Myrick and Sánchez conceived of a fictional legend of the Blair Witch in 1993. They developed a thirty-five page screenplay with the dialogue to be improvised. A casting call advertisement in Backstage magazine was prepared by the directors and Donahue, Williams, and Leonard were cast. The film entered production in October 1997, with the principal photography taking place in Maryland for eight days. About twenty hours of footage was shot and was edited down to eighty-two minutes.
In October 1994, film students Heather, Mike, and Josh set out to produce a documentary about the fabled Blair Witch. They travel to Burkittsville, Maryland, and interview residents about the legend. Locals tell them of Rustin Parr, a hermit who lived in the woods and kidnapped eight children in the 1940s. After spending the night at a motel, the students explore the woods in north Burkittsville to research the legend. Along the way, they meet two fishermen, one of whom warns them that the woods are haunted. He also tells them of a young girl named Robin Weaver who went missing in 1888. When she returned three days later, she talked about "an old woman whose feet never touched the ground." However, his companion is skeptical of the story. The students then hike to Coffin Rock, where five men were found ritualistically murdered in the 19th century, their bodies later disappearing. The group then camps for the night.
They move deeper into the woods the next day and locate what appears to be an old cemetery with seven small cairns and set up camp nearby. Later that night, they hear the sound of twigs snapping from all directions but assume the noises are from animals or locals. The following day, they attempt to hike back to the car, but are unable to find it before dark and make camp. That night, they again hear twigs snapping but fail to find the source of the noises.
At morning they find that three cairns have been built around their tent during the night, which unnerves them. As they continue, Heather realizes her map is missing and Mike later reveals he kicked it into a creek the previous day out of frustration, which prompts Heather and Josh to attack him in a rage. They realize they are now lost and decide simply to head south. They eventually reach a section where they discover a multitude of humanoid stick figures suspended from trees. That night, they hear sounds again, including the sound of children laughing among other strange noises. After an unknown force shakes the tent, they flee in panic and hide in the woods until dawn.
Upon returning to their tent, they find that their possessions have been rifled through, and Josh's equipment is covered with slime. As they continue, they come across a log on a river identical to one they crossed earlier. They realize they have walked in a circle, despite having traveled south all day, and once again make camp. Josh suffers a breakdown while holding the camera, taunting Heather for their circumstances and her constant recording of the events.
Heather and Mike awaken the next morning to find that Josh has disappeared. After trying in vain to find him, they slowly move on. That night, they hear Josh's agonized screams in the darkness but are unable to locate him. Mike and Heather theorize that Josh's screams are a fabrication by the witch in order to draw them out of their tent.
Heather discovers a bundle of sticks the next day, tied with a piece of fabric from Josh's shirt outside her tent. As she searches through it, she finds blood-soaked scraps of Josh's shirt as well as teeth, hair, and what appears to be a piece of his tongue. Although distraught by the discovery, she chooses not to tell Mike. That night, Heather records herself apologizing to her family, as well as to the families of Mike and Josh, taking full responsibility for their predicament.
They again hear Josh's agonized cries for help and follow them to a derelict, abandoned house containing symbols and children's bloody hand-prints on the walls. Mike races upstairs in an attempt to find Josh while Heather follows. Mike then says he hears Josh in the basement. He runs downstairs while a hysterical Heather struggles to keep up. Upon reaching the basement, something attacks Mike and causes him to drop the camera and go silent. Heather enters the basement screaming, and her camera captures Mike facing a corner. Something then attacks Heather, causing her to drop her camera and go silent as well. The footage continues for another moment and then ends.
Development of The Blair Witch Project began in 1993. While film students at the University of Central Florida, Daniel Myrick and Eduardo Sánchez came across the idea for the film after realizing that they found documentaries on paranormal phenomena scarier than traditional horror films. The two decided to create a film that combined the styles of both. After graduation, Myrick and Sánchez, along with Gregg Hale, Robin Cowie, and Michael Monello started the production company Haxan Films, derived from Benjamin Christensen's 1922 Swedish-Danish silent documentary horror film Häxan, whose English-language title is Witchcraft Through the Ages.
