When we watch movies, we generally assume that the actors are acting. That is basically their entire job description, after all. Even when their performances are so impressive that they receive Academy Awards, we know that it’s all just make-believe… right? Well, it turns out that actors were actually straight up terrified while filming scenes plenty of times!
Poltergeist
There were a lot of weird things going on during the filming of horror movie Poltergeist. The production used real skeletons, and the actors claimed that there was some weird and creepy energy on set the whole time.

But the scariest thing for actress Jobeth Williams was when she had to swim in a muddy pool with electrical wires and lights nearby. She was terrified that she would be electrocuted. Director Steven Spielberg reassured her by putting on boots and standing in the pool with her. “If it gets you, it gets me too,” he said.
The Shining
The stories about the set of The Shining are notorious in Hollywood. Directed by Stanley Kubrick, The Shining is thought by many to be among the greatest horror films ever made. This is in part because of the actors’ incredible performances.

The truth is, however, that much of actress Shelley Duvall’s terror and anxiety was completely real. Kubrick was known to be a perfectionist, and he would make Duvall do some of the most intense and scary takes over 100 times. The amount of stress that Duvall was under caused her to experience panic attacks and left her in tears. Her hoarse voice and red eyes weren’t acting – she was actually on the verge of breaking down!
It
Actor Bill Skarsgard’s portrayal of the evil clown Pennywise in the 2017 horror movie It certainly was creepy. Pennywise terrorizes children in a small town, and Skarsgard took his role seriously. He said that when he was in the makeup, he didn’t act silly – instead he stayed in character, always acting weird and creepy.

During one scene, a bunch of kids come face to face with the terrifying clown. The children acting in the scene hadn’t seen Skarsgard in costume yet, so when he came out in full Pennywise character, they were actually really scared. One kid even started crying. That’s when the director called, “Action!” The kids’ fear in that scene is definitely real.
The Abyss
In science fiction movie The Abyss, the characters dive deep into breathable liquid without equipment. These scenes were really shot underwater, but of course in real life, the actors could not breathe the water.

In order to keep the scene believable, actor Ed Harris would hold his breath as he dove underwater without oxygen. When he needed air, he would signal to the crew, and a diver would come down with an oxygen tank so Harris could take a few breaths. One time, however, the diver got stuck. Another diver came down to Harris but the regulator was upside-down, and Harris ended up with a mouth full of water. The cameras kept right on rolling, capturing the whole event.
The Blair Witch Project
In The Blair Witch Project, three film students hike into the woods to make a documentary about the legendary Blair Witch. The students disappear, but a year later, their cameras are discovered, and their scary footage is the movie that the audience watches.

As it turns out, the three actors playing the students actually were lost in the woods for some of the scenes. The directors sent the three actors out on their own with cameras, gear, and a rendezvous point, and told them to keep on filming. But the actors actually did get lost! A few scenes in the film were their real struggles to figure out where they were supposed to go.
Alien
One of the scariest scenes in horror film Alien is when the alien comes out of the astronaut’s chest. The characters all look really frightened, and it’s because they actually were!

The actors thought that the blood and guts would be added as special effects, but that was not the case. The director didn’t tell the actors that there would be real innards flying at their faces. So when they shot the scene, the actors really were scared and horrified when they were sprayed with pig insides.
Willy Wonka and the Chocolate Factory
Willy Wonka and the Chocolate Factory isn’t a horror movie, but there sure are some freaky parts. The director didn’t tell the child actors the details about each scene until they were right there in the middle of it.

During the scene where Willy Wonka takes the kids on a scary boat ride, the actors had no idea what was happening. Some of them even thought that Gene Wilder, who played the candyman, had gone bonkers. When they look scared in the boat, it’s because they actually were.
The Birds
It seems pretty cruel to expose your star actress to one of the things that scares her most, but that’s just what Alfred Hitchcock did when he made horror film The Birds.

