attendance stipends.

That changed on Wednesday. The NCAA’s Board of Governors, chaired by Ohio State president Michael V. Drake, announced rules changes that will allow student-athletes to be compensated without limit by third parties for their name, image and likeness (NIL) both related to and separate from athletics.

Schools will still not be permitted to pay its players. Nor can boosters.

But if each of the NCAA’s three divisions adopts the Board of Governors’ recommendation by January, as expected, athletes will be eligible for NIL compensation at the start of the 2021-22 academic year.

That includes the ability to be paid for personal appearances, social media and businesses they have started.

There will be limitations, and many of the details have yet to be resolved.

"It is important that our compliance officers, our faculty reps, our athletic directors and everyone involved in this space contribute to developing the guardrails that we will need around these activities," Ohio State athletic director Gene Smith, co-chair of the NIL working group, said on a Wednesday conference call.

Drake said the rules would include the prohibition of name, image and likeness "that would be considered pay for play" or for recruiting by schools or boosters. They also would include regulation of agents and advisers.

Players would not be allowed to identify themselves by sport or school, and the use of conference or school logos and trademarks would be prohibited.

Still, Drake acknowledged that the NCAA had entered "uncharted territory" by allowing players to derive income without a cap.

It also probably was inevitable. The NCAA has been playing defense after losing some legal and legislative battles, the most significant being an antitrust class action lawsuit brought by former UCLA basketball player Ed O’Bannon.

He successfully argued that his likeness should not have been used in a video game without his permission and compensation. In turn, California passed a law last year that will allow college athletes in the state to profit from NIL, and most other states have followed suit.

"I think they’ve been pushed into the corner here," Andrew Zimbalist, economics professor at Smith College and an expert on the finances of college sports, said of the NCAA.

"They know they have to do at least what this report is saying. They’re lobbying in Congress to get a bill that enables them to control this process best. What they’re doing now is letting the air out of the tire so the tire doesn’t explode."

Zimbalist has been critical of the NCAA’s amateur model, and he said that parts of the organization’s recommendation were "incomplete and unrealistic."

For example, he took issue with the NCAA’s position that group licenses, which could allow the return of the popular NCAA college football video game, were unworkable because of the absence of a recognized bargaining agent on behalf of players.

But he praised the NCAA’s change in philosophy as "a significant first step."

As for the amount a player could expect from NIL, Zimbalist said it was difficult to predict. For the average athlete, he said, income would be modest. But at the top for a star at the level of Ohio State quarterback Justin Fields, it could be quite lucrative.

"I think you can easily imagine tens of thousands of dollars, and perhaps even six figures," Zimbalist said.

Among the difficult issues the NCAA must grapple with will be the lack of an income gap. Smith said NIL compensation must include the disclosure of activities and compensation, and that the amount of payment cannot be "abnormal" for the services provided. For example, a five-figure payment for a couple of endorsing tweets about a business would raise a red flag.

"There will be some subjectivity there because that’s the market," Smith said. "But the reality is reasonable, rational and prudent review of that activity will hopefully allow us to determine if it's appropriate."

Smith said athletes will have to pay taxes on their NIL income, and added that the amount could affect their scholarship or Pell Grant if they have that.

That’s probably an offset most players would take.

"I definitely think it’s a good idea," former Ohio State safety Jordan Fuller said at the NFL combine in February when asked about the pending NIL proposal. "Honestly, I don’t think it’s hurting anybody if guys can get paid for their name, image and likeness. I think it’s making everything better.

"Right now, we’re playing for free. We might as well be able to make some money off the field as college players. So I think it’s great."

The NCAA is seeking legislation from Congress to ensure federal guidelines instead of patchwork ones established by individual states. NCAA president Mark Emmert said he knows that won’t be easy, especially now.

"There’s no question that passing a bill in Congress under the best of circumstances is a hard thing to do these days," Emmert said. "With a pandemic going on and an election going on, that makes it that much more challenging. Everybody’s realistic about those difficulties.

"Nonetheless, the goals that are written into this report the working group brought forward are very consistent with the values of intercollegiate athletics. Our early conversations with members of Congress … suggest that they’re not anathema to what Congress might want to do."