In developing the mythology behind the film, the creators used many inspirations. For instance, several character names are near-anagrams: Elly Kedward (The Blair Witch) is Edward Kelley, a 16th-century mystic, and Rustin Parr, the fictional 1940s child-murderer, began as an anagram for Rasputin. Viewers are told that the Blair Witch is, according to legend, the ghost of Elly Kedward, a woman banished from the Blair Township (latter-day Burkittsville) for witchcraft in 1785. The directors incorporated that part of the legend, along with allusions to the Salem witch trials and Arthur Miller's 1953 play The Crucible, to play on the themes of injustice done on those who were called witches.
The directors cited influences such as the television series In Search of..., and horror documentary films Chariots of the Gods and The Legend of Boggy Creek. Other influences included commercially successful horror films such as The Shining, Alien, and The Omen. Jaws was an influence as well, presumably because the witch was hidden from the viewer for the entirety of the film, forcing suspense from the unknown.
Pre-production began on October 5, 1997. In talks with investors, the directors presented an eight-minute documentary along with newspapers and news footage. The documentary was also aired on the defunct television series Split Screen hosted by John Pierson. The script began with a thirty-five page outline, with the dialogue to be improvised. Accordingly, the directors advertised in Backstage magazine for actors with strong improvisational abilities. There was a very informal improvisational audition process to narrow the pool of 2,000 actors.
According to Heather Donahue, auditions for the film were held at Musical Theater Works in New York City, and ads were placed in the weekly Backstage for an open audition. The advertisement noted a "completely improvised feature film" shot in a "wooded location". Donahue described the audition as Myrick and Sánchez posing her the question: "You've served seven years of a nine year sentence. Why should we let you out on parole?" to which Donahue was required to improvise a response. Joshua Leonard, also in response to audition calls through Backstage, claimed he was cast in the film due to his knowledge of how to run a camera, as there was not an omniscient camera filming the scenes.
Principal photography began on October 23, 1997. Most of the film was shot in Seneca Creek State Park in Montgomery County, Maryland, although a few scenes were filmed in the real town of Burkittsville. Some of the townspeople interviewed in the film were not actors, and some were planted actors, unknown to the main cast. Donahue had never operated a camera before and spent two days in a "crash course". Donahue said she modeled her character after a director she had once worked with, citing the character's "self-assuredness" when everything went as planned, and confusion during crisis.
During filming, the actors were equipped with a CP-16 and Hi8 video cameras provided by cinematographer Neal Fredericks, and given clues as to their next location through messages hidden inside 35 mm film cans left in milk crates found with Global Positioning Satellite systems. They were given individual instructions that they would use to help improvise the action of the day. Teeth were obtained from a Maryland dentist for use as human remains in the film. Influenced by producer Gregg Hale's memories of his military training, in which "enemy soldiers" would hunt a trainee through wild terrain for three days, the directors moved the characters a long way during the day, harassing them by night and depriving them of food.
The final scenes were filmed at the historic Griggs House, a 200-year-old building located in the Patapsco Valley State Park near Granite, Maryland. In late November 1999, the house was reportedly being flocked by fans of the film and took chunks from it as souvenir, which caused the township to order it to be demolished the following month. Filming concluded on October 31, Halloween.
After filming, twenty hours of raw footage was recorded which had to be cut down to two-and-a-half hours; the editing process took more than eight months. The directors screened the first cut in small film festivals in order to get feedback and make changes that would ensure that it appealed to as large an audience as possible. Originally, it was hoped that the film would make it on to cable television, and the directors did not anticipate wide release. The final version was submitted to Sundance Film Festival. After a surprise hit during its midnight premiere on January 25, 1999, Artisan Entertainment bought the distribution rights for $1.1 million. Prior to that, Artisan had wanted to change the film's original ending—in which Donahue screams in terror and finds Michael C. Williams facing a corner in the basement before being knocked over—as a number of test audiences were somewhat puzzled even though they admitted being scared with it. The directors and Williams traveled back to Maryland and four alternate endings were shot, one of which employed gory elements. Ultimately, they decided to keep the original, with Myrick explaining, "What makes us fearful is something that's out of the ordinary, unexplained. The first ending kept the audience off balance; it challenged our real world conventions and that's what really made it scary."
