Cheryl Gerber for The New York Times

Bryan Batt, left, and his partner, Tom Cianfichi

LOS ANGELES
THERE’S a bisexual woman in “Bones” and a lesbian couple on “The Goode Family.”

“Dirty Sexy Money” features a transsexual and “Brothers & Sisters” a gay marriage.

In “Mad Men,” the Emmy-winning drama set in the early ‘60s, there’s Salvatore Romano, a self-loathing homosexual who marries a woman but pines for a male co-worker.

Never before have gay story lines been so prominent. Nor have there ever been so many gay, lesbian, bisexual and transgender characters on television — 83 by a recent count from the Gay and Lesbian Alliance Against Defamation, not counting reality shows, daytime dramas or gay-oriented cable networks.

Hollywood, with its depictions of cowboy lovers and lesbian neighbors, has done much to make gay men and women part of mainstream American life.

At the same time, gay actors like Neil Patrick Harris and T. R. Knight play heterosexual characters on TV and in film, while couples — Ellen DeGeneres and Portia de Rossi — are covered by celebrity magazines as if they were any old romance.

“We’ve gone from the revolution to the evolution,” said Howard Bragman, a longtime Hollywood publicist who is gay and has advised actors like Amanda Bearse, of “Married ... With Children” and Dick Sargent of “Bewitched” on how to handle their coming out.

Yet for most gay actors, Hollywood is not a warm and fuzzy episode of “Will & Grace.” Today, it is certainly more acceptable to be openly gay. But these actors must still answer wrenching questions: Just how candid do you want to be? Would you be happy appearing only in comedies, or being pigeonholed as a character actor? And what does the line “You’re just not right for the role” really mean?

Jasika Nicole, 28, an F.B.I. agent on “Fringe,” a new Fox drama, said that as bigger parts became available, her manager, John Essay, sat her down and asked how public she wanted to be about being a lesbian. Some roles could be lost, he told her, as would some fans.

Mr. Essay, who is gay, said he encouraged openness but warned clients of the risks.

“If it becomes exaggerated,” he said, “you just become the gay actress instead of a wonderful actress.”

Perhaps, he suggested, she didn’t want to be too vocal about it.

Ms. Nicole, who has a girlfriend, said she would just be herself. She has been open about her sexual orientation since she started dating women about 3 ½ years ago, while she was filming “Take the Lead” with Antonio Banderas in Toronto.

Now, as she becomes better known, “There’s no way I can keep quiet,” she said. “I want to be clear this is my partner. I don’t want to make that shameful in any kind of way.”

But most other actors calibrate just how out they want to be. Openly gay can still mean they would rather not talk about it. Most gay actors are mum in public or on the set, even if they don’t hide their orientation in private, actors and others in the entertainment industry said. Although most may no longer participate in charades — the “girlfriend” on the red carpet, for instance — many adopt a don’t ask, don’t tell policy.

Why? For both men and women, being openly gay, at least for now, means giving up any hope of superstardom.

“The industry is persuaded that being known as gay will undermine your credibility both as romantic lead or an action star,” said Larry Gross, director of the Annenberg School for Communication at the University of Southern California and author of a book on media portrayals of gays and lesbians.

“They don’t test it,” he said. “We’re waiting for the Jackie Robinson moment when someone tests that assumption and discovers it’s not true.”

GAY actors don’t just lose the potential of becoming the next Brad Pitt or Reese Witherspoon, they lose the opportunities for fame that ensure plum jobs, said Jason Stuart, an actor and comedian who chairs the lesbian, gay, bisexual and transgender committee of the Screen Actors Guild. It is no coincidence, he said, that even the title role in “Milk,” based on the slain gay hero, Harvey Milk, went to Sean Penn, an Oscar-winning actor who is straight.

“There are not enough famous gay actors to play these roles,” he said.

