Riverdale” showrunner Roberto Aguirre-Sacasa is expanding his hold on the high school drama genre, and the small screen adaptation of classic Archie Comics characters, with “Chilling Adventures of Sabrina” for Netflix. “I’ve always loved coming-of-age stories, they’re some of my favorite stories,” he says. In splitting his time between both shows, he is launching the first season of “Sabrina” while constantly looking to find new ways to make the third season of “Riverdale” feel “as fresh and exciting” as a first season show.

What was the entry point for you with adapting “Sabrina”?

The entry point for me was the coming-of-age story. And I love horror — I love the genre. And I love the Archie Comic characters. So this felt like it was a confluence of a bunch of stuff. A lot of horror is set during or tied to coming-of-age — “Carrie” is the best example: Her telekinesis manifests when she hits puberty. The girl in “The Exorcist” is possessed when she’s around 13 — it’s kind of an important point, more in the novel than in the movie. I’ve always been attracted to that, and I’d been wanting to do a horror project for years in television.

The titular character in “Sabrina” comes from a family of witches, but other than that genre element, what is the biggest difference between that show and “Riverdale”?

In some ways, “Sabrina” the show is more innocent than “Riverdale.” And the center of the show is more on the Spellman family and less on the high school kids. I think that took a little bit of getting used to. “Riverdale” is also a real ensemble and in “Sabrina,” you’re really following one girl’s journey. That is a slightly different realignment that had to happen. [And] “Riverdale” is pretty gonzo storytelling — it moves, it’s like an out of control train. “Sabrina’s” a little bit slower paced and a little more methodical and thoughtful.

What makes “Sabrina” a more innocent show, even with the dark supernatural elements?

In terms of the sexuality and stuff, the “Riverdale” kids are always having sex, everywhere. When I say it’s more innocent on “Sabrina,” [she’s] really a 16-year-old girl who has not had sex and Harvey is a boy, 16, who hasn’t had sex. I think that is a core innocence that is difference from “Riverdale” where the kids are acting a lot more like grownups. The other big difference is Kiernan is an 18-year-old playing a 16-year-old [which] is a big difference than a 27-year-old playing a 16-year-old or a 28-year-old playing a 16-year-old. She feels younger. And you kind of feel protective of the actors and you don’t want to put them through horrible things!

In speaking to the genre elements, what line do you want to walk with how dark to get?

It’s something that we talk about every episode. As the season goes on the horror gets deeper and deeper, but I’ve never been into exploitative horror or torture horror, so it’s always been more psychological and classical. The movies that we reference all of the time are “Rosemary’s Baby” and “The Exorcist,” which are very scary and do have gore but are not slasher or things like that.

How does the genre lend itself to topical issues you want the show to address?

For sure when you’re dealing with witchcraft you’re dealing with themes of female sexuality and female empowerment — to be a witch is to have powers and be empowered. In our universe, witches worship the Dark Lord, who is a patriarchal figure. So the show is kind of based on a paradox: These women are empowered [because] they’re witches, but they are subservient to a patriarch. And when we meet Sabrina, she’s about to have her dark baptism, and she’s saying, “Wait a minute, something about this feels wrong. I like that I’m a witch, and I live that I’m getting more powers, but I don’t like that I’m turning my freedom over to this guy.” And that’s the paradox in our world, and that’s how we play witchcraft. And our forces of evil are patriarchal figures — the Dark Lord, the High Priest, Principal Hawthorne. They’re all variations on that theme. And our lead character, Sabrina, is questioning all of that and pushing against all of that.

Her aunts are witches of a different generation. How are their perspectives and experiences in contrast to Sabrina’s?

The “Sabrina” characters, like the Archie characters but a little less so, are archetypes. Zelda is a very devout believer in the Church of Night; Sabrina is rebellious and questioning and challenging the Church of Night; Hilda is somewhere in the middle — back when she was a girl there weren’t as many options or the opportunity to question.

What is most important about getting into the minds of such female characters?

The writers’ room is predominantly female and a wide age range. We all work on the show and the episodes together, and we all look at these themes from different points of view.

“Sabrina” was originally being developed for broadcast television. What, if anything, are you doing differently since the show landed at Netflix?

One of the great things about being on Netflix is you can push the envelope a little bit more. … The biggest difference is that on a network show you have to turn in a cut that’s 41 minutes and 30 seconds, and on Netflix, whatever the cut is, that’s what it is. And sometimes even having three extra minutes allow you to get a little bit deeper.

What is the biggest challenge of writing the third season of “Riverdale”?

Besides getting the cuts down to time, the other big challenge of “Riverdale” is we have such a huge cast of characters, and they’re all played by wonderful actors — the kids are all stars, the grown-ups are all stars, any of them could carry their own show. And the challenge is getting the right balance. … We’ve had a lot of really open discussions about how we don’t want this to feel like a third season of a show, we want this to feel as exciting and fresh as a first season show, and it means working a little harder to do that. But the flip side of that is [as] a third season show we can take a little more risks, there’s a little more trust from the network and the studio, and you can build on a history now. There’s a history that these characters have that we’ve actually seen on screen, and we can harness that. So it’s taking those good parts and really pushing to keep the stories fresh and exciting.

With so many characters to service, and so many of their stories diverging greatly to focus on individual concerns, how concerned are you about bringing the core group back together for tentpole moments?

It’s something we struggle with in the room. Every so often we do consciously say, “Let’s try to slow this down a little bit” or “Let’s just tell a simpler story,” and because of expectations and because the adventures these characters have done on, it’s hard to go back and tell a simple story. We used to tell stories where Archie has stage fright at the variety show, and now Archie’s in jail! The stakes are a little higher. The show has become what it was destined to be, I think, and it found itself, so it’s hard to go back on that. … When we were talking about Season 3 we realized, “Wow, Betty and Jughead were apart for most of Season 2.” She was focused on the Black Hood, he was focused on the Serpents — she was focused on Chick, he was focused on taking down Hiram Lodge. Their journeys were pretty separate, and this season we are trying to focus on aligning them more. So we do make conscious decisions about who we want to pair up and stuff, but sometimes the story guides us.

Do you feel pressure or obligation to keep putting the couples back together, even after they hit rough patches, because they are such iconic comic couples?

I am an optimist, and this is not reality, it is “Riverdale,” so I love when high school kids say they’re end-game because they are still so young. There’s always a healthy push and pull. Me personally, as a fan and as a human, I am rooting for them — but there’s definitely more drama when they break up and are dating other people and stuff, and that’s part of high school, too.

In the third season premiere, “Riverdale” teased the possibility of dark magic. Are you intentionally setting up a crossover, or was Betty’s point of view of the ritual not to be trusted?

That’s a big mystery — what happened exactly at the end of the episode when Betty has her seizure. The central mystery in “Riverdale” is a pretty gruesome double murder or suicide in the woods that has a lot of ritualistic elements surrounding it, and we’re sort of using as our inspiration the first season of “True Detective,” which felt like it was telling an occult murder mystery story. And that’s where we’re at. Whether it goes to the supernatural place or not, probably not. But if we could figure it out to everyone’s satisfaction, I’d love to do a crossover.