NIGHT vision. Found footage. Viral marketing. Hand-held realism. A film shot by its own cast. A movie made on a budget of next to nothing which goes on to be a worldwide hit. When it comes to cinema - and particularly horror movies - those tricks are everywhere today, right?

Well, those techniques wouldn't exist at all if it hadn't been for a low-low budget movie that is nearly 20 years old, but changed the nature of cinema forever: The Blair Witch Project.

First released in 1999, its sequel - Blair Witch - is about to hit screens just before Hallowe'en, picking up where the original ended. The anticipation among movie fans is huge - thanks in no small part to memories of just how influential the first film turned out to be.

In 1999, Daniel Myrick and Eduardo Sánchez’s independent horror flick was released amid a storm of hype. The movie was one of the first to exploit online marketing - and it did so ruthlessly.

Neil Hepburn from the Cameo cinema in Edinburgh calls the campaign “ingeniously simple”. In the late 90s, the power of the internet as a tool for advertising was still in its infancy. Chris Nials, founder of the London Horror Society - the UK's biggest club for horror fans - says: “Part of the reasons for The Blair Witch Project's success was the fact that it was released at an absolutely perfect time - before social media was commonplace.”

The movie's website - which still exists - was set up featuring 'true crime' style reports about the missing cast and crew.

Ian Rattray, co-director of the Horror Channel’s FrightFest, says of the film: “No one had done anything like this before... It was spellbinding.” Both the online marketing and opening titles claimed that three student filmmakers had disappeared in the Maryland woods, and that their footage had been found one year later.

Chris Nials, of the London Horror Society, says: “The ‘true story’ element of the frankly brilliant marketing campaign spread like wildfire, as folk didn't really have the ability to verify the rumours. All people heard was how American audiences were fleeing the cinema in terror at its apparent ‘realness’, which only built up the film's notoriety.”

The website builds on the mythology of the film and provides an entirely fictitious timeline of horror legends from Maryland. The “Aftermath” section of the site is full of phony interviews with private investigators, police officers and academics, all adding a sense of legitimacy.

Neil Hepburn from the Edinburgh Cameo recalls some more strategies used to market the film: “IMDB listed the cast as ‘missing, presumed dead’, and the filmmakers distributed flyers at film festivals, asking for information about the missing cast.”

The film easily crossed over from horror to mainstream - with run of the mill film-goers stunned (quite literally) by the movie's realism, made all the more unsettling by the use of hand-held cameras.

The film consists solely of footage shot by the cast on handheld cameras. When supernatural forces start to stalk the moviemakers, wildly jolting camera shots immerse the viewer in the action as if they were in the film.

The fact that this film had a very low budget, and was independently produced, was also remarkable for the time. People are still unsure about exactly how low the budget was, with estimates ranging from $20,000 to $75,000 - in Hollywood terms a budget of zero. Despite its frugal approach to funding, the movie grossed an astonishing $248 million worldwide, making it financially one of the most successful independent films of all time. Ian Rattray of FrightFest points out that now “small, no-budget films are used as a way into the film industry. The genre of horror is really the last genre of film where you can [do this]".

The Blair Witch Project spawned a near uncountable galaxy of imitators, trying to replicate its success by copying the film’s style, content, and marketing strategy. The Paranormal Activity movie franchise - worth a cool £1.5 billion - would quite simply never have been conceived had it not been for The Blair Witch Project. Chris Nials comments: “The Blair Witch Project was responsible for bringing the ‘found footage’ horror genre to the mass market, despite not actually being the first film to be shot in this style. That honour goes to the 1980's infamous classic Cannibal Holocaust.”

Fright Fest’s Ian Rattray says: “[The Blair Witch Project] inspired a whole generation of found footage films which came along in its wake.” Rattray points to JJ Abrams' “big-budget Cloverfield”, about New York residents fleeing a colossal monster in Manhattan, which also makes use of found footage, entirely shot on a home camcorder by the cast.

Importantly, the films influenced by The Blair Witch Project are not confined to the horror genre, especially when it comes to advertising. The campaign for The Dark Knight, Christopher Nolan’s Batman movie, began with a faux political campaign site for the character Harvey Dent. The advertisers even went as far as to create a fictional newspaper, The Gotham Times.

Prometheus also stole The Blair Witch Project’s online strategy. The Alien prequel’s marketing strategy involved a TED talk from the future, and a fake advert for an android, David 8, portrayed by Michael Fassbender.

Without doubt then The Blair Witch Project changed movies forever. With its sequel set to hit screens within the month, who knows what else will change in the weeks, months and years to come.

The 12 Scariest Scenes from Horror Movies

With the coming release of Blair Witch, horror fans are wondering whether the sequel can ever live up to its terrifying predecessor - which many critics say was the 'scariest movie ever made'. The Blair Witch Project has probably one of the most frightening scenes ever - without wishing to give spoilers, the 'guy standing in the corner of the room' scene was tailor-made to make audience scream and freak out. So, to celebrate the history of horror, here we give you a run down of 12 of the most stomach-churning, spine-tingling movie moments of all time.