A list of production budget figures have circulated over the years, appearing as low as $20,000. In an interview with Entertainment Weekly, Sánchez revealed that when principal photography first wrapped, approximately $20,000 to $25,000 had been spent. Richard Corliss of Time magazine reported a $35,000 estimated budget. Other figures list a final budget ranging between $500,000 and $750,000. By September 2016, The Blair Witch Project has been officially budgeted at $60,000.
The Blair Witch Project is thought to be the first widely released film marketed primarily by the Internet. The film's official website featured faux police reports and "newsreel-style" interviews. These augmented the film's found footage device to spark debates across the Internet over whether the film was a real-life documentary or a work of fiction. During screenings, the filmmakers made advertising efforts to promulgate the events in the film as factual, including the distribution of flyers at festivals such as the Sundance Film Festival, asking viewers to come forward with any information about the "missing" students. The campaign tactic was that viewers were being told, through missing persons posters, that the characters were missing while researching in the woods for the mythical Blair Witch. The IMDb page also listed the actors as "missing, presumed dead" in the first year of the film's availability. The film's website contains materials of actors posing as police and investigators giving testimony about their casework, and shared childhood photos of the actors to add a sense of realism.
USA Today has opined that The Blair Witch Project was the first film to go viral despite having been produced before many of the technologies that facilitate such phenomena existed.
The backstory for the film is a legend fabricated by Sánchez and Myrick which is detailed in the Curse of the Blair Witch, a mockumentary broadcast on the SciFi Channel in 1999 prior to the release of The Blair Witch Project. Sánchez and Myrick also maintain a website which adds further details to the legend.
The legend describes the killings and disappearances of some of the residents of Blair, Maryland (a fictitious town on the site of Burkittsville, Maryland) from the 18th to 20th centuries. Residents blamed these occurrences on the ghost of Elly Kedward, a Blair resident accused of practicing witchcraft in 1785 and sentenced to death by exposure. The Curse of the Blair Witch presents the legend as real, complete with manufactured newspaper articles, newsreels, television news reports, and staged interviews.
The Blair Witch Project premiered on January 25, 1999 at the Sundance Film Festival, and had a limited release on July 14 before going wide on July 30 after months of publicity, including a campaign by the studio to use the Internet and suggest that the film was "a record of real events". The distribution strategy for the film was created and implemented by Artisan studio executive Steven Rothenberg. The film earned $1,512,054 in its limited release opening weekend. The film went on to gross $29,207,38 from 1,101 locations and placed at number two in the United States box office third opening weekend, surpassing the science fiction horror film Deep Blue Sea which cleared $19,107,643 weekend gross. The film secured its second place in its fourth weekend, behind another horror film The Sixth Sense, which cleared $26,681,262. The film descended at number three in its fifth weekend, at number five in its sixth weekend, and number eight in its seventh and eighth weekend during Labor Day. The film dropped out of the top-ten list in its tenth weekend until its last screening in 107 theaters in its seventeenth weekend, grossing $28,866 and placing in number sixty-three. By the end of its theatrical run, the film grossed $140,539,099 in the US and Canada in its total screening and produced $108,100,000 in other territories, having an overall gross of $248,639,099 (over 4,000 times its original budget). The Blair Witch Project was the tenth highest-grossing film in the US in 1999, and has since earned the reputation of becoming a sleeper hit.
Because the filming was done by the actors using hand-held cameras, much of the footage is shaky, especially the final sequence in which a character is running down a set of stairs with the camera. Some audience members experienced motion sickness and even vomited as a result.
The Blair Witch Project was met with generally positive reviews but polarized audiences on release. Rotten Tomatoes, a review aggregator, reports that 86% of 155 surveyed critics gave the film a positive review; the average rating is 7.7/10. The site's critical consensus states, "Full of creepy campfire scares, mock-doc The Blair Witch Project keeps audiences in the dark about its titular villain – thus proving that imagination can be as scary as anything onscreen". Metacritic rated it 81/100 based on 33 reviews, indicating "universal acclaim".
