A 1973 graduate of Granite Hills High School in El Cajon, Roth led Grossmont College of El Cajon to an undefeated season and state title in 1974, and transferred to University of California, Berkeley in 1975.
Originally a back-up, he started the fourth game of the 1975 season, and led the California Golden Bears to the Pac-8 title as co-champions. Cal led the nation in total offense, gaining the same yardage both passing and rushing with 2,522 yards each.
In 1976, Roth was a pre-season favorite for the Heisman Trophy. The season was more tumultuous, and towards the end of the year Roth's performance started to drop, but he was named an All-American and finished ninth in the Heisman Trophy voting.
After the season ended, he revealed that halfway through the season he had been diagnosed with terminal melanoma – apparently the metastasis of a mole that had been removed from his face several years earlier. Despite his deteriorating physical condition, he honored his commitments to play in both the Hula Bowl and the Japan Bowl. According to a friend's reminiscence, during the Japan Bowl festivities Roth had agreed to sit for a thirty-minute autograph session; but finding, at the end of the scheduled time, hundreds of children still waiting, he continued to sign until every child had an autograph, after which he left the building and vomited.
By mid-February he was in the hospital, where (in the words of the San Francisco Chronicle)