For years the writers of NBC's "Saturday Night Live" have sallied forth to tilt with the windmill of network censorship. Now the battle seems to have reached a turning point. The windmill is winning.

"It used to be more of a fight," says producer Lorne Michaels. "Now it's just a flat 'no.' " Michaels, who produced the first five seasons of the show, and the past two, says many of the sketches done during the satirical program's heyday in the late '70s would never get past network censors now. At least one network censor agrees.

"Saturday Night Live" returns for its 13th season on Oct. 17, with last year's cast intact. Steve Martin will host the first show; it will be announced in New York today that Sean Penn, actor and pugilist, has also been signed to host one edition this season. Michaels says he hopes to get Democratic and Republican presidential candidates to appear: "The only ones we haven't heard from are the Bush people."

Michaels also anticipates another year of increased conservatism by NBC censors, with whom he has been losing more battles than he'd like.

"There isn't a week in which four or five things aren't suggested that we think would be funny, and the best thing on that subject, and we can't do them," says Michaels from New York.

"Saturday Night Live" made its reputation with humor proudly considered too wild for prime time. NBC's office of Standards and Practices tussled with the writers from the start. But the program bent rules and broke new ground, and coaxed millions of baby boomers back to their television sets.

As to why NBC is imposing new, stricter censorship on his program, Michaels says, "I don't think it's the mood of the country, or the presidency, or anything like that." It's more a result of the changing economics of networks.

"In the old days, when NBC was the third-place network and we were a hit, we were given a little more freedom," Michaels says. "Now, there's really only enough of an advertising base to support 2 1/2 networks, so they're much more mindful of sponsors, and Standards is much more wary. Things I could do to make the show more successful would also make it more controversial, and the network does not want a controversial show."

It isn't just that sketches are nixed at the script stage, as was long the practice. Network censors took a new approach last season. Comedy approved in advance and broadcast live was then banned after the fact. Two of last season's shows were not rerun this summer because the censor demanded sketches be cut from them, and Michaels refused to make the deletions.

One such skit, on a show hosted by Steve Guttenberg, was about a homosexual attempting to seduce a blind man. Censors wanted it removed from the rerun even though it had already aired with their approval. They also demanded that a sketch called "What's My Addiction?," featured on a show hosted by Paul Shaffer, be removed before the show could air again.

Richard Gitter, the NBC censor (he prefers "editor") assigned to "Saturday Night Live," says the blind man skit gave him "enormous concern and trepidation" and that even though "it was played very sweetly and it seemed rather funny" when rehearsed, "it did not play as well on the air as it did in Lorne's office."

He says the segment offended "the gay community" and "the handicapped." Were there angry letters after it aired? "Not an enormous amount," Gitter concedes.

As for "Addiction," Gitter says that at the script stage, the spoof seemed to dramatize "the ravages of addiction," as well as the varieties of it, "but that kind of theme is very difficult to get across within a humorous context. It's too easy to laugh and lose the message."

So when the studio audience laughed, Gitter had another attack of second thoughts. Michaels, exasperated, says, "If something gets big laughs, they think it's even more reason to take it out of the show." Gitter says, "That's a misperception on Lorne's part. Humor is the mitigating factor. If something really gets a big laugh, if it's truly funny, that mitigates the offensiveness."

Thus, it could be said, the censor puts himself in the role not only of judging what's fit, but also of judging what's funny.

Gitter acknowledges that on some points, the censor will not listen to argument. Humor involving drugs is one such area. Former NBC chairman Grant Tinker laid down a strict edict on drug jokes while at the network; Tinker never liked "Saturday Night Live" anyway. The rule has remained in effect under NBC President Robert C. Wright, the man General Electric installed in the job.

"We may have been guilty of some negligence early on, but we have learned," says Gitter, referring to earlier days of "SNL" when drug jokes were fairly common. "We just do not want to be part of that anymore. Drug material is one area where discussion would not be useful, just a waste of time."

One of "SNL's" most brilliant founding stars, John Belushi, died of a drug overdose in 1982. Drug problems were rampant among writers and performers in the show's wonder years. But Michaels thinks that to pretend now that drugs and drug abuse do not exist restricts the show's ability to comment on facts of modern life. "I'm unhappy that they presuppose that if we do drug humor, it will be pro-drugs," he says. "People are uncomfortable with laughter at a serious subject. They get worried about it."

Michaels says there were many other problems with the censor last season. Sometimes lines spoken during the live broadcast were deleted on censor's orders when the show aired later, on tape, in western time zones.

One such line occurred in a sketch starring Bill Murray as singer Nick Slammer, appearing before inmates at a minimum security prison. Nick chatted with prisoners, one of whom rose to identify himself and then, with an arm around a man next to him, said, "and this is my bitch, Ivan Boesky." Censors trimmed it from the West Coast version and wanted it cut from the rerun.

All season long, Michaels tried to get a sketch called "Dog Confessional" approved. Written by Al Franken, it depicted a series of dogs, played by cast members, confessing to a priest. Gitter says it would have offended Catholics. Even an intercession by NBC Entertainment President Brandon Tartikoff couldn't get it through the censor's net.

Gitter denies that Wright or other executives have called for the deletions. "Never," he says. "Bob's concern is that the show be funny and endearing to viewers, and get good ratings."

Ratings for "Saturday Night Live" inched up 4 percent last season over the previous year, but Michaels thinks the show is hampered by the heavy censoring. "Movie comedy and cable comedy both have much greater freedom," Michaels says. "SNL" blazed trails, yet now doesn't enjoy all the freedoms it helped secure.

"After 13 years, people know that if they're not interested in the kind of thing we do, they should not be watching us," Michaels says. "We should be allowed to kick ass. That's what our mandate was. Lots of things that are funny are at people's expense."

The censor isn't Michaels' only worry. NBC's "Late Night With David Letterman" gets more attention than "SNL" these days. Asked if he is angered when he hears that "Late Night" has assumed the cutting edge once owned by his program, Michaels says, "No, because I was the guy who said it, mostly. I'm a fan of that show. They're doing everything they can to keep every second of that show interesting."

(Michaels made that remark prior to last week's big Letterman slump. Like "Saturday Night Live," Letterman and his crew have shown a knack for bouncing back).

"We're a different style. We're presentational," Michaels says. "They're allowed to comment on what they do as they're doing it -- to do jokes about not doing jokes. We have to take the full swing at the ball, you might say. Our show is much, much more about writing."

If "SNL" has risen to respectable ratings after several years of humiliation (having peaked during Michaels' first term as producer, 1975-80), it still suffers the ignominy of getting bested once a month by 90-minute wrestling shows that air in its time period on NBC.

"I think it is a function of the syndication," Michaels says. "Each independent station promotes the wrestling thing in their market. If it was on the network every week, it probably would get a different number. My cross to bear is that wrestling is in my time period. The sales department is very happy with it."

One might think NBC would be embarrassed to put wrestling on a network after years of its being banished to local stations, but there's nothing like advertising revenue to cure network embarrassment.

Michaels' other wrestling match, with network censors, goes on.

Gitter, for his part, says Standards and Practices serves as "quality control for the network, for the service that we provide our viewers," and that "if we see a shoddy product put out, it would be silly to say, 'Let's continue the product' when we have an opportunity to correct the situation.

"We are not going to befoul the airwaves with inappropriate language," Gitter says. Spoken like a true censor. Michaels strikes a conciliatory note: "I'm not at war with them, because they are trying harder," he says. If it isn't war, it's not peace, either. But then peace has never been a part or even a parcel of "Saturday Night Live."