The Blair Witch Project's found footage film technique received near-universal praise by many and, though not the first to employ it, has been declared a milestone in film history due to its critical and box office success. Roger Ebert of the Chicago Sun-Times gave the film a total of four stars, and called it "an extraordinarily effective horror film". Peter Travers of Rolling Stone called it "a groundbreaker in fright that reinvents scary for the new millennium". Todd McCarthy of Variety said, "An intensely imaginative piece of conceptual filmmaking that also delivers the goods as a dread-drenched horror movie, The Blair Witch Project puts a clever modern twist on the universal fear of the dark and things that go bump in the night." Lisa Schwarzbaum of Entertainment Weekly gave a B grade, saying, "As a horror picture, the film may not be much more than a cheeky game, a novelty with the cool, blurry look of an avant-garde artifact. But as a manifestation of multimedia synergy, it's pretty spooky."
Conversely, Andrew Sarris of The New York Observer said, "Daniel Myrick and Eduardo Sánchez's The Blair Witch Project represents the ultimate triumph of the Sundance scam: Make a heartless home movie, get enough critics to blurb in near unison 'scary,' and watch the suckers flock to be fleeced. This fictional documentary within a pseudo-documentary form may be the most overrated, under-financed piece of film to come down the pike in a long time." A critic from The Christian Science Monitor said, "The concept is clever, suggesting a new way to build horror-movie suspense without much on-camera gore. The film would be better as a 30-minute short, though, since its shaky camera work and fuzzy images get monotonous after a while, and there's not much room for character development within the very limited plot." R. L. Schaffer of IGN gave it two out of ten, and described it as "boring – really boring", and "a Z-grade, low-rent horror outing with no real scares into a genuine big-budget spectacle".
The DVD for The Blair Witch Project was released on October 26, 1999 by Artisan, presented in a 1.33:1 windowboxed aspect ratio and Dolby Digital 2.0 audio. Special features include the documentary Curse of the Blair Witch, a five-minute Newly Discovered Footage, audio commentary, production notes, and cast and crew biographies. The audio commentary presents directors Daniel Myrick, Eduardo Sánchez, and producers Rob Cowie, Mike Monello and Gregg Hale, in which they discuss the film's production. The Curse of the Blair Witch feature provides an in-depth look inside the creation of the film.
The film's Blu-ray version was released on October 5, 2010 by Lionsgate. Best Buy and Lionsgate had an exclusive release of the Blu-ray made available on August 29, 2010.
Since its release, The Blair Witch Project has been widely regarded by many as an influence to an array of subsequent films similarly using the found footage concept and the conventions the film established. These include Paranormal Activity and REC (both in 2007), Cloverfield (2008), The Last Exorcism and Trollhunter (both in 2010), Chronicle, Project X, V/H/S , and End of Watch (all in 2012), and The Den (2013). Some critics have also noted the film as being strikingly similar to Cannibal Holocaust (1980), and The Last Broadcast (1998) in terms of basic plot premise and narrative style. Although Cannibal Holocaust director Ruggero Deodato has acknowledged the similarities of The Blair Witch Project to his film, he criticized the publicity that it received for being an original production; advertisements for The Blair Witch Project also promoted the idea that the footage is genuine. Despite initial reports by media outlets such as the New York Post and E! Entertainment that The Last Broadcast creators, Stefan Avalos and Lance Weiler, had alleged that The Blair Witch Project was a complete rip-off of their work and would sue Haxan Films for copyright infringement, they repudiated these allegations. One of the creators told IndieWire in 1999, "If somebody enjoys The Blair Witch Project there is a chance they will enjoy our film, and we hope they will check it out."
