9 fascinating facts you didn't know about 'The Exorcist'

Five decades after its theatrical release, "The Exorcist" hasn't lost its power to compel audiences.

William Friedkin's "The Exorcist," arguably the greatest horror film ever made, is celebrating its 50th anniversary this year, and the franchise has returned to theaters with David Gordon Green's "The Exorcist: Believer." In honor of the sequel's release, here's a look back at Friedkin's original masterpiece and some fascinating, spooky facts about its creation.

The subliminal creepy face is from a makeup test

One of the scariest moments in "The Exorcist" is one of the most subtle: A face flashes on screen while Father Karras (Jason Miller) is dreaming. This was taken from footage of an early makeup test.

In the documentary "Leap of Faith," Friedkin explained the that first makeup test for Regan (Linda Blair) "was just [a] white face, dark eyes, [and] red lines under the face," but he didn't like this look for her. Months later, editor Bud Smith pointed out how shocking a frame from the makeup test looked when flashed on screen.

"It's not in the script," Friedkin noted. "I decided to put it in later."

Linda Blair and Ellen Burstyn were really injured

Blair recalled in an episode of "Cursed Films" that for the sequence where Regan thrashes back and forth on her bed, she was laced into a piece of equipment. But during one take, the lacing came loose, and "it fractured my lower spine," Blair said. "No, they didn't send me to a doctor. It is the footage that’s in the movie."

Similarly, when Chris MacNeil (Ellen Burstyn) falls after Regan slaps her, Burstyn injured her back. "I screamed in horrendous pain," she recounted in the documentary "The Fear of God," noting she was "furious" because Friedkin directed the cinematographer to "tilt the camera down on me" before calling an ambulance.

A man who appears in the movie was later convicted of murder

Paul Bateson, who briefly appears in "The Exorcist" as a radiology technician, was convicted of murdering a film reporter six years after the movie's release. His conviction, along with stories about numerous deaths connected to people who worked on "The Exorcist," bolstered its reputation as a "cursed" film.

The set was ridiculously cold

To make Regan's room cold enough so her breath would be visible, four air conditioners were used to bring the temperature on set down as low as 40 degrees below zero, according to the documentary "The Fear of God."

Friedkin drew from a tape of a real exorcism

According to Friedkin's director's commentary, he took the phrase "the power of Christ compels you" from audio of an actual exorcism performed at the Vatican, where these words were said repeatedly. Friedkin also revealed he took the "sound of the demonically possessed boy" from this tape and mixed it into the film.

The writer was previously known for comedy

Before writing the book "The Exorcist," and then the screenplay, William Peter Blatty was best known for writing comedies, including the "Pink Panther" sequel "A Shot in the Dark." According to the book "The Exorcist Legacy," Blatty wrote the novel after winning $10,000 on the Groucho Marx quiz show "You Bet Your Life" in 1961. The book and subsequent film "destroyed my comedy writing career, needless to say," Blatty noted in the documentary "Raising Hell."

The boy in the real case later worked for NASA

In 2021, months after his death at age 85, the real boy whose reputed demonic possession inspired the book and movie was identified as Ronald Edwin Hunkeler. After undergoing more than 20 exorcism rituals at age 14, Hunkeler went on to have a long career as a NASA engineer, according to The Guardian.

The vomit in the face surprised Jason Miller

When Regan vomits on Father Karras, the plan was for him to be hit in the sweater. But according to "The Fear of God" documentary, actor Miller was accidentally hit in the face, and this take was used in the movie. "My momentary reaction was I was a little pissed off," Miller recalled.

Friedkin fired a gun and smacked an actor to get a reaction

Friedkin would sometimes shoot an actual rifle on set without warning to capture a genuine surprised reaction from the actors, including for a moment where Karras is startled by a phone ringing, the director admitted in "Leap of Faith."

Similarly, before filming the scene where Father Dyer (William O'Malley) is shaken up while giving last rites to Karras, Friedkin smacked O'Malley in the face to help him get into character. "Afterward, he hugged me and thanked me," the director said, though he noted "techniques like that would not go over today."