The Evil Dead is a horror movie that hasn’t just become extremely popular, but has been highly influential on the genre as a whole; even so, Sam Raimi’s film actually bears a lot in common with a 1970s film called Equinox to the point where some have gone as far to say he ripped it off.
Sam Raimi has become a leading name in the film industry, and helped kickstart the superhero movie trend way ahead of the curve. Raimi is responsible for some truly wonderful pieces of cinema, but The Evil Dead is an especially important film because it helped put him on the map. The Evil Dead also became what is considered by most to be the prototypical cabin in the woods horror movie. Many modern horror movies have borrowed from this simple structure of Raimi's movie, and a lot of horror's biggest genre conventions can be traced back to The Evil Dead and its sequel.
A major problem within the horror industry is that there's a lot of movies that just crib from lesser known films, but then don’t do anything new with the premise or property. There’s enough crossover of ideas in the horror genre that it can already be difficult to find original concepts that feel genuinely unique and aren’t just a reboot, sequel, or rip off. What’s surprising to hear is that Raimi’s very own The Evil Dead—a movie often cited as one of the most original in genre history—is, in fact, derivative of a movie that came out a decade earlier, which does share a lot in common with Raimi’s cabin in the woods film.
Directed by Jack Woods and Dennis Muren, Equinox came out in 1970, and features a story where a bunch of students are called together to a cabin to help investigate a foreboding religious text that contains incredible powers. It's not long until David and the rest of these students find themselves at the mercy of a slew of monsters that they've accidentally unleashed. The Evil Dead undeniably follows the same trajectory of this, but even though the films have the same larger idea, it’s the specifics where they diverge. Equinox doesn’t restrict itself to its cabin, and it features a war against the Devil himself, rather than the nondescript demon nature of Deadites. Equinox’s monsters are more mythological in nature; if any of Raimi’s films pull from Equinox, it would be Army of Darkness.
The two movies share similar ideas, but none of the same themes; Equinox operates more as a parable. Curiously, it’s the low-budget nature of both of these movies that makes them feel more connected to each other rather than any major plot overlap, but this fact also highlights another major difference between them. A major distinction between the two movies is how they both attempt to get creative with their budgetary restraints. The Evil Dead turns its malevolent force into an unseen nature that flies through the air to claim its victims, whereas Equinox creates actual portals to different dimensions where these stop-motion monstrosities let loose.
Equinox also had an extremely limited theatrical run that was mostly contained to drive-in theaters, so it stands to reason that Sam Raimi never even saw it, despite his cinephile nature. It’s worth addressing that, while Raimi has never cited the movie as an influence, there were still members of the Evil Dead crew who had seen the film, like Tom Sullivan, The Evil Dead's special effects and makeup artist. On the booklet of Equinox's Criterion DVD, Sullivan suggests that both Equinox and The Evil Dead are made by people who come from and embrace low-budget moviemaking, which is absolutely true. Besides any parallel thinking, The Evil Dead has evolved into a franchise that's so much bigger and more elaborate than where it started, it bears even less of a resemblance to Equinox—even if they both came from humble beginnings.