When it comes to developing three-dimensional, well-rounded characters, television is still the best place for performers to work. This is especially true when the role itself is mysterious and keeps the audience guessing. Such complications not only attract high-caliber talent to the roles, but they are also what in turn allows that talent to be celebrated come Emmy time.

For Jessica Biel, whose work as “The Sinner’s” Cora — a woman who snapped and killed an apparent stranger — earned her a nomination for lead limited series/movie actress, part of the appeal was that the character was an unreliable narrator.

“It was trying to understand how you would make that work on television on the screen,” she says. “Could I do it? This is so challenging and hard. Is any audience member going to want to follow this person? All of those ideas were really what drew me to her and this piece.”

The narrative structure of “The Sinner” unraveled the truth of Cora’s past and revealed traumas and memories, some of which she had repressed and some which she was just hiding.

“To me, it was like a survival story; she was trying to maintain normalcy,” Biel says. As an actress she “made the same choices I would have made if I was playing someone who wholeheartedly believed in their past or their journey.”

However, portraying an unreliable narrator can be extra complicated when the character is based on a real person. Laura Dern, a seven-time Emmy nominee who took home the gold last year for her supporting role in “Big Little Lies,” was recognized for portraying a version of writer-director Jennifer Fox in HBO’s original movie “The Tale.” The story was based on Fox coming to terms with sexual abuse in her own childhood.

“As much as you can write it, you can’t always guide how an actor is going to feel [the moment] or express it,” Dern says. “[Fox] did have to surrender and at times get out of our way … that was the trickiest thing, because you obviously want to be respectful. But, in a way, you become territorial as the actor in it. It’s a weird dance.”

What was key for Dern was that Fox “allowed me to be a real collaborator.”

“We examined and reconsidered how the story would be felt from the beginning to the end,” she says. “This was not an easy task; it was a lot.”

Similarly, Regina King — nominated for lead limited series/movie actress after three consecutive nominations (and two wins) in the supporting category for “American Crime” — met with a mother who lost their child to police violence to get insight into the grieving headspace of her “Seven Seconds” character Latrice.

“It was important [we were] honoring the pain these parents lived with every day [and] that we weren’t exploiting it,” King says. “That was a conversation we would have often as the episodes would come up. I wanted to make sure we were always careful of that. That was a big responsibility once we decided to take this ride together.”

Even some nominees in the comedy category have had darker, more emotionally complex turns this season. “Black-ish” took a big swing in season four, as Bow (Tracee Ellis Ross) struggled with postpartum depression and a (temporary) separation from her husband, Dre (Anthony Anderson).

“I was very excited about [the postpartum arc], mostly because I hadn’t seen that really done,” she says. “Tackling any kind of medical disorder or sickness in the black community is an important thing to keep shining lights on.”

With the separation, “it was a little different because the conflict we were exploring was within the relationship versus something outside the relationship, so it was a challenge,” she continues. “But it was a good challenge. … I love that we’re not just doing funny things — we’re saying something. We’re unpacking things that don’t always get to get unpacked.”

Interestingly, the episode Ross submitted for the Emmy this year is “Elder. Scam,” in which Bow is involved in a lighter — but still colorful — storyline about struggling to accept her college-age daughter as an adult.

“I don’t find one harder than the other; they require a different part of me,” Ross says of the juxtaposition of the lighter comedy with the heavier, more emotional material. “You can play and be silly and then snap right into comedy. You can’t quite do the same thing with dramatic stuff. … [But] I find both come from the same place. They come from a place of honesty for me.”

The same bodes true for “Mom” star Allison Janney — a 14-time nominee/seven-time winner — who is still finding challenges in portraying a recovering addict, five seasons in.

“Bonnie has one of the most bipolar egos in a character I’ve ever played,” she says. “She goes from being absolutely selfless and empathetic, to being absolutely self-serving. You never know which tool she’s going to take out of her bag.”

In many ways, though, Janney doesn’t see the complexities of her character as complications at all, but rather fascinating nuances.

“There is always more to tell about these women. The things [the writers] can come up with because our pasts are so checkered, there is literally nothing they can throw our way that’s not believable,” she says. “We can take bigger chances because it is in the comedy format, but we see women really making progress in their personal growth, and that’s what roots the show.”

For some, such as limited series/movie nominee Michelle Dockery, who previously was nominated three times as a lead actress for “Downton Abbey,” the most complicated part of a character can come from something external, though. To portray horse rancher Alice in Netflix Western “Godless,” Dockery had quite a few physical challenges with which to contend.

“These are massive animals,” she says of working with the horses. “It’s one thing knowing the character and knowing your lines, but [doing it while] maneuvering these huge animals can be quite a challenge. Especially if you’re trying to look cool up there, like you’ve been doing it your whole life.”

But she “was immediately drawn to Alice,” she says. “It was a character that was very different than anything I had played before.”

Like Dern, Dockery says working through the toughest parts with writer-director Scott Frank was vital. “Scott encouraged me to be brave enough to think what you’re feeling, as opposed to showing it,” Dockery says.

And it can be even more difficult when you’re not only playing a complicated character, but also are the person everyone is looking to for guidance with their own complex performances.

“[It was tough] to be the director, help the kids, step into my performance and let go of all the things when I’m working,’” says Pamela Adlon, a seven-time nominee seeing her second consecutive nom for playing single-mom Sam in “Better Things.”

Adlon wrote and directed a number of episodes of the second season of the FX comedy, including the sixth episode “Eulogy,” for which she is in contention this year. In that episode, she had to help the young cast get to a certain place emotionally while still being able “be in the moment as an actor [and] to let go and trust my actors so they could trust me, and our performances [could] bounce off each other and get to an elevated place.

“That would have probably been the biggest challenge, acting-wise,” she says.