LOS ANGELES — With the box office success of “Smile,” “The Black Phone” and his “Barbarian” this year, writer-director Zach Cregger says it’s clear that “original horror is working right now.”

Though the genre has long relied on franchises like “Halloween,” “Saw” and “The Conjuring,” Cregger says younger filmmakers are finding scary features “creatively fertile territory” for exploring unexpectedly complex themes.

Cregger’s solo directorial debut was lauded as a late-summer sleeper hit, making more than $42 million worldwide on a modest production budget of $4.5 million.

Now available on streaming, it tells the story of a young woman (Georgina Campbell) who finds her Airbnb-rented house in a half-ruined section of Detroit weirdly occupied by a stranger (Bill Skarsgård). It goes on to subvert a number of horror conventions, and found audiences outside the traditional genre fans.

“Adults that are craving new and groundbreaking stuff, there’s not a lot of places to go,” Cregger said. “Studios are only putting money into big IP superhero stuff, which for me as a 40-year-old man, I’m not really like drawn to that.”

He struggled to find a studio to back his film. Cregger said he looked up the production companies associated with every horror movie that has been made in the past 15 years, then sent his script to all of them. None agreed to fund the project.

As he was considering selling his house and going into debt to pay for the film himself, Cregger found BoulderLight Pictures, a small production company based in Los Angeles. “They were the first people that read it that were not daunted by the shift in tone,” he said.

Another horror directorial debut, “Smile,” topped the box office for two weeks after its release in September and has made more than $169 million worldwide. It examines the ripple effects of trauma.

Cregger is optimistic about audiences’ growing appetite for horror films that aspire to deliver more than jump scares and gore, a trend he thinks is indebted to films like Jordan Peele’s “Get Out” and Ari Aster’s “Hereditary.”

“You feed somebody Doritos, but then you slip some broccoli in there,” Cregger said. “‘Barbarian’ does not have a social agenda. It really doesn’t. But there is stuff in there that I think can start conversations.”

“Barbarian” star Justin Long praised horror’s often surprising ability to probe deeper questions, citing “Saint Maud” and its exploration of mental illness. And even as an actor, he said the director’s themes were woven cleanly into the story.

“There were moments where I felt like, ‘Oh, yeah, wait a minute, I think I just ate some broccoli,'” Long said.