No matter how scary a horror film is (and no matter how many jump scares it throws at the screen, how many weird masks its characters wear, or how many shadowy figures slink around in the background for no discernible reason), there’s one simple way to instantly bolster its fear factor: tell people it’s “based on a true story.” Horror features have long been linked up with “true” stories – and though they sometimes really are based in reality, it’s hard to deny how powerful even the lingering possibility that they could maybe be true helps to make things feel just that more horrifying.

Even ‘Psycho,’ which didn’t directly bill itself on being based on real events, was based on Robert Bloch’s book of the same name, which was loosely inspired by the gruesome exploits of serial killer Ed Gein (the same murderer who also partially inspired Leather Face from ‘The Texas Chain Saw Massacre’ and Buffalo Bill from ‘Silence of the Lambs,’ among others). Terror classic ‘The Exorcist’ draws from the well-known 1949 case of a possessed boy known by the pseudonym “Roland Doe” (the Catholic Church eventually granted him an exorcism, a fraught one that mirrors Regan’s quite significantly), and even the nightmare-on-the-open-seas that is ‘Open Water’ was pulled from a real life occurrence that happened in 1998.

Tacking on a “based on a true story” tag has always helped bolster the scare factor of horror films, but its usage has become increasingly more frequent (and less fact-based) in recent years. Just because a film boasts about its real world roots doesn’t mean it’s always true. What’s really scary is how often it’s not.

Terrifyingly True Stories

This week’s new release, ‘Deliver Us From Evil,’ purports to be based on true events – hell, the film’s poster even boasts that it’s “inspired by the actual accounts of an NYPD sergeant,” the kind of wording that practically screams, “look how reliable this sounds, despite its vague wording!” Turns out, the feature really is based on the experiences of former cop Ralph Sarchie, a retired NYPD vet who turned his attentions to a new career as a demonologist. The Scott Derrickson film is based on Sarchie’s book ‘Beware the Night’ and it even goes so far to bill itself as a biopic. Still, your mileage may vary on this one, depending on how much stock you put into Sarchie’s claims. If nothing else, the guy has dedicated his life to investigating paranormal occurrences.

Deliver Us From Evil
Eric Bana in 'Deliver Us From Evil' / Screen Gems

Similarly, last year’s monster hit ‘The Conjuring’ is also based on real events – if you believe that there is such a thing as demonic possession, poltergeists, and ghosts. Based on one of Ed and Lorraine Warren’s most famous cases, if even just one tidbit from the film is true, it’s enough to give anyone nightmares for years. The Warrens investigated the case of the Perron family back in 1971, ultimately coming to the conclusion that it was indeed haunted by a 19th century witch. Still, she’s not even the most terrifying part of the film – that would be the Annabelle doll which, yes, still lives at the Warrens’ Occult Museum in Connecticut and is about to get her very own film (even if she doesn’t look a thing like her on-screen portrayal).

Stretching for Scares

The Warrens’ rich case history has inspired plenty of other films, too, most notably the 2009 scarefest ‘The Haunting in Connecticut,’ which alleges to be based on the 1986 Carmen Reed Snedeker case, which certainly did include some weird occurrences in a house in, yup, Connecticut. The fictionalized account of the story isn’t a fully fact-based one, though, as author Ray Garton (who wrote a book about the Snedeker case) has disavowed the film, while Lorraine Warren reports that the feature doesn’t even touch upon the full terror of the real case.

Exorcism of Emily Rose
Jennifer Carpenter in 'The Exorcism of Emily Rose' / Screen Gems

Also in the paranormal realm, ‘The Exorcism of Emily Rose’ pulled from a true story to craft a film that’s both more fictionalized and far less impressive than its source material. The 2005 Scott Derrickson film is loosely based on the true story of Anneliese Michel, a German woman who died after a Catholic exorcism. No, there was no actual “Emily Rose.”

Fiendish Folk Tales

Sometimes, all a horror film needs for the “based on true events” tag is a single object, as is the case with 2012’s ‘The Possession,’ which uses the very existence of a dybbuk box to craft an entire narrative. The dybbuk box was coined in 2003 following an eBay auction of a wine cabinet which was said to be haunted by a dybbuk, a malicious ghost believed to be the dislocated soul of a dead person (and comes from the Hebrew work for "the act of sticking"). While numerous owners of that particular box claimed mysterious phenomena, the final owner apparently worked with rabbis to "seal the box" and has it stored in an undisclosed location. But, any suggestion that a dybbuk has actually possessed anyone (or exists outside of one lone eBay auction) is pure fiction.

Frighteningly Fake

This year’s ‘The Quiet Ones’ sure sounds like it could be real, but don't get caught up thinking that this one is the real deal. The John Pogue film is simply based on the 1972 Philip experiment, a parapsychology experiment the involved a group of people attempting to invent a ghost. Did you even remember that plot point from the film?

Amityville Horror
Ryan Reynolds in the 2005 'Amityville Horror' remake / MGM

Elsewhere in the horrorsphere, the entire ‘Amityville’ series (which kicked off 1979, was remade in 2005, and has a new film lined up for 2015) was long ago proven to be nothing more than a cleverly crafted hoax, though few people realize that one of cinema’s most well-known “true” tales just doesn’t shake out. At least ‘The Amityville Horror’ and its spinoffs were somewhat based in fact (a whole family was actually murdered in the house everyone claimed was haunted), whereas Bryan Bertino’s ‘The Strangers’ is pretty much just based in memory, and a kind of flimsy one at that. The filmmaker claims it was inspired by a childhood memory he had of strangers (naturally) who knocked on doors in his neighborhood and then robbed homes that didn’t have anyone home (which isn’t at all like the film – which is about masked killers who murder people who do answer their doors).

What’s scary than horror film fictions? Well, how about some real life events?

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