In this tense city where a campaign called "Talking Proud" has been launched to rid citizens of an inferiority complex, the Buffalo Bills have become a rallying point as the only unbeaten team in the National Football League.

Ever since O.J. Simpson voiced a reluctance to leave his native California to play here after being drafted by the Bills, Buffalo has been the butt of jokes about the weather and other deficiencies in charm.

Poking fun at themselves, some professional exploiters annually celebrate the "blizzard of 1977" by hiring a ballroom, selling T-shirts and dancing and drinking to the memory that begot the commentary from an outlander that "People in Buffalo lock the front door on Oct. 15, when the first snow falls, and don't come out until April 15."

Coach Sam Rutigliano of Cleveland said, "Buffalo is not the end of the world, but you can see it from there."

But after two incidents Thursday, coming here for a pro football game is reminiscent of going to Dallas to watch the Cowboys after the assassination of President Kennedy.

For the second straight day a cab driver was found murdered, with his heart cut out. The community was already numbed by four execution-style gunslayings within a 36-hour period less than three weeks ago. On Thursday night, a cross was burned in the predominantly black East Side. All the murder victims were black males.

Geographically and culturally distant as Buffalo is from Paris, both cities are similarly alarmed about signs of bigotry: in France, anti-Semitism; in Buffalo, racism. Witnesses to the four shootings here said the gunmen were white. Black leaders urged police to investigate what they call a conspiracy against blacks.

Adding to problems here is an unemployment rate of about 10 percent in steel manufacturing and automobile assembling.

Because Rich Stadium seats 80,020, because the Bills had been in a slump until last year, and because the weather is a deterrent at the end of the season, only 21,000 season tickets were sold.

Yet, two of the first three home games have been sold out, and a third sellout is possible Sunday for the visit of the Baltimore Colts.

The attitude is akin to President Roosevelt's decision during World War II to allow baseball to continue, "because . . . people cannot be expected to wring their hands in apprehension 24 hours a day every day," as one commentator put it.

Guard Reggie McKenzie of the Bills, in his ninth season, was asked why he keeps playing in view of the Bills' four losing seasons since the 8-6 record of 1975.

"I'd like us to treat the fans to a Super Bowl," he said. "They would go insane. It takes 59,000 of them buying single-game tickets to fill the stadium with only 21,000 season ticket holders. But they do it. They were 5,000 of them waiting for us at the airport after we got back from beating the Chargers on Sunday in San Diego -- at 2 a.m.!"

Isiah (Butch) Robertson, the one-time rebellious linebacker and playboy of the Los Angeles Rams, is building a home here.

He missed the trash receptacle on the practice field with his toss of a paper cup and was reminded that former Ram Coach George Allen disciplined him for just that, causing a front office upheaval that resulted in Allen's dismissal.

Robertson ridiculed the memory of Allen, and then said, "No, thank him for me being here."

How did Robertson find happiness in Buffalo, of all places.?

"With a 5-0 record," he said.

Coach Chuck Knox was asked how he managed to keep players as outspoken as Robertson and guard Conrad Dobler contented.

"They have become leaders here," Knox said. "Dobler is a throwback to the past. He has knees so sore others wouldn't play with such injuries, but he goes out there and shows the youngsters how. Robertson relishes his role here, and he was so much a part of that Hollywood scene."

Joe Cribbs, the second-round draft choice from Auburn, already has replaced Terry Miller as the "big name" of the Bills, though Miller was a 1,060-yard rusher in 1978.

Cribbs is the leading ground gainer in the American Conference, with 376 yards, the leading scorer with seven touchdowns, six on the ground, and has 22 receptions, although he caught only 30 passes in his four seasons in college. He also returns punts for the Bills since they told him Gale Sayers did, too.

"I wondered," Cribbs said, "after I watched the draft on television and saw I didn't get picked on the first round. I thought the Redskins were going to take me on the first round. Of all the teams that talked to me before the draft, they convinced me that they were the most interested. They said they were going to take me.

"Bobby Beathard (general manager) and Mike Allman (personnel director) came down to visit me before the draft. I was timed for 40 yards (4.5 seconds). They tossed passes to me. They gave me a weight lifting program before the draft and I gained four pounds in about a month, from 186 to 190. I don't think it matters that I am small (5-foot-9) with the new rules of the last couple years, and my speed.

"There is more room to run on both sides of the field since they moved the hash marks closer to the center. I can get loose on pass patterns now that the defenders can only have one bump at you within five yards of the line of scrimmage. I always knew I could catch the ball. I never heard from the Redskins after the draft."

The Redskins passed up Heisman Trophy winner Charles White because of his size (5-9, 186) and lack of speed.

The acquisition of Cribbs amounts to the last draft choice payment to Knox for trading Simpson to San Francisco.

At first, Cribbs said he dreaded Buffalo winters, but though he doesn't like to be compared with Simpson otherwise, he said, "If O.J. could handle it as a Californian, I can. I am going to move here and get married in the off-season and my girlfriend is from Pensacola, Fla."

He majored in criminal justice at Auburn and said he is going to go back for 12 hours of credits he needs for his degree. "I have to have something to do or I might get into trouble," he said jesting. "I am an organized person. I may go for my master's degree.

"I don't know how long this (football) will last. I see so many players who can't do anything else after football. $"I got interested in criminal justice while trying to help 15-to 18-year-olds in a correctional facility, as part of my studies. The chief of our five-person team wasn't getting through at all to the youngsters. I and another football player did and I think it was because they looked up to us."

He talked about the Seattle Seahawks, one of the few NFL teams that give bonuses to draftees who go back to college for degrees and incentive clauses to rookies to finish education interrupted by college football. "I'd like to see more of that," he said.

Cribbs could prove a welcome diversion for this troubled lunch pail community. Football has its rewards here; Rep. Jack Kemp, former Bills player, made a compact with Erie County voters, threatening, "If you don't elect me to Congress, I'll make a comeback as the Bills quarterback." He was elected.