A horror movie that fails to make you scared is worse than bad. There's something embarrassing about watching it, akin to the feeling of having to turn down the advances of a well-meaning but unsexy friend.
It seems to me that there are five basic characteristics of a scare fail, though I'm open to the idea that there may be more. Humiliation knows no bounds, after all. Allow me to elaborate.
Failure of the Monster
An ill-conceived or shabbily-constructed monster is perhaps the most common source of scare fail. Possibly the worst offender - at least in recent memory - is The Happening, a monster movie whose "monster" was basically wind in trees. Pretty trees. Not "I rape you" trees like in Evil Dead, or "I eat you" trees like in Poltergeist. No, just nice, leafy New England trees that you want to climb in or laze underneath. Nothing reeks of fail more than the moments in this film when director M. Night Shyamalan builds up the tension, shows you a zillion suicides, and then zooms into the monster - which looks like a bucolic scene from a Hallmark card!
Other monster failures can be traced to a lack of imagination, which certainly plagued the zombie/disease things in I Am Legend, as well as unmemorable beasties from the flick Boogieman and Stephen King's worst scare fail novel, Cujo. I should caution that a cheaply-constructed monster does not always equal scare fail. The partially-glimpsed yuck monster in The Descent may have been a fairly ordinary Gollum-like creature, but it scared the crap out of audiences because of the scary things it did. Meanwhile the giant monster robots in Terminator 3 were awesomely (and expensively) done, but completely unscary. In fact, the instant I saw those harvester Terminators I had to restrain myself from yelling SCARE FAIL! right there in the theater.
Of course no discussion of monster fail would be complete without mentioning the completely disappointing dragons in Reign of Fire (is Christian Bale a glutton for monster fail or what?), as well as the utterly pathetic Godzilla from Roland Emmerich's Godzilla. The best part of Emmerich's Godzilla is that he's totally creamed by the REAL Gojira in recent Japanese flick Godzilla: Final Wars. That G vs. G fight was totally meta, and totally rectified the fail.
Failure to Build Tension
Exhibit A for the failure to build tension is the haunted spaceship fick Pandorum. The characters are walking, walking, walking down those long, dark corridors, and then the monster LEAPS out. Yes, it probably made you jump because you'd almost fallen asleep during the build-up. Pretty much any movie that relies entirely on jumps and shocks is basically admitting to suffering from scare fail. Several entries in the Friday the 13th franchise, most notably the much-hyped Jason X, suffered from this problem.
Movies like The Shining, Paranormal Activity, and 28 Days Later make excellent use of tension, showing you bits of terror in between moments of nerve-wracking waiting for something to happen. Tension fail is sort of like blowing your wad too soon, or maybe too late. Think of how disappointed you were when the big reveal about the once-scary Borg from Star Trek was that they were controlled by a greasy torso with an English accent. Or when you realized the entire Saw franchise was about a guy in a stupid mask. Just as fear and intrigue reach their peak there's a giant "blah" instead of a scream.
Failure to Make Me Care About Characters Dying
When the headless horseman stabbed little kids to death in Legend of Sleepy Hollow, I really did not care. It's not that I don't think kids are nice little creatures; it's that I didn't care about these particular kids at all. Kill 'em for all I care. How about spooky Halle Berry in Gothika? Do you really care if she's having sex with the devil or crazy or trapped in an alternate reality? No, you don't. You just want her to shut up.
Even though 2012 isn't out yet, I'm already filled with torpor by the trailer. While I care abstractly about the destruction of my home state of California, I don't give a crap about whether the main characters are able to outrun that earthquake. Of course the worst is when you actually dislike the characters so much that you want them to die. Like the annoying, whiny medical students in Flatliners. Go ahead and have your damn near-death experiences UNTIL YOU DIE, people. And the snotty teens in I Know What You Did Last Summer? I actually think they deserve to die.
I should add that some soon-to-be-dead characters are intended to be loathsome, like the hipsters in House of 1,000 Corpses (including a snacky Rainn Wilson). You're supposed to be amused by watching these kids die, so that's not a fail.
But when fear turns to a kind of bored, satisfied schadenfreude, that is major scare fail.
Failure to Engage in Diverting Quippery
How many movies have you seen where the intrepid heroes are trying to have amusing banter, with each other or the monsters, and you begin to clutch your head in pain? This happens a lot in the movie version of Doom, as well as all the Blade movies. (In Blade, one character actually says to the vamps, "Go ahead... Bite me.")
Or how about this amazing quip-off from the tragically unscary Van Helsing:
Anna Valerious: We Transylvanians always look on the brighter side of death.
Van Helsing: There's a brighter side of death?
Anna Valerious: Of course. It's just harder to see.
And another fail moment in quippery, from Hannibal Rising:
Petras Kolnas: What did I ever do to you?
Hannibal Lecter: Aside from eating my sister? Nothing.
Cannibalism jokes! In a movie about a cannibal serial killer! Fail. You want good horror quippery? Just watch Buffy the Vampire Slayer, or one of the scarier episodes of Doctor Who.
Failure to Create A Scenario That Scares A Broad Range of People
Like monster failures, the failure to create a broadly scary scenario is probably at the root of most scare fail. For example, there is an entire subgenre of scary stories, like the Left Behind franchise, which is only scary for religious Christians. Stick an atheist Jew like me in the theater, or your typical J-horror fanatic from Tokyo, and you get a whole lot of fail. Same goes for movies like Reefer Madness or even a 1970s drug scare flick like Altered States. If you don't think drugs are a Scary Bad Thing, these movies will fail to fill you with The Fear.
But then there are other scenarios that fail because they are too murky to really bring on the shivers. The Mothman Prophesies is like this, with its nebulous alien/moth guy visions. Vagueness is almost never terrifying. Then there are haunted house flicks like 13 Ghosts and Amityville Horror. Some people are scared of old houses, but most of us feel pretty ho-hum about them. Is Satan in the basement? Really? Well, why don't you just call the Ghostbusters or Buffy or something? There are, of course, ways to do hauntings brilliantly - witness the haunted housing project in Candyman, which couldn't be more mind-blankingly scary.
The scary scenario fail also tends to creep up on formerly scary movies over time. Movies that are over 20 years old start to look campy rather than scary - witness the once-terrifying monster movies of the 1930s, or pretty much any slasher made in the 1980s. Still, there are some scary movies that stand the test of time, like Invasion of the Body Snatchers (the 50s version), The Shining, or (maybe) The Exorcist. I'll leave unanswered the question of whether we should deem a movie guilty of scare fail simply because it hasn't stood the test of time, or whether we should evaluate it within its historical context.
One scenario that clearly fails the fear test is the "real life alien abduction" story, which is returning to haunt us next week with The Fourth Kind. Unlike Close Encounters, an emphatically fictional flick which made abduction seriously terrifying, Fourth Kind is in the same subgenre as Communion (Whitley Strieber's autobiographical tale of being anally raped by aliens when he was a kid). It's supposed to be scary BECAUSE IT'S REAL. But what if you don't think aliens are real? Fail.
Fear can be highly personal, dependent for its effectiveness on your beliefs or experiences. But in order to avoid scare fail, it must transcend highly specific shocks and rain terror upon the masses.