Despite 15 years of camping it up on "All My Children" as deliciously bitchy Erica Kane, Susan Lucci is a picture of studied graciousness as she sits regally on the edge of a couch in the ABC studios where the highly rated soap is taped. But the icy composure begins to defrost when she's asked if she sees her latest move into prime time as a step into respectability.

"It seems to me that people on a prime-time show, particularly with a long run, are congratulated on it and asked the secret to their success," Lucci says. "But somebody on daytime is constantly asked -- I'm constantly asked -- 'How can you be on the show so long? Isn't it a wonderful steppingstone?' There seems to be a vicious cycle within the industry -- that the people on daytime want to be on prime-time series, and once anyone's on a prime-time series they seem to want to be on movies. So nobody's happy anywhere. I guess that's just human nature."

Tiny and feisty, resplendent in a royal blue suede dress held together with pearl snaps, Lucci looks the part not of the consummate vamp she plays on the air, but of a regular Ms. Fine Arts League. She also looks the part of the highest paid actress in daytime TV, which, at a reported salary well in excess of $500,000 a year, she is. Gold dangles from her ears. Gold bracelets and a pear-shaped diamond engagement ring decorate her hands. She has the poise of a statue.

And she is poised in another sense, because after the big ratings success of her prime-time NBC movie "Mafia Princess" last month, and with her "All My Children" contract up for renewal in March, Lucci must deal publicly and privately with the possibility of leaving the show.

There is still enough prejudice against daytime actors that most feel the need to attempt the leap to prime time and movies. And although few are successful, even daytime's biggest stars, like "General Hospital's" Genie Francis, have left the security of soaps in search of credibility. Lucci says that she "personally has run into less prejudice than anyone in the industry" but claims to feel a "great need" to do more films. Yet she is being very coy about whether she plans to stay or leave, telling reporters that she's "in the idst of that decision." She wouldn't even crack when Jane Pauley put the pressure on her on the "Today" show.

Certainly there can't be many other roles waiting around that are as yummy as that of Erica Kane Martin Brent Cudahy Chandler, the most vain, selfish, egocentric, flirtatious, ambitious, yet vulnerable of TV characters. Erica is a woman who sheds men as easily as she does her myriad fur coats. After emerging from a fire that claimed many lives with only an infinitesimal scratch on her face, Erica spent weeks wailing about her "disfigurement." She procured the first abortion on daytime TV while unblushingly telling her husband that she was as desperate as he to conceive a child. And she even has been known to berate her eternally understanding mother for the unthinkable shame of being married to a man with a hearing aid.

Although Lucci expects to be taken seriously as an actress for her work on "All My Children," she clearly sees the humor in Erica. Upon being reminded that Erica was last seen buried in an avalanche, she laughs and inquires, "Have I been found unconscious in the snow with my red gloves? It's wonderful," she says. "I have on high-heeled black leather Charles Jourdan boots and it's just a great picture in the snow, don't you think? Just great, clawing at the cabin door. You couldn't last 15 minutes in these little thin leather gloves and those high-heeled boots, but it just works."

Since Erica was a glamorous fashion model and is now a New York magazine editor, Lucci has the chance to indulge her passion for clothes. Each of the show's characters has a personal closet at the studio. Erica Kane has five. And her furs? "The furs come in daily; the furrier just picks out the cream and sends them over. I mean this is a cushy thing about being Erica Kane," Lucci chuckles. "It's wonderful. I could be playing the maid, you know, and I wouldn't get those furs!"

Lucci auditioned for the role in 1969 and the show went on the air in January 1970. Erica was then a high-school student, "the kind of girl who wouldn't go to study hall," Lucci says. "She'd get the pass and go to the girls' room and change her hairdo . . . My mother and I both laughed from day one. The audition scene was a scene between Mona and Erica -- Mona trying to get Erica to study her math and Erica just wanting to put on her mascara. 'Mom, leave me alone, what do I need with math.' She recognized it as a scene from life, and I did, too."

Lucci and her mother aren't the only ones who recognize these scenes from life. Suburban grandmothers, inner-city high-school students, professional athletes, secretaries and graduate school professors all crave their daily dose of daytime drama. On Lucci's 1983 visit to Washington, 5,000 people stood for hours in the steaming August heat, all for the privilege of watching their favorite soap stars wave as they emerged from a bus. Harvard University voted Lucci best actress of the year in 1980. And every month ABC sends her an enormous cardboard box stuffed with manila envelopes full of fan letters. She sits down for about three hours every week to autograph pictures.

