ENTERTAINMENT : Scaring Up Some Fun : Thousands have crowded Universal Studios on nights when it transforms itself into a sprawling haunted house.

Halloween has traditionally been the domain of Knott’s Berry Farm, which has staged its “Knott’s Scary Farm” for more than two decades. But now, the Universal Studios tour is calling on its goon squad--Frankenstein, Dracula, the Phantom of the Opera--to muscle in on the action.

With “Halloween Horror Nights,” Universal has transformed itself into a sprawling haunted house for six nights ending Saturday. So far, the special evening sessions--they require a ticket separate from daytime attractions--have drawn sellout crowds of 16,000 or more.

“This is a natural for us,” said Terry Winnick, the theme park’s general manager. “Universal’s history with monsters goes back to 1925 and ‘The Phantom of the Opera’ with Lon Chaney. They were all shot right here on this lot. This is hallowed ground.”

Not that Knott’s is shaking in its boots. The Orange County theme park also reports sellout attendance. Its special sessions run for 11 nights ending Sunday and include rides, shows and 800 performers, including Elvira.

“The thing that makes us different is our location,” Knott’s spokesman Stuart Zanville said. “When you start with a ghost town and you have people walking through those fog-shrouded streets with monsters jumping out at them, it’s a little different than a tram ride.”

Universal, for its part, has spent several million dollars on “Horror Nights.” At 6 each evening, when the park closes, workers scurry to transform the grounds for the 7 p.m. reopening. Three hundred performers have been hired to play the roles of various ghouls and monsters. The park has also called on its special-effects technicians.

“We have the use of all of our motion-picture techniques,” Winnick said. “All the fires and smoke and explosions and re-creations of great scenes from the movies--that kind of stuff is different from just putting up cobwebs and having monsters jump out of the fog.”

As a result, the rides and shows scattered across the 425-acre grounds range from horrifying to humorous:

* For “Nightmare Alley,” Universal’s best blood-and-guts people have put together a maze that resembles a film vault overrun by ghouls. There are plenty of scares as guests wander along pitch-black corridors. The walls thump and rattle. Monsters jump out from around corners. And there are several rooms of inspired special-effects work.

* For Penn & Teller fans, Universal has a special treat. The performance art magicians put on a 45-minute show. They perform several old favorites: the “Casey at the Bat” escape act, the needle and thread swallowing trick and some salacious fire-eating. A new bit is debuted as well, combining traditional sleight of hand with striptease and the prom scene from “Carrie.” The duo mesmerizes as always.

* “Ghoulia Wild’s Roadside Cuisine” is a smaller show that’s not to be missed. Blood spatters the kitchen set. Squashed cats, armadillos and possums hang over the stove. And there’s the host: “that whiz in the kitchen and menace on the road” who specializes in preparing the varmints she runs over. When she pulls a hitchhiker out of the fridge, the livers and intestines fly. (A suggestion: Don’t sit in the front row.)

Visitors to “Horror Nights” can also find such old favorites as the “E. T. Adventure” and “Backdraft” in operation. The tram runs, too, but with a different course that includes a particularly realistic “tram wreck” site.

Like Knott’s, Universal suggests that its Halloween attraction isn’t suitable for children under 7. In a publicity twist, the movie theme park has also provided a team of psychologists to counsel guests who are either terrified by the attractions or, perhaps, distraught from standing in lines.

Where and When

What: ‘Halloween Horror Nights.’

Location: Universal Studios, 100 Universal City Plaza, Universal City.

Hours: 7 p.m. to 1 a.m. tonight and Saturday.

Price: $27.

Call: (818) 622-3801.