A mong its many other sick-making, swamp-stirring gifts to the world, Wes Craven's debut feature, The Last House on the Left, boasted one of the great film-poster taglines: "To avoid fainting, keep repeating to yourself: 'It's only a movie … it's only a movie … it's only a movie."
The film was released in 1972, and that slogan became Craven's mantra. He spent the next four decades stretching our understanding of that four-letter word - 'only' - to its limit, like a torturer tightening his victim on the rack.
From The Last House on the Left to A Nightmare on Elm Street, Scream and beyond, Craven used his films' status as horror - that low, disreputable genre, perhaps never lower and more disreputable than it was in the early 1970s when Craven first broke ground in it - to carry off flourishes of concept and craft that would be impossible in a more respectable mode of filmmaking. His films may have been only movies, but there was nothing only about them.
Craven was inspired to make The Last House on the Left by a viewing of Ingmar Bergman's ultra-austere medieval tragedy The Virgin Spring, in which a young maiden is gang-raped and left for dead, before being avenged by her mother and father - devout Christians plunged into a Hobbesian hell of nasty, brutish retribution.
Craven ditched Bergman's period setting and mythic overtones and retold the story in the immediate present: the girl (and her friend) are now on the way to a concert, and their rapists are escaped criminals rather than goat-herders. But the parents' revenge - boundless, blood-drenched madness erupting from two formerly respectable, middle-class adults randomly pushed over the edge - remained constant.
"Horror films don't create fear, they release it," Craven would say years later, in an interview for the documentary Fear in the Dark, and The Last House on the Left set loose industrial quantities of the stuff into an already febrile atmosphere.
In America, the fall of Richard Nixon, the Vietnam War and the ongoing civil rights struggle meant the old power structures were no longer to be trusted, and it was the new breed of horror filmmakers, like Craven, George A Romero (in The Night of the Living Dead) and Tobe Hooper (in The Texas Chain Saw Massacre), who allegorised that malaise in order to better pick through it.
In these films, entrenched authority was incompetent and/or corrupt - and the traditional, nuclear family unit had curdled beyond recognition. Mum, dad and the kids had transformed into the clan of slavering cannibals in Craven's second film, The Hills Have Eyes, while the nice folks from the local church became the community of weird religious ascetics in Deadly Blessing.
Unlike the sensual Hammer movies and the creature features that had reigned supreme at the box office beforehand, Craven's monsters often didn't creep out of castles or beam down from outer space. They just sauntered down the street and opened your front door. They were us.
No wonder his work struck a nerve. The Last House on the Left was banned in the UK in 1974, then banned again under the 'video nasty' ordinances of the early 1980s, and remained so until 2002 - though it was only released in its original, uncut form in 2008.
Meanwhile, Craven kept busy, changing horror as he went. In 1984, A Nightmare on Elm Street - the film that launched the big-screen career of Johnny Depp - introduced Freddy Krueger, a scorched, claw-clinking serial killer who prowls his teenage targets' bad dreams.
Freddy was the spirit of a child-murderer who had been burnt alive by a vigilante mob, and his scarred face, striped jumper and metal tendrils made him one of the most memorable of all horror monsters.
But it's the film's parents - a gaggle of pill-popping, booze-guzzling absentee deadbeats - who prepare his stalking ground of unquiet sleep.
The concept, Craven said, came from his own youth in Cleveland - specifically an Elm Street cemetery and a homeless man that inspired Krueger's look.
"There is something about the American dream, the sort of Disneyesque dream, if you will, of the beautifully trimmed front lawn, the white picket fence, mom and dad and their happy children, God-fearing and doing good whenever they can," Craven once said.
"And the flip side of it, the kind of anger and the sense of outrage that comes from discovering that that's not the truth of the matter, that gives American horror films, in some ways, kind of an additional rage."
