The Hardest Horror Movies To Watch More Than Once

For all of the terror they instill in us, horror movies are generally a lot of fun to watch. They wouldn't have the longevity they do on an individual basis, much less that of the genre, if they weren't. Nonetheless, for every horror flick that gets picked up for annual rewatches and movie nights with friends, there's another that isn't quite as easy to watch a second, third, or fourth time. 

Some of these movies are tough to go back to because they depict violence too extreme for most viewers. Others go to emotional extremes that aren't nearly as fun to revisit as others. And some are totally fine up until a particularly horrifying ending (consider this your spoiler alert). Whether due to excessive gore or devastating endings, some horror films are really only meant to watch once; with that in mind, we've put together a grim and grisly list of entries in the genre that aren't nearly as easy to revisit after the end credits roll.

The exceedingly gruesome modern genre that has come to be known as "torture porn" got its unofficial start with 2004's Saw, but it hit its artistic apex (or nadir, depending on who you ask) with 2008's Martyrs. It's a difficult film to watch on content alone, with characters experiencing every kind of torture imaginable, from being beaten to being flayed alive. 

But it's the intent behind that torture and the overall thematic arc of the film—the search for forbidden knowledge and what finally possessing that knowledge can do to the human mind—that truly makes Martyrs a difficult film to get through. It builds to a hopeless ending implying that what waits for humans after death is either too horrible to know or nonexistent, simply a void. It's an experience, and one genre fans should absolutely partake in, but it is an exhausting one.

Not to undersell how effective a good old fashioned masked murderer can be, but there are few things in the realm of horror more terrifying than a film that effectively examines the monstrosities that human beings are capable of when indoctrinated under a system of belief. No film has ever done this as effectively as the grandfather of the slow-burn horror film, The Wicker Man. 

It's the rare genre entry that contains not a single fakeout jump-scare, or even a non-deceptive one for that matter. For the majority of its running time it's a tense but quiet thriller that builds slowly but surely to an inevitable and horrifying climax. And it's not until after that climax has played out and the credits are rolling that fear grips the viewer and doesn't let go for quite some time. It's an ending that recontextualizes everything that came before it, and while that's usually the sort of ending that merits a rewatch, it's not the case with The Wicker Man. It's far more likely to leave viewers too unsettled by what they've just seen to revisit it.

While films based around revenge almost necessitate the depiction of some horrid, inhumane act, few are quite as repulsive as that which is depicted in I Spit on Your Grave. The film is the story of a woman out for blood after being raped and left for dead in the woods by a group of men. Make no mistake, the men get what they deserve. Each dies bloodier than the last as she makes her way down her list. But in order to get to that point in the movie, the viewer has to sit through an excruciatingly long scene depicting the very realistic sexual assault of a woman.

Sexual assault is subject matter that will never be comfortable to sit through in any film, but it's depicted so brutally in I Spit on Your Grave that it borders on unnecessary. Even die-hard fans of exploitation film will likely find themselves uncomfortable with the idea of sitting through this one a second time. It's a hallmark of the genre for the same reasons it's near impossible to watch more than once. 

Even without its twist ending, Karyn Kusama's The Invitation would be uncomfortable to sit through a second time. The film sets out to put the nuance of interactions between lapsed friends under a microscope. Through a few hours spent at a tense dinner party it analyzes the minute intricacies of every awkward exchange between characters and explores the efforts people will go through to maintain face and stifle survival instincts when cordial social interactions go to places they shouldn't. 

Furthermore, it's a stunningly poignant meditation on grief and what people will do to cope with loss. These themes are explored intricately and stunningly, but they're so heavy that a second viewing is likely out of the question for most moviegoers. And this is all before the film's third act, which features the host couple trying to murder their friends and then kill themselves in the name of a mysterious spiritual group they've joined. All in all, it's an immaculate film that is probably best left alone after a single viewing.

It likely won't come as a shock given the film's title, but Cannibal Holocaust is one of the most infamous movies of all time, regardless of genre. It may not have been the first film to trade entirely on the promise of violence and mutilation but it certainly did it better and more excessively than any film had at the time. It's a cornucopia of sexual assault, dismemberment, and animal violence (some of which is totally real). 

There were even longstanding rumors that it depicted actual murder, resulting in the arrest of director Ruggero Deodato, though those allegations thankfully ended up being false. Connoisseurs of exploitation cinema are practically required to give Cannibal Holocaust a watch at some point. But it takes a moviegoer with a VERY high tolerance for gore and simulated depravity to make this a movie they revisit after the first time around. 

There are points at which Lake Mungo hardly feels like a horror film. Rather, the imitation-documentary plays out as a look into how the death of a loved one can devastate the people around them over time. There are supernatural elements to the film and some great frights to be had, but they're comparatively sparse across the movie's hour and a half running time. Those scares aren't what will keep viewers from coming back for a second viewing, though. That falls entirely on the subject matter. 

By staging the film as a fake documentary with no well-known actors to damage the audience's suspension of belief, director Joel Anderson amplifies the tangibility of the emotional devastation the Palmer family is experiencing after the death of their daughter Alice. That the supernatural aspects of the plot play directly into the emotions Anderson is exploring (the idea being that the ghost of Alice is simply trying to provide her family with the closure they're failing to find) only heightens this. 

Lake Mungo is a tremendous film, but one that deals with some very heavy subject matter. One might not find themselves inclined to give it a second watch, due not so much to the scares it provides but the realism with which it depicts an extremely trying experience that many viewers may find themselves all too familiar with.

While James Wan's Saw is often pointed to as the film that kickstarted torture-centric horror as a genre, Hostel is the movie responsible for stripping away any of its pretense and really making it what it is today. Director Eli Roth's plot revolves entirely around mutilation and dismemberment. Its story cuts directly to the chase when it comes to this, with the story centering around a secretive organization that provides clients possessing amply-sized wallets to torture kidnapped tourists in Europe.

While other genre staples like Saw and Martyrs seem to use torture as a means to explore, respectively, a genuinely intriguing plot or heavy thematic questions about human nature, Hostel makes no excuses for what it is. It's a movie about torture and pain, and Roth expects the audience to enjoy it. To be fair, there's a good chance they will. The film is a goldmine for gore fanatics and the practical effects utilized are top notch. But at the end of the day, it's a movie about people being physically ripped to shreds. In its defense, it depicts those horrors better than just about any other "torture porn" film. It was even successful enough to spawn not one but two sequels. 

But unless you're the kind of viewer who specifically enjoys gore effects in horror, you might not find yourself wanting to watch Hostel more than once. 

There's a good chance you haven't heard of Threads, and that may be a good thing. The film aired as a TV movie in Britain in 1984, granting it a relatively smaller audience than something theatrically released. Nonetheless, it warrants a place on this list on the merit of being one of the more disturbing TV movies of all time. The film depicts the aftermath of a nuclear holocaust on a working-class community and the general long-term effects of nuclear war. The imagery is astonishingly graphic and grim, and the film's message isn't exactly the cheeriest. Nuclear war is a far more direct and real horror than zombies or vampires, and the film isn't subtle in its parable. That the film is done in the style of a documentary only adds to its gritty, horrific realism. Even with the era in which the film was made now having long since passed, Threads is a rough, rough watch.