I have written two novels and a novella that fall in the horror genre. All three are scary, and are calculated to cause bad dreams and nightmares. Otherwise, what's the point?
My favorite horror story horror story is the movie Psycho, which is actually one of the least scary horror stories I have observed.
Well it's not that it's not scary, but the movie lacks the high-end special effects movies are fortunate to have today as well as good actors. You have to admit the screams are a bit too cliche but that's why it's considered a "classic" movie. The actual story is still creepy as hell (mind my french).
Meaning the movie does not have good actors? Even Anthony Perkins? (Also, that scene kind of illustrates what I said earlier -- it is not exactly a "scary" scene, but the horrible subtext that simultaneously repulses the viewer and compels the viewer to keep watching out of morbid curiosity is what makes this a good horror movie.)
It has to be scary. Horror fiction, horror literature and also horror fantasy are genres of literature, which are intended to, or have the capacity to frighten, scare, or startle their readers by inducing feelings of horror and terror.
Eh, I'm not really a movie critic so I don't really have a right to say what makes actors good or bad :S
The classic Psycho is a good movie, although it never frighten me. What gave me the creeps was original The Shining movie.
I've thought about this a lot. I'm a huge horror aficionado, and the first stories I'm writing are based purely in horror. And while I am trying to make them very scary, I have to say this: horror itself does not have to be scary! I found this while consuming tons and tons of horror movies, and after watching a whole lot of them, I realised the ones trying to be "scary" weren't exactly horrific, whilst the ones that were horrific weren't always scary. I'll throw some examples out. I'd say some of the most horrific parts of the original Exorcist were the vomit projectiles, crucifix masturbation, and head spinning. And while they could make you squint, today many people would find it simply too bizarre to run out of the room. However, what's always had the staying power of fear in the movie are actually the suspenseful parts. Remember how the mother Chris MacNeill goes out for a short period to have a conversation with the maid, and all of a sudden you hear Regan screaming for help? My heart always drops in fear for that scene, but that's an element of suspense (a technique of thrillers) right up until you see the horror of the violently shaking bed (which again, becomes too bizarre for people nowadays that they've made parodies on the internet about it). Again, another scary scene? The Spanish horror movie [REC]'s scariest scene is the final five minutes in which you see almost nothing except for the final moments. That entire brilliant sequence isn't based on the overtly horrific elements like the rest of the movie, but is instead based on suspense of not knowing what lies beyond, which is again a fundamental aspect of the thriller genre, not the horror genre. A very similar scene is of course the final scene in The Silence of the Lambs, which is classified as crime fiction i.e thriller. TL;DR, horror doesn't have to be scary, but it generally is when coupled with thriller. The best stories are usually a combination of horror-thriller, which masters like H.P Lovecraft, Edgar Allan Poe, and Alfred Hitchcock used effectively.