Dan Jinks, a producer of “Milk,” agreed. The film’s director, writer and two producers are openly gay and so are a number of actors who play gay and straight roles, including the Tony Award-winners Denis O’Hare and Stephen Spinella.

But for the lead, Mr. Jinks said, “Our first concern was to get the best actor that we could get who was enough of a movie star to get the movie made.”

“When one is casting a film for a lead role we always have to ask that awful question: ‘Who puts bodies in seats?’ ” Mr. Jinks said. “Who has carried movies previously? Sadly, there don’t seem to be openly gay actors that could carry a movie, but I think that will change.’ ”

When they don’t land a part, some gay actors say they never know how much of a factor their homosexuality plays.

“There are definitely people who make the decisions who don’t care and there are people who do care,” said Abraham Higginbotham, creator of the Fox sitcom “Do Not Disturb.”

The actor up for the part, he said, “would hear, ‘You’re not right for the role.’ ”

But some casting directors said it was now much easier to cast gays. Mary Jo Slater, a film and television casting director, said barriers were falling because of the success of shows with openly gay actors in them.

Ms. Slater cast a transgender actress, Candis Cayne, in “Dirty Sexy Money,” and noted: “She’s, like, a big star now.”

“I look at their ability to perform the part,” she said. “I don’t really think it matters.”

But what about straight parts? Chad Allen, 34, a child actor on shows like “St. Elsewhere” and “Dr. Quinn, Medicine Woman,” said steady work dried up in 1996 after a tabloid ran a photograph showing him kissing another man. The “Dr. Quinn” cast was supportive and he remained in the family-oriented show, he said, but after the series ended, “It was tough.”

“I couldn’t get an audition for a pilot after that,” he said.

But Mr. Allen, who attended college and continued to do some work in film, found new roles a few years ago, with the advent of gay-oriented cable networks. In channels like Here! and Viacom’s Logo, openly gay actors have played lead roles as private detectives, vampires and superheroes. Mr. Allen stars in a mystery series on Here!, in a role he describes as “a good detective who happens to be gay.”

And in a sign of the times, the show gave him opportunities for gay and heterosexual guest roles in television shows like “C.S.I.: Miami” and “Cold Case.”

In 2006, Mr. Allen incurred the wrath of some conservative ministers after he was cast as the lead in “End of the Spear,” produced by an evangelical film company, about five American missionaries killed in 1956 by an indigenous tribe in Ecuador.

The church pastors objected to his sexual orientation and his political advocacy for gay causes, but Mr. Allen said the fear of casting someone like him is less and less an issue.

“We’ve been witnessing a slow erosion of this fear as audiences show up,” he said.

One test of how far things have progressed, some industry analysts said, will be the kind of roles Mr. Harris and Mr. Knight are offered once they end their current hit shows. Although they are openly gay, they landed the parts before they came out. And tellingly, they made statements about their sexuality only after being outed by bloggers in the case of Mr. Harris, and by a homophobic incident with a co-star in the case of Mr. Knight. For now, more gay characters and better scripts are adding up to more fulfilling work. It wasn’t too long ago that actors like Bryan Batt of “Mad Men” could find good parts only on the stage. Even in theater, he said, his agent was once told by a casting director, “I just can’t see Bryan as a baseball player.”

“I didn’t know what to make of that,” said Mr. Batt, 45, who came out publicly in the mid-90s when he landed the part of Darius in “Jeffrey,” the off-Broadway play about sex and romance in the age of AIDS.

As an actor, Mr. Batt said, he doesn’t want to be pigeonholed into playing only gay roles, but it’s hard not to feel “proud and happy” with Salvatore. He begged Matthew Weiner, the show’s creator, to let the character get married. “It’s a realm of reality that television had not really explored,” he said.

The character is addled by the kind of inner conflict — not able to be himself, forced to act like the sexist guys in the office — that “continues to happen,” and not just in 1960s period dramas, Mr. Batt noted.

That such a meaty part went to an openly gay actor “speaks volumes about how far we’ve come,” he said.