Don’t go by this writer—who was spooked by Abbott and Costello Meet Frankenstein—but even the Saw/Hostel faithful could befoul their Underoos at Fright Dome at Circus Circus.

“We always have someone on mop duty,” says Fright Dome creator Jason Egan. Six haunted houses, four “scare zones” and 25 rides/attractions await those with the inner guts to face those live—sorry, “undead”—zombies wearing guts on the outside.

Even when deactivated during a recent walk-through—minus the actor/monsters you’ll encounter—the claustrophobic, dizzying labyrinth of “The Slaughterhouse” with its bloody butcher figures, sinister-looking kitchens (torture chambers?) and fake disemboweled pigs suddenly hanging in front of your nose is nerve-rattling.

“People are so desensitized by horror movies now because they really go to extremes,” Egan says. “We have to keep up. I can’t just put someone in a sheet or a cloak anymore.”

Credit the creepy props, masks and sets to a team led by Egan and his fright-freak partner, Hollywood FX specialist Gary J. Tunnicliffe, whose resume reads like a horror hit list—Hellraiser, Halloween, Candyman, The Exorcist, Blade and Scream among them.

“I’ve seen 6-foot-10 grown men, 300 pounds, getting the heck scared out of them,” says the genial, mild-mannered Egan (note his “heck” usage). “We warn people it will be scary. But we also have safe zones—non-scare zones—and our actors are trained on where the limits are. You’re not going to have your chainsaw out when a tiny 9-year-old is crying; you’re going to back off. They use their judgment wisely.”

There’s even a name for that: “Scare quality control.” And there’s much to control at this Halloween season horror haven, now in its 13th year, that last year ranked No. 2 on The Travel Channel’s list of haunted attractions. Around 400 actors, made up and dressed as the most frightful characters on this plane of existence—plus the Great Beyond—prowl the grounds of what, for the other 11 months, is the Circus Circus Adventuredome.

Consider the breadth of attractions designed to suck the breath right out of you. New this year is the interactive “Insanitarium,” where the heartiest of souls must check in at a nurse’s station to sign voluntary commitment papers. Inside, you’ll have to escape a deranged surgeon-turned-murderer while coping with the freezing temperatures of body lockers, the heat of a crematorium and rotting morgue corpses. (The props were gleaned from the Norwich State Hospital, a notorious insane asylum, shuttered in 1996, and infamous for reported paranormal encounters.)

Also this year is the premiere of Friday the 13th: 4-D as bloody icon Jason Vorhees slashes 13 victims in 13 minutes (not only a horror buffet, but a lesson in efficiency) at the Special FX Theatre, with its built-in seat vibrations and water sprays. Plus, a “Freakshow” area will host scary, live sideshow acts, carnival games and thrill rides, including two roller coasters.

In case you’re wondering: “I put limits on myself all the time,” Egan says. “There’s another haunted attraction in town that likes to touch and grab you and some of them—they call them extreme haunted houses—they use sexual words. That’s just stupid. We are as gory as it gets, but I don’t need to cross that line.”

Growing up in Omaha, Neb., Egan got hooked on Halloween early, and had a pipeline into the business via his uncle, a producer who has worked with Jerry Seinfeld and would bring Egan on rock-group tours.

Today, the 37-year-old entrepreneur owns Las Vegas-based Egan Productions, dealing in artist management, production, set-building, prop design, marketing, public relations, graphics and social media. Still, Egan lights up like a big kid over Fright Dome—particularly when recalling how celebrities fare within its walls.

Ozzy and Sharon Osbourne? “Ozzy was deathly afraid of clowns. Didn’t want anything to do with the clown house. But the nicest people—took me out to dinner afterward.” Michael Jackson? “Scared of everything. When his kids were on the roller coaster, we were talking and he was like, ‘We have to bring this out to Neverland and all the actors and have a big scare park.’” Actor Kevin Hart?: “He was a blast. And scared out of his freakin’ mind.” Stevie Wonder? “He was touching all the actors’ faces. They were wearing prosthetics and he was having a ball with it. It was probably sensory overload for him.”

And me. And you. And … everyone.

Circus Circus 7 p.m.-midnight through Oct. 18, 22-25 & 28-31, starting at $35.95, with fast pass $55.95, with VIP guided tour $89.95 plus tax and fee. 702.794.3939