George Mikan, the bespectacled giant who so dominated pro basketball in its early years that the game was forced to change its rules, died of kidney failure June 1 at a rehabilitation hospital in Scottsdale, Ariz. He was 80.

One of his legs was amputated in 2000, and he recently was hospitalized for treatment of a diabetes wound in the other leg, the Associated Press reported.

The 6-foot 10-inch, 245-pound center was the sport's first superstar. Inducted into the National Basketball Association Hall of Fame in 1959, Mr. Mikan was voted the game's greatest player in the first half of the 20th century and was named one of the 50 greatest players in NBA history in 1996.

"He was a guy who changed the game," said Matt Zeysing, historian and archivist at the Basketball Hall of Fame in Springfield, Mass. "He was agile getting up and down the floor. Most centers at that time were lumbering, and . . . not necessarily as aggressive as he was. He was the intimidator. He was the guy taking the contact."

His size, his history of personal fouls (he led the league three times), his 10 broken bones and 166 stitches during his career caused some to call him a rough player. He was certainly a tough player, powering through the 1950 playoffs with a broken wrist and the 1951 playoffs with a fractured leg.

"I played all right, scored in the 20s. I couldn't run, sort of hopped down the court," he told Newsday in 1990. Sporting thick eyeglasses and well-worn kneepads, he was "a basketball tractor, powerful and steady," another writer said.

He invariably would sink his sweeping hook shot, whether using with his right or left hand. His old-fashioned two-handed set shot was also deadly. He could dunk, which he did in practice but not during a game because it was considered ungentlemanly.

Mr. Mikan led the Minneapolis Lakers to five championships and led the pros in scoring six times. He averaged 22.6 points per game in his career, when game scores were much lower than they are today. In the 1948-49 season, he averaged 28.3 points and was the league's most valuable player.

Mr. Mikan played the low post, close to the basket, and was an inside shooter, much like another former Lakers player, Shaquille O'Neal. The rulemaking National Basketball Committee widened the foul lane from six to 12 feet to make it more difficult for Mr. Mikan and players like him to score. But it seemed to have little effect.

He also could play defense. As college athletes, he and fellow big man Bob Kurland swatted away so many opponents' shots while they were above the hoop that the rulemakers banned the previously unheard-of goaltending. The pros didn't keep rebounding records until 1950, and when those began, Mr. Mikan led the league twice.

Mr. Mikan was an immensely popular player when the sport attracted only a few thousand fans to each game. He was one of the first basketball players on the Wheaties "breakfast of champions" cereal box, and on a December night in 1949, the marquee at Madison Square Garden overlooked the rest of the Lakers to tout "Geo. Mikan vs. Knicks."

He was so dominant that in 1950, the Fort Wayne Pistons decided the only way to win was to hold on to the ball. They won 19-18, in the lowest-scoring professional game in history. A few years later, a rule required each team to shoot within 24 seconds of getting possession of the ball.

Born into a Croatian family that ran a bar and restaurant in the prison-and-steel town of Joliet, Ill., Mr. Mikan grew to well over 6 feet tall by the time he was 11. His only early sports achievement was winning the Will County marble-shooting championship.

He was cut from his high school basketball team in 1937, after the coach realized that his nearsighted player could not see without thick glasses. A short time later, on a playground, he stepped on a basketball and broke his leg, the first of many fractures. Unable to walk normally for a year, he entered Quigley Preparatory Seminary in Chicago, intending to enter the priesthood.

The legendary DePaul University coach Ray Meyer, on a hunch, gave the tall, awkward student an athletic scholarship and taught him conditioning, discipline and the game. One drill that beginning players still use is named after Mr. Mikan.

Meyer's hunch paid off: DePaul won the National Invitational Tournament title in 1945, and Mr. Mikan was a three-time all-American and two-time college player of the year.

Mr. Mikan started out in the pros making an unheard-of $12,000 with the Chicago American Gears. By 1950, as the highest-paid player in the game, he made $25,000. Mr. Mikan, in retirement, got an NBA pension of $1,700 a month, and in recent years, he urged that the league increase pensions for its pre-1965 alumni.

Mr. Mikan announced his retirement after the 1953-54 season, after numerous injuries: broken legs, feet, wrists, fingers, nose and kneecap. He had a permanent limp and could not fully straighten his arms. He said he wanted to spend more time with his wife, Patricia, and their four sons and two daughters.

He staged a temporary comeback in 1955-56, but his skills had atrophied. He coached the Lakers for part of the 1957-58 season and then became a lawyer in the Minneapolis area.

In 1967, he returned to the game as commissioner of the fledgling American Basketball Association, introducing the red-white-and-blue ball. After two years, he left the game again until the mid-1980s, when he lobbied for an NBA franchise for the Twin Cities, to replace the long-departed Lakers. That team arrived for the 1989-90 season as the Minnesota Timberwolves. In 1993, he became the owner of the Chicago Cheetahs roller-hockey team, which lasted two seasons.

He expressed only one regret about the evolution of the basketball game: Players lack the passing skills of his era, when "going upcourt, the ball wouldn't hit the floor."

George Mikan grabs a rebound in front of Minneapolis Lakers teammate Herman Schaefer. Mikan led the Lakers to five NBA championships.