The film ran with the bone-freezing maxim set down by John Carpenter in his 1978 grandfather-of-the-slasher-movies, Halloween - that there was nothing more sinister than an American suburb at twilight - and reinvigorated horror for a decade to come.
After Nightmare came a run of imaginative one-offs, including The Serpent and the Rainbow in 1988, a zombie thriller that threw off the genre's by-then well-established rules and themes to delve into its voodoo origins, and perhaps the best of Craven's less-celebrated films.
He dabbled in postmodernism too, first in 1994's New Nightmare, in which Freddy Kruger haunted the stars of the Nightmare on Elm Street franchise, and then again, two years later, in another genre-changing masterpiece, Scream.
With its frenzied knifeman in a billowing cloak and Munchian mask, carving American middle-class lives into slices, it was an archetypal slasher movie - except it was set in a world in which both killer and victims were au courant with the laws of slasherology, and used that knowledge to their advantage.
Three more Scream films followed, each dissecting horror-movie trends - sequels, remakes, franchises - but came interspersed with fresh ideas, including the underrated Red Eye, and his only feature made outside the horror genre, the inspirational teacher fable Music of the Heart, for which Meryl Streep was nominated for an Oscar.
That was as close as Craven came to mainstream industry acceptance - and notably, it was one of his least accomplished films.
His real legacy is built on that understanding of horror as something that could galvanise you against true fear: at their best, his films were like immunisations, that left you stronger and better-equipped to deal with the real world at its vilest.
We may have been his monsters, but we were also his heroes and heroines: bloody and brutalised, but limping out of the killer's clutches, towards the light.
"He was a consummate filmmaker and his body of work will live on forever," said Weinstein Co. co-chairman Bob Weinstein, whose Dimension Films produced Scream.
"He was truly an old-school director," Craven's genre contemporary John Carpenter said on Twitter. "Wes was a great friend, fine director and good man."
Wesley Earl "Wes" Craven was born in Cleveland on August 2, 1939, to a strict Baptist family. He earned a master's degree in philosophy and writing from Johns Hopkins University and briefly taught as a college professor in Pennsylvania and New York, but his start in movies was in pornography, where he worked under pseudonyms.
Director Edgar Wright, who counts Craven as one of his influences, reflected on the legacy of his films in a tribute on his website.
"The first Nightmare quickly became a landmark horror movie and what distinguished it then is what still marks it out as a classic now. It's the sheer twisted imagination of the premise; the idea of lucid waking nightmares bleeding into the real world makes Freddy Krueger a much more formidable and interesting foe than any of his slasher rivals," Wright wrote.
The formula would work again for Craven with Scream, albeit with an added layer of self-aware spoof. By 1996, the Craven-style slasher was a well-known type, even if it wasn't always made by him. He had no involvement with many of the Elm Street sequels.
Scream, written by Kevin Williamson and starring a cast including Drew Barrymore and Neve Campbell, played off of the horror clichés Craven helped create. It hatched three sequels, all of which Craven directed.
Courteney Cox, who appeared in four of the Scream films, said on Twitter that the world had lost a great man, "my friend and mentor, Wes Craven." Her co-star Rose McGowan echoed the sentiment, writing that "a giant has left us."
Craven was also a published author (the 2000 novel The Fountain Society) and an ardent bird conservationist, serving as a long-time member of the Audubon California board of directors. He recently penned a monthly column 'Wes Craven's The Birds' for Martha's Vineyard magazine.
He was active until his death. Craven had numerous television projects in development, including a new Scream series for MTV.
He was an executive producer of the upcoming film The Girl in the Photographs, which is to premiere in September at the Toronto International Film Festival. In a statement, Craven's family said he died in his Los Angeles home, surrounded by family, after battling brain cancer. He is survived by his wife, producer Iya Labunka, a son, daughter and stepdaughter.
In 2010, he told The Los Angeles Times: "My goal is to die in my 90s on the set, say, 'That's a wrap,' after the last shot, fall over dead and have the grips go out and raise a beer to me."