When you go to see a horror film, there is a part of you that likes to think this is just fiction and is not based on any kind of reality but you know that old saying, there is no smoke without fire. Well, that’s true. Here are seven horror films that were based on true stories.

1. The Exorcist

The film is often cited as one of the most terrifying and rightly so, when Regan MacNeil starts acting incredibly strange, her mother calls in the local priest to perform an exorcism when all other means of help are exhausted. Based on a book by William Peter Blatty, The Exorcist tells the true story of an exorcism that was performed on a 13-year-old boy from Maryland. The details are a little more hazy now, perhaps to protect his identity but he went on to live a normal life.

2. A Nightmare on Elm Street

Everyone is familiar with the frightening story of Freddy Krueger, a child murderer who comes back to haunt the children of the people who killed him. However, director Wes Craven based the films on a series of articles he read about some men in Laos, Cambodia who were refusing to go to sleep as they were being attacked in their dreams. One man in particular passed out while watching television, was carried to bed and during the night began screaming and thrashing around. By the time his family got to him, he was already dead.

3. Child’s Play

A possessed doll wreaks havoc on a family after he is given to a child for his birthday. However, Chucky is based on the true story of a voodoo doll who was given to Key West painter Robert Eugene Otto by a Jamaican nurse. Otto’s family complained that they heard screaming during the night and that things would randomly go missing from his room. After his death, the new family who moved in to the house claimed the doll moved and was trying to kill them. Robert the Doll even has his own website.

4. The Conjuring

The story of a family who are haunted in the new farmhouse they move in to is freakishly based on a true story. Roger and Carolyn Perron and their five daughters were haunted by a spirit who would stink of rotten flesh and levitate beds at 5.15am. The family called in paranormal investigators, Ed and Lorraine Warren, to help rid them of the demon. Lorraine remained an official consultant on the film and the Perrons stand by the events, claiming most of the film is pretty accurate.

5. The Hills Have Eyes

Another of the Craven films which is loosely based on a true story. The Hills Have Eyes revolves around a family who are ambushed in the middle of nowhere by a group of cannibals. However, the true story originates from Scotland where a family headed by Sawney Bean, began to live in the caves and turned into cannibals. By the time they were hunted down and captured, the family numbered 48 in total and were responsible for the deaths of about 1000 people.

6. Psycho

Yes, you may freak out anytime you meet a man who is remotely attached to his mother in future but Norman Bates, the freaky motel owner who kills women who stay there, was actually based on Ed Gein, a Wisconsin man who was arrested for murdering 2 women and digging up countless others who he thought resembled his mother. He skinned the bodies to make lamp shades and a “woman suit” in the hopes of becoming a woman.

7. The Entity

If you haven’t seen the Entity yet, you really need to watch this one. Revolving around a woman who experiences attacks by a demon she claims is the Devil, the film is positively terrifying. The true story originates in 1974 when paranormal researchers Kerry Gaynor and Barry Taff investigated the case of Doris Blither, who claimed she was physically and sexually assaulted by an entity. Objects would move, floating lights and they even saw a human apparition. Not frightening, not frightening at all.