UN CHIEN ANDALOU

During the infancy of cinema, surrealist artist Salvador Dali experimented with body horror, alongside director Luis Buñuel. Their 1929 film, Un Chien Andalou, plays with the idea of Freudianism, and in one of the most infamous scenes from the film shows a man slitting a woman’s eye with a razor. In fact, the eye belongs to a dead horse.

CAT PEOPLE

Val Lewton, a movie producer in the 1940s, was credited with the invention of the technique known as the “Lewton Bus” - and his classic horror movie Cat People is the film in which the trope originates. In one scene, shot ominously at night with spooky shadows, the audience is set up to believe the heroine is about to meet a rather unpleasant fate. Just at the moment when we think the killer is about to strike, a sudden shrieking noise fills the screen - guaranteeing a mass seat-jump from the audience. However, the noise is revealed to be nothing but a bus pulling up in the road. And that is the birth of the “Lewton Bus”.

LES DIABOLIQUES

Henri-Georges Clouzot’s 1955 film follows the fortunes of two women, Christina and Nicole, who together plot to kill the abusive Michel. Having placed the dead man in a bathtub, the women soon find that their plans are not going as well as they hoped. Accompanied by his wife Christina’s piercing screams, Michel rises from the bath-tub, staring with blank white eyes - in one of the most disturbing scenes in cinema.

PSYCHO

Alfred Hitchcock’s most famous films, with one of the most well-known soundtracks, almost didn’t have music accompanying the infamous shower scene. But that's actually not the most shocking scene in the film. That plaudit must go to the final scene, with Norman Bates, played by Antony Perkins, sitting in a police holding cell, grinning while a fly crawls over his face.

THE EXORCIST

What to pick? Vomiting? Horrifying acts with a crucifix? Twisty heads? This 1973 classic still has the power to terrify an audience. However, the one scene which stands out today as the creepiest of all wasn't even in the original film. The “spider-walk scene”, in which the possessed child crawls backwards down the stairs, was cut from the original theatrical release, due to the visible wires used to create the effect. New CGI-enhanced variants of the scene were shown in the 25th anniversary DVD edition.

DON’T LOOK NOW

Another 1973 masterpiece, Nicolas Roeg’s tale of grief was adapted from a short story by Daphne du Maurier. Following the death of their daughter in a drowning accident, a married couple move to Venice for work. In its most infamous scene - well, apart from the sex scene - husband, John, catches a glimpse of a dwarf wearing a red coat, similar to the coat which belonged to his daughter. It still has the power to give an audience group hysteria.

THE TEXAS CHAINSAW MASSACRE

In 1974, Leatherface burst onto cinema screens for the first time. His appearance was enough to send audiences into fainting-fits. We first see him emerging from the shadows, wearing a mask made of human skin. He dispatches an innocent victim with a hammer and drags the body off screen. It all lasts a matter of seconds - but left viewers shaken to their core.

JAWS

Another movie with a soundtrack as famous as its premise, Jaws caused a splash (no pun intended) in 1975 with its fearsome finned foe and plucky shark-hunters. When a human head, severed by the shark, floats up from a submerged boat, the audience is guaranteed a collective seat-jump and group scream.

THE SHINING

We have all seen Jack Nicholson’s head bursting through the bathroom door, and crying out, “Here’s Johnny!” This scene from The Shining has become a pop-culture legend. Although the film was originally met with mixed reviews when released in 1980, recent evaluations have cast it in a much more favourable light, elevating it to the level of classic. And the moral of the story is: don’t EVER build a hotel on an Indian burial ground.

SILENCE OF THE LAMBS

Although Antony Hopkins often steals the show, and his dinner, in this 1991 psychological thriller, one of the most tense scenes involves Jodie Foster’s character, Clarice stumbling through a dark basement while pursued by the serial killer Buffalo Bill. As Bill easily navigates the basement with his night-vision goggles, Clarice is at a distinct disadvantage. The audience, peering through Bill’s goggles, can see what Clarice cannot, and so knows exactly how much danger she is in.

REC

This 2007 Spanish horror movie owes a huge debt to The Blair Witch Project. There's plenty of terrifying moments: firemen falling to their deaths, a handcuffed woman eaten alive, life or death chases in a Barcelona tenement building, but perhaps the most unsettling scene is the final reveal of what lies behind the outbreak of violence. No spoilers.

UNDER THE SKIN

This extra-terrestrial/horror hybrid from 2014 was loosely based on the novel by Michel Faber, and brought to the screen by director Jonathon Glazer. The film stars Scarlet Johansson as a seductive alien who kidnaps men in Glasgow and the Highlands of Scotland. One of the scariest scenes involves Johansson luring a hapless man back to her lair, where he is submerged in a strange black liquid. In this liquid he can barely move and, soon, he completely dissolves. An eligible bachelor’s worst nightmare.