Fall is arriving at the movie theaters, and for some moviegoers, it’s time to scream.

Horror movies are making a big splash at theaters, most of them before Halloween — with classic titles getting revisited, new ideas being tried and familiar tropes trotted out in new forms.

Horror, said Mike Hardle, founder of Salt Lake City’s Halloween-weekend convention Fear Con, “is a very pure form of entertainment. It kind of appeals to your basic, primal instincts, like survival.”

Cassidy Ward, an editor at the Salt Lake City-based nerd-news website Big Shiny Robot, said being scared is in our DNA.

“We have tens of thousands of years of evolution hanging in the backs of our heads,” Ward said. “Most of that time, there was something to be afraid of. There were monsters in the dark. … Since we’re not getting that in our lives anymore, we have to seek it out in other ways.”

The fall movie season kicks off this weekend with a title from the modern canon of horror: Stephen King’s “It,” in which seven 13-year-olds face a recurring terror that has gripped their town for generations.

The emergence of “It” — based on King’s 1986 novel, which spawned a 1990 TV miniseries — is part of “a throwback to the ’80s,” Hardle said.

(Brooke Palmer | Warner Bros. Pictures) Pennywise (Bill Skarsgard), a clown that terrorizes children in a Maine town, is the central figure of "It," based on the Stephen King book.

Another example of a rebooted horror franchise is “Flatliners” (opening Sept. 29), a remake of the 1990 thriller about medical students who stop their hearts for kicks — and discover something sinister crossing back from the other side. The original starred Kiefer Sutherland and Julia Roberts; the new version features Ellen Page, Diego Luna and Nina Dobrev.

“It’s time to reboot some of the classic ’80s stuff, for a generation that hasn’t seen that yet,” Hardle said.

Another ’80s trend — serial-killer movies — may be coming back, too.

Swedish director Thomas Alfredson (“Tinker, Tailor, Soldier, Spy”) adapts Jo Nesbø’s disturbing serial-killer thriller “The Snowman” (Oct. 20), with Michael Fassbender as detective Henry Hole. Meanwhile, “Jigsaw” (Oct. 27) resurrects the puzzle-creating killer from the “Saw” movies, a franchise that supposedly concluded back in 2010. And a chainsaw-wielding killer is the baddie in the horror-spoof “Boo 2! A Madea Halloween” (Oct. 20), with Tyler Perry reprising his housecoat-wearing grandma character.

(Brook Palmer | Lionsgate) Laura Vandervoort stars as Anna, one of the victims of the resurrected Jigsaw Killer, in the horror movie "Jigsaw," a continuation of the "Saw" franchise.

New technology inspires new horror, Hardle said. The internet and social media have spawned a new subset of horror movies — such as “Friend Request” (Sept. 22), where the scares are sparked when a college student (Alycia Debnam-Carey, from “Fear the Walking Dead”) unfriends a classmate online. An old-school technology pops up in “Polaroid” (Dec. 1), in which an instant camera brings instant pain to anyone whose picture it takes.

“Happy Death Day” (Oct. 13) recycles an old idea into something scary, as a college student (Jessica Rothe) is murdered on her birthday — and must relive that day, over and over, like “Groundhog Day.”

Even auteur directors are getting their scare on. Darren Aronofsky (“Black Swan,” “Noah”) has Jennifer Lawrence going mad in an old house in “mother!” (Sept. 15). And sisters Kate and Laura Mulleavy, known for their Rodarte fashion brand, make their movie debut with “Woodshock” (opening sometime in October), with a woman (Kirsten Dunst) descending into paranoia.

Trends in horror “absolutely reflect what’s going on in the wider world,” Ward said. In the ’50s and ’60s, as Cold War headlines raised fears of nuclear annihilation, radiation-driven monsters like Godzilla were in vogue.

More recently, Ward said, “the big thing for a while has been zombies. … We’re the most comfortable, we’re the safest we’ve been in the history of humanity. We’re king of waiting for things to come crashing down.”

Horror movies, Ward said, appeal to people for the same reason rollercoasters do. “You’re putting yourself in a dangerous situation,” he said, “but in a controlled environment.”