Based on a true story. Five simple words that can turn a horror movie from mildly frightening to blood-curdingly terrifying. The neat little statement, whether true or not, blurs the line between fact and fiction.
It suggests that the stuff of nightmares can occur in waking life. It says that evil is in our midst and not just in a screenwriter's mind. In short: it scares the utter bejaysus out of us.
Forget suspense-building music and primal screams, just add these five words to your opening credits and you'll whip your audience into a terrified frenzy. Horror filmmakers are fast realising the impact that purported reality can have on audiences. Take 2008's The Strangers, the story of a couple who are terrorised by a masked cult when they spend a weekend in a remote country getaway. It was marketed as being "inspired by a true story", piquing the interest of audiences.
Needless to say, the claim generated huge interest and theories about the real-life events that it centred upon abounded on the internet. However, when pressed, the director could only recount a childhood tale about a neighbourhood burglar. This particular true story was inspired by the marketing department.
Would the original Texas Chainsaw Massacre have been so popular were it not marketed as a true story? The well-trodden myths about the film's alleged authenticity were a mark in time for film marketing as much as film innovation.
Likewise, would The Exorcist have lingered in the public consciousness had urban myths not been circulated about the 'cursed' production: a series of strange events that took place during filming and director William Friedkin's claims that a priest was brought in to bless the set?
When horror collides with reality the results are cataclysmic. In many ways these seminal films paved the way for the latest horror genre: point-of-view (POV) and mockumentary horror films. These faux documentaries purport to be real-life footage of chilling events and they are becoming the most popular vehicle for horror films.
[REC] 2, which opens today, is a continuation of the first film, starting just minutes after the climax of the original. A Spanish SWAT team arrive at a quarantined building to discover the virus inside is, in fact, caused by demonic possession. It bears all the hallmarks of the cinema verite style: gritty footage, shaky camera work and improvisation.
That the sequel of a cult Spanish movie can gain a major cinema release speaks volumes about the increasing popularity of the camcorder-horror genre. In 2008, Quarantine, a US remake of the original, was released and [REC] undoubtedly influenced director Eli Roth's soon-to-be released camcorder horror, The Last Exorcism.
The Blair Witch Project in 1999 was the first camcorder horror movie to gain international renown. The mockumentary is supposedly the recovered footage of three young filmmakers who went missing while making a documentary about a local legend known as the Blair Witch.
A rumour spread that The Blair Witch Project cost just $20,000 to make. However, the directors later conceded that after taking the film to Sundance, staging a series of reshoots and an extensive marketing campaign, the budget was closer to $750,000.
Paranormal Activity, a camcorder movie which centres on a young couple, Katie and Micah, who are haunted by a supernatural presence in their home, was said to have cost just $11,000 making it one of 2009's most profitable movies. Likewise, its makers didn't account for the viral-marketing budget, which some quarters say brought the overal spend well over the million-dollar mark.
The success of the camcorder genre is largely down to marketing campaigns that suggest that the faux recovered footage is, in fact, authentic. The result is that movie makers are making increasingly exaggerated claims. The Fourth Kind, which claimed to be based on true stories of alien abductions in Nome, Alaska, featured what were alleged to be actual clips and records made by psychologist Dr Abigail Tyler.
Late last year Universal Pictures agreed to make a $20,000 contribution to the Alaska Press Club "to settle complaints about fake news archives used to promote the movie".
"Universal acknowledged that they created fake online news articles and obituaries to make it appear that the movie had a basis in real events," read the statement.
As public demand peaks, the themes of this genre are becoming grittier. Take The Poughkeepsie Files, a film which never quite made it past the festival circuit. The disturbing mockumentary claims to be the chilling home movies of a serial killer's crimes found when the police raided his house.
Filmgoers have become desensitised to the predictability of traditional horror movies which often follow a film-by-numbers approach. The camcorder horror genre turns jaded audiences into voyeurs placing them in the middle of the action. It reflects a broader trend in filmmaking. Reality programming is dominating television land. DIY YouTube videos are an essential part of popular culture. The mockumentary, once a sub genre, is gaining supremacy in the comedy world.