What makes a horror map atmospherically scarier?

We’ve all probably played a custom horror map at some point. Many of them, however, consist of little atmosphere or buildup and rely only on cheap jump scares (like “screamers”) and ridiculous amounts of blood and gore.
A map that keeps the player on his toes all the time, however, one with much atmosphere and few (if any) jump scares, is far scarier. A map that, for instance, uses the unknown, or outright bizarre and surreal, to disturb the player without using a bogeyman that jumps from around a corner, without even a single drop of blood.

So now I ask you: what makes a horror map truly scary?

Atmosphere definitely plays a big part in a map. I love to keep a depressing atmosphere that leaves the player feeling all alone and that there’s no hope. Keeping areas dimly lit can cause the brain to play tricks on you. Making you think that there’s something there, when there really isn’t.

sound design.

Dim lighting, keep the player guessing about what’s going to happen, fog, ambient noise.
Make them feel like they need to keep watching their back.

Long shadows, noises of things moving, or scraping. Loud noises caused by normal things happening (door locking behind a player, a bottle falling to the floor etc).

Lots of blood is not scary…after a while, the player just gets used to it. There is however a certain frequency that can be used to generate unease within a human. It’s something built into us for millions of years, part of the fight or flight mechinism. The dev team for Thief 4 used these frequencies for the asylum level.

Keep them on their toes, but not with cheap scares. Sounds are the key.
The wind (Storms are overused) howling outdoors and entering the building, perhaps slamming unseen doors open/shut. Scraping, rustling, subtle creaking. Cans rolling from around a corner…Dead Space is a good example. You want the feeling that you may not be as alone as you’d like to think.

Lighting: Don’t make it pitch black, instead have it dim and include some slightly flickering light sources, although don’t have an entire room flickering, that’s just annoying.

Another important thing is that although headcrab zombies can make you jump if they were to suddenly come out of nowhere when you’re in suspense, they are a bit of a cliché. It is very possible to create a scary and unsettling environment without monsters, blood or supernatural entities.

Possibly remedy might be to have a headcrab amble past, making a bit of noise, but ignoring the player. It gives the person a jump and a frantic grab for a weapon, only to find that its harmless.

I’d prefer a consistently frantic mood. Always taking care to look behind your back for a threat that could come at any time. A quiet ambience and a somber soundtrack would play a key role here imo as well as aesthetics. Then there’s when you’d be chased. Cramped spaces, some trifle debris on the floor, dim lighting together with rapid background music would all contribute to a sense of claustrophobia and heightened tension.

On the matter of the map’s environment, I notice most maps make heavy use of fog and dark skyboxes/lighting and a uncanny soundscape which doesn’t always have to be the case. If you can do so effectively, you could have a setting in a seemingly safe environment only to later reveal how dangerous it really is. The only examples I can pull out of my mind right now are from creepypastas.

Music isn’t always integral; You should only use it moderately, at places where it is most appropriate. Too much music can be fatiguing to the ear imo.

If you need some inspiration, the most obvious source would be to read some horror fiction and watch horror films/videos. There’s this thread in GD with a ton of really fucking creepy shit including videos, pictures and even solely audio. Also, you can try visiting the Creepypasta Wiki. It’s loaded with a lot of scary stories though most of them aren’t exactly good.

Distant footsteps.

A proper ambience and lighting, not something like broken lights that blink with env_sparks.

Make sure it ends like this:

Play a game of Metro 2033 while being on the surface. That shit is fucking scary. Only thing which tops that would be Amnesia, but that’s simply the constant fear of getting killed.

This, a major part of human emotion is derived from sound.

A friend asks: which is more unsettling: warm lighting or cold lighting?

The thing that scares me the most when playing horror games is definitely sound, or a sort’ve ‘impending doom’ build up. An example of the latter is the tenseness of getting chased in the game Ao Oni, both you and the monster are a bit slow, but I was still breathing heavy and mashing my keyboard to get away.

Definitely cold. Warm seems too friendly. Cold seems dreary, depressing, the actual feeling of the frigid coldness comes from the color. Nobody likes to be cold, remember

Coldness gives a feel of horror while warmth/hotness gives a dramatic atmosphere.

You really need to take advantage of the players curiosity and sanity.

Blood is one of the best ways to creep people out. But only if used sparingly. If you’re in a creepy abandoned house and whilst exploring you come across a trail of blood that leads to an up-turned table. Then you’re going to be curious to see what is behind it. This creates suspense and fills the player with fear. Is anything there? Is it going to jump out at me?

Now if you added a lot of blood in prior rooms then the player is highly likely to just avoid this blood trail because their mind is already desensitized to it.

Another good way is sound. There’s nothing that scares me more than confidently walking up to a doorway only to get about a foot away and hearing a monster groan on the other side. It doesn’t exactly make the player jump, but it makes them think fast. They’ve got to escape or hide, and they’ve got milliseconds to do so!

Really weird monsters tends to creep people out.

Something like that:

The problem with blood in video games is that you barely ever put any thought into, even unconsciously. I don’t at least. It’s just too common an element in video games. You would have to have some clever way of attracting the players attention to it without making it obvious what you’re trying to do.