Once in a while she just picks up the phone and calls a fan, she says. "There's one woman -- she was so mad at me, she had been writing she said for 10 years. She had written to Elizabeth Taylor and Sophia Loren and Henry Fonda and everybody you can name and they had all written her, and what was my problem?" Lucci looks a little guilty. "I'm not like that -- I don't mean to not answer somebody for 10 years, and I felt bad that she was so angry at me. And God knows if Liz Taylor could answer, I could answer.

"So I called this woman, and she said her husband was always making fun of her because I never answered, so her husband answered the phone and he -- I mean the pause when I said that it was Susan Lucci -- he couldn't believe it. He called, 'Dorothea, Dorothea!' Dorothea came to the phone and I spoke to her and we have been fast friends ever since."

Four days a week Lucci's workday begins at 7 a.m. when she says goodbye to her husband and two children and is driven from her Long Island home to the Upper West Side of Manhattan where "All My Children" is taped. On the way to the city she studies the 40 pages of script she is expected to perform that day. The morning is devoted to a run-through of the day's lines and the blocking of the show, when the actor's movements for the scenes are coordinated. The crowd of gawkers clustered at the entrances to the building makes it difficult for Lucci to venture outside for her 45-minute lunch break.

The episode is taped during the afternoon, and Lucci usually leaves the studio by 7, arriving home at 8. She says her schedule leaves little time for her to be involved with broader social concerns. "I think the women's movement has lost momentum because we all grew up and went out there and we're doing it all and now we're tired, we're very tired . . . It's enough raising your children, having a career and being a good wife. Let alone march."

She says she would love to do more movies -- "a couple a year" -- and she's "trying to figure out the best way to do that." Yet she insists that it is possible to do prime time and film, or daytime and film.

So it seems that she may well be happy to continue her role on "All My Children" if ABC will give her enough flexibility to take on movie roles. And since ABC's daytime shows are more than twice as profitable as its prime-time shows, accounting for more than two-thirds of the network's profits, it's likely that ABC will try to meet Lucci's demands -- particularly at a time when the ratings for ABC's prime-time schedule are trailing far behind those of NBC and CBS.

Lucci has garnered six Emmy nominations for her performance as Erica Kane, but has never won. "I guess the blue-ribbon panel doesn't care for my work," she gripes. "Every year I . . . get my hopes up all over. I feel like a little puppy dog. I get the nomination and I'm thrilled to be nominated, and then I don't get it. Then I'm disappointed again but I go back. I would love to win it."

Lucci has received far less publicity than Joan Collins, ABC's prime-time raven-haired vixen, despite the fact that Erica Kane was busy destroying lives long before Alexis Carrington sashayed her way into that Denver courtroom. Lucci herself was "in conversation" with the producers of "Dallas" to play the role of mysterious schemer Angelica Nero this season, but ABC wouldn't let her out of her contract to accommodate a CBS show.

Nevertheless, she says daytime soaps have an important advantage compared to the night-time variety: "You have all that time to play the gray areas," she says. "It doesn't have to be so black-and-white, hit-'em-over-the-head. And that time allows people in the audience to become emotionally involved and have an investment in those characters they choose to."

Enough of "All My Children's" estimated 11 million daily viewers have felt so strongly about the character of Erica Kane that they've made successes out of Lucci's initial forays into film. Producer Garry Marshall wrote a cameo for her in his 1982 feature "Young Doctors in Love." "When they showed it in the test markets -- I don't mean to toot my own horn, it was just so nice -- he called up my agent and said, 'When your client came on the screen, the movie theaters in Illinois, in Maine, in wherever they were showing, went crazy.' " Marshall responded by quickly adding as many soap star cameos as he could.

Lucci professes contentment with her life in the soaps. She doesn't have a nasty word for any of her costars on daytime or nighttime. Her producers are "lovely" and ABC is "lovely." In true Erica style, Lucci fell in love with her husband, a man 12 years her senior, at her own engagement party. They've been married 15 years.

So where, one may wonder, is the fire that fuels Erica Kane's repeated verbal assaults on the countless individuals who have interfered with her plans? Just ask Susan Lucci if anyone has ever tried to dismiss her lightly. Ask her about the caption under her high-school yearbook picture.

"The most jealous bitch in my high school class, who hated me from day one -- this girl, I think, got herself onto the yearbook staff simply so she could write my line," says Lucci, laughing. "It said, 'Short, but sweet.' " She bristles at the thought. "I have to tell you that I won almost every award known to man in my high school class. I played every lead in every play. I was an honors student, an exchange student, a cheerleader and I went out with the captain of the football team. There was no reason on this earth to put 'Short, but sweet' under my high school picture!"