Oakland, California (CNN) -- If college athletes were to start being paid, many schools would leave Division I sports, NCAA President Mark Emmert said Thursday.
And the universities that stayed in Division I sports would have to start cutting other, less popular sports to be able to afford the salaries.
There would be less competition and no more national championship games — at least not in their current form, Emmert said.
Emmert testified at the landmark federal trial for former UCLA player Ed O'Bannon's lawsuit against the National Collegiate Athletic Association. He and other athletes are suing for the opportunity for future athletes to be paid for the use of their names, images and likenesses when they play sports on television.
Emmert said he believes the customs that most college sports fans hold most dear -- the camaraderie of game day, the tailgating, the atmosphere of a stadium packed with nearly 100,000 fans and the pride of cheering for a university team -- are at stake.
"Traditions and keeping them are very important to universities," Emmert said. "These individuals are not professionals. They are representing their universities as part of a university community.
"People come to watch ... because it's college sports, with college athletes," he said.
Those beloved traditions go hand in hand with the model of amateurism, and if amateurism goes away, so will the games as we know them now, he said. Many schools lose money on Division I athletics but keep them for the "social cohesion" and the boost to their profiles, Emmert said.
Emmert said officials at several member schools have told him that if athletes were to start getting paid beyond the cost of attendance, institutions would ditch Division I sports and opt for Division II or III, in which coach's salaries, stadiums, hype and scholarships are much smaller.
"Do the members want the sports to remain amateur?" an NCAA lawyer asked.
"Yes," Emmert replied.
"If the rules were changed to permit student athletes to be paid for (names, images and likenesses), would that change what college sports is all about?
"Yes, it would."
Never before has the NCAA membership — leaders at about 1,100 colleges and universities — proposed changing the rules to allow college athletes to be paid. However, they are currently considering giving athletes a bit more "miscellaneous" money to cover the full cost of attending college.
Emmert, a much-anticipated witness at the three-week trial, testified for five hours Thursday and is expected to continue on Friday.
On the stand, Emmert embodied the NCAA's no-budge, no-compromise take on the issue of pay-for-play, citing the organization's century-old history.
In the five years since the O'Bannon suit was first filed, there have been several controversies and many attempts to reform the NCAA. Emmert acknowledged that public opinion of the organization is low and that part of his directive when he took this job was to fix that.
While he made no concessions to the argument of hypocrisy in college sports — the idea that everyone else involved makes money, except the athletes — Emmert did concede that the commercialization of college sports is overwhelming the amateurism. He said the use of athletes' names, images and likenesses is "one of the most debated topics in NCAA history."
One of O'Bannon's lawyers, Bill Isaacson, displayed picture after picture of athletes with corporate logos and asked, "Putting athletes in front of logos, that's all fine under NCAA rules?"
"It's not something I'm personally comfortable with," Emmert responded. "... It's certainly not where I would prefer the rules be drawn."
Responding to questions from U.S. District Judge Claudia Wilken about commercial exploitation, Emmert said the schools have chosen to define it to mean that college athletes should not be acting as "pitchmen" for products.
A recent poll conducted by the Saint Leo University Polling Institute showed that 66% of Americans don't think athletes should be paid beyond scholarship money.
But complicating the issue are recent academic scandals and consistent court testimony from athletes from several different schools that they were athletes first, not students.
Emmert responded by saying that it's hard to get motivated athletes to focus more on schoolwork, but he insisted that they are motivated to play college sports because of the education they receive.
But when he was asked about that education, he first mentioned the life experience that athletes earn on the field, then discussed what they learn in class.
O'Bannon's lawyers questioned Emmert at length about an e-mail sent to him at the start of his presidency by a senior member of the organization, Wallace Renfro. It said "the notion that athletes are students is the great hypocrisy of intercollegiate athletics" and said the public believes the athletes are exploited in the name of money for higher-caliber coaches and bigger stadiums.
Last week, O'Bannon's lawyers said that even if Wilken were to rule in their favor, the conferences and colleges could still decide on their own not to share any of the television revenues with athletes. As long as the NCAA doesn't have a rule against it, it would still be OK for colleges to choose not to pay.
Rules, Emmert testified, are necessary.
"It's essential there be a body that provides rule-making," he said. "One of the most fundamental principles of fair competition is that everyone is playing by the same rules. Everyone understands they are governing and conducting the game the same way from one side of the country to another. You couldn't do it nationally without those rules."