Tippi Hedren, who played the main character, really didn’t like birds. So Hitchcock told her that they would use mechanical birds during filming. That turned out to be a lie. In a lot of scenes, real live birds were flying at her face, as she unhappily tried to escape and swat them away.
Die Hard
In the thriller Die Hard, actor Alan Rickman’s character falls backward off a building, and his facial expression is just too real. It turns out that this is more than really good acting – director John McTiernan helped out a bit.

Rickman practiced falling backwards onto an airbag several times. During rehearsals, the actor was dropped on the count of three. But when they actually filmed the scene, they dropped him at “one.” Rickman really was surprised when he was suddenly free-falling through the air.
Monster Squad
In Monster Squad, a little five-year-old girl stands between Count Dracula and the amulet that will allow him to take over the world. Dracula comes up to the child and lifts her up in the air, and the little girl starts screaming and crying in fear.

Well, no child actress is that good. Ashley Bank, who played the little girl, hadn’t yet seen Dracula in full makeup when they shot the scene. When she found herself face to face with his fangs and red eyes, she totally freaked out.
Godfather
In the last scene of The Godfather, Vito Corleone, played by Marlon Brando, is playing with his three-year-old grandson. In order to try to develop a connection with the little boy, Brando decided to goof around a little.

He took a piece of orange peel, put it in his mouth, and started growling like a monster. Instead of laughing, however, the child got really scared and started crying. Then Brando proceeded to comfort him. The little boy’s fear was unplanned, but it made it into the film.
Prometheus
Like Alien, science fiction movie Prometheus was directed by Ridley Scott, so maybe it should have been expected that the director would really try to scare the actors.

There is a scene in the movie when a monster shoots out of a corpse’s mouth. Unbeknownst to the actors, Scott had rigged up a device that would really shoot the monster out of the mask. When it happened, the actors were completely unprepared, and they really jumped in fright.
Maximum Overdrive
Author Stephen King made his directorial debut with Maximum Overdrive. During the making of the film, King believed that the best way to get believable performances from the actors was to actually scare them.

In a scene where a lawn mower is running out of control, King insisted on using a real lawn mower with the blades inside, even though the actors asked him not to. It was controlled with a remote so it couldn’t do any real damage, but the actors ran from it in true terror.
Roar
Considered to be the most dangerous film shoot in history, Roar tells the story of a family whose home is taken over by wild animals. It was shot over a period of 11 years, using real live animals including lions and other big cats.

Throughout the filming period, 70 members of the cast and crew, including stars Noel Marshall, Tippi Hedren, and her young daughter Melanie Griffith, were injured. The wounds suffered in the film were real, as was the actors’ fear.
Texas Chainsaw Massacre
The director of The Texas Chainsaw Massacre, Tobe Hooper, wanted the actors’ reactions to seem as genuine as possible.

So he kept Gunnar Hansen, the actor playing the main murderer, away from the others until they were really shooting a scene with him for the first time. When the characters first set eyes on the terrifying killer, they really were startled. Jerry, one of the characters, let out a squeal of fear, and it’s because he was actually scared.
Close Encounters of the Third Kind
Working with children can be tough, but they are a bit easier to scare than adults.

In Steven Spielberg’s science fiction film Close Encounters of the Third Kind, four-year-old Cary Guffey plays a little boy who gets abducted by aliens, and his horrified reactions are super believable – because they’re real. Spielberg asked the makeup guy to dress up as a scary gorilla and hide on set. When little Cary walked around the corner, the terrifying gorilla jumped out at him. It’s safe to say that he was genuinely shocked.
The Departed
Jack Nicholson is serious about the roles he plays. In gangster movie The Departed, Nicholson was completely in character, ad libbing and keeping the other actors alert. At one point during filming, Nicholson felt that co-star Leonardo DiCaprio wasn’t scared enough.

So, with permission from director Martin Scorsese, Nicholson took matters into his own hands. He brought his own shocking props including a gun, and pulled them out in DiCaprio’s face. So DiCaprio’s look of horror is completely authentic!