Film critic Michael Dodd has argued that the film is an embodiment of horror "modernizing its ability to be all-encompassing in expressing the fears of American society", acknowledging its status as the archetypal modern found footage feature, he noted that "In an age where anyone can film whatever they like, horror needn't be a cinematic expression of what terrifies the cinema-goer, it can simply be the medium through which terrors captured by the average American can be showcased". In 2008, The Blair Witch Project was ranked by Entertainment Weekly as number ninety-nine on their list of 100 Best Films from 1983 to 2008. In 2006, the Chicago Film Critics Association ranked it as number twelve on their list of Top 100 Scariest Movies. It was ranked number fifty on Filmcritic.com's list of 50 Best Movie Endings of All Time. In 2016, it was ranked by IGN as number twenty-one on their list of Top 25 Horror Movies of All Time, number sixteen on Cosmopolitan's 25 Scariest Movies of All Time, and number three on The Hollywood Reporter's 10 Scariest Movies of All Time. In 2013, the film also made the top-ten list of The Hollywood Reporter's highest-grossing independent films of all time, ranking number six.
American filmmaker Eli Roth has cited the film as a source of inspiration to promote his 2002 horror film Cabin Fever through the use of the Internet. The Blair Witch Project was among the films included in the book 1001 Movies You Must See Before You Die.
In September 1999, D. A. Stern compiled The Blair Witch Project: A Dossier. Perpetuating the film's "true story" angle, the dossier consisted of fabricated police reports, pictures, interviews, and newspaper articles presenting the film's premise as fact, as well as further elaboration on the Elly Kedward and Rustin Parr legends (an additional "dossier" was created for Blair Witch 2). Stern wrote the 2000 novel Blair Witch: The Secret Confessions of Rustin Parr, and revisited the franchise with the novel Blair Witch: Graveyard Shift, featuring all original characters and plot.
A series of eight young adult books entitled The Blair Witch Files were released by Random subsidiary Bantam from 2000 to 2001. The books center on Cade Merill, a fictional cousin of Heather Donahue, who investigates phenomena related to the Blair Witch in attempt to discover what really happened to Heather, Mike, and Josh.
In July 1999, Oni Press released a one-shot comic promoting the film, titled The Blair Witch Project #1. Written and illustrated by Cece Malvey, the comic was released in conjunction of the film. In October 2000, coinciding with the release of Book of Shadows: Blair Witch 2, Image Comics released a one-shot called Blair Witch: Dark Testaments, drawn by Charlie Adlard.
In 2000, Gathering of Developers released a trilogy of computer games based on the film, which greatly expanded on the myths first suggested in the film. The graphics engine and characters were all derived from the producer's earlier game Nocturne.
The first volume, Rustin Parr, received the most praise, ranging from moderate to positive, with critics commending its storyline, graphics and atmosphere; some reviewers even claimed that the game was scarier than the film. The following volumes, The Legend of Coffin Rock and The Elly Kedward Tale, were less well received, with PC Gamer saying that Volume 2's "only saving grace was its cheap price", and calling Volume 3 "amazingly mediocre".
The Woods Movie (2015) is a feature-length documentary exploring the production of The Blair Witch Project. For this documentary, director Russ Gomm interviewed the original film's producer, Gregg Hale, and directors Eduardo Sánchez and Daniel Myrick.
A sequel entitled Book of Shadows was released on October 27, 2000; it was poorly received by most critics. A third installment announced that same year did not materialize.
On July 22, 2016, a surprise trailer for Blair Witch was revealed at the San Diego Comic-Con. The film was originally marketed as The Woods so as to be an exclusive surprise announcement for those in attendance at the convention. The film, distributed by Lionsgate, was slated for a September 16 release and stars James Allen McCune as the brother of the original film's Heather Donahue. Directed by Adam Wingard, Blair Witch is a direct sequel to The Blair Witch Project, and does not acknowledge the events of Book of Shadows: Blair Witch 2. However, Wingard has said that although his version does not reference any of the events that transpired in Book of Shadows, the film does not necessarily discredit the existence of Book of Shadows: Blair Witch 2. In September 2016, screenwriter Simon Barrett explained that in writing the new film, he only considered material that was produced with the involvement of the original film's creative team (directors Daniel Myrick and Eduardo Sánchez, producer Gregg Hale, and production designer Ben Rock) to be "canon", and that he did not take any material produced without their direct involvement—such as the first sequel Book of Shadows or The Blair Witch Files, a series of young adult novels—into consideration when writing the new sequel.