SELF-CONTAINED DEV BLOG: DESIGNING FEAR IN TIGHT SPACES

First person horror games live or die on the width of a hallway. I mean that literally. I have a spreadsheet.

I've been working on Self-Contained for long enough now that I have actual opinions about this stuff, the kind of opinions that sound insane when you say them out loud to a non-gamedev friend at dinner. "Yeah the hallway is ninety four centimeters wide because ninety six felt too generous." They nod politely. They do not understand. But you, reader, you are a horror nerd who clicked on a dev blog titled "designing fear in tight spaces," so you understand. You get it. You are my people.

So let's talk about tight spaces. Specifically, let's talk about designing first person horror inside the physical constraints of a container ship, which is what I've been doing for the last however many months on Self-Contained. I've written before about why I picked a container ship as the setting and the structural reasons it works for solo development. This post is the follow up. This is the part where I actually get into the level design.

The hallway is the monster

Hot take. The hallway is the monster. Not the thing in the hallway. The hallway itself.

When I started roughing out the accommodation block for Self-Contained, I spent something like three weeks just tuning corridor widths before I built anything else. That sounds like a ridiculous use of time and honestly maybe it was, but I had a theory I wanted to test. The theory is that the single most important variable in first person horror is the distance between the player's shoulders and the nearest wall. Not the lighting. Not the textures. Not the audio. The width of the space.

Real container ship accommodation corridors are about ninety centimeters to a meter wide. That is tight. That is, for comparison, about the width of a standard interior doorway in a house. You can pass someone in it but only just. You cannot run past them. If they stop and stand still, you stop too. Your body language changes. Your breathing changes. This is a real measurable thing that happens in your actual nervous system when a space narrows around you.

In a video game you can cheat these numbers. Most horror games do. You'll find that their "tight" corridors are actually a meter and a half to two meters wide, because anything tighter starts causing camera clipping problems and makes the player feel physically nauseous after a few minutes. There's a reason for the cheat. But I think the cheat also dilutes the fear. You've never actually been in a real one-meter-wide corridor with no windows and a metal ceiling. When you put the player in that space for the first time, their body reacts before their brain does. That pre-cognitive flinch is what horror is trying to trigger.

So I'm tuning closer to reality than most games do. Ninety four centimeters. Not ninety six. I have opinions.

Blocked sightlines as a grammar

The second thing a tight space gives you, which is related but different, is the ability to completely control what the player can see at any given moment.

In an open environment, the player always has multiple escape vectors in their visual field. They can see three doors, four windows, a distant treeline, a staircase. Their brain is constantly doing threat assessment across all of these vectors simultaneously. That's actually relaxing, in a weird way, because it distributes the attention. No single threat can dominate because there are too many potential threats.

In a ship corridor, the player can see exactly two things. What's ahead of them, to the limit of the flashlight beam. And what's behind them, if they turn around. That's it. There are no windows. There are no branching paths most of the time. There are just two directions, and one of them is where you came from.

This is enormous design power. Because now I can control, frame by frame, what your attention is doing. I know exactly where you're looking. I know exactly where you're not looking. I can put something behind you and I can put something ahead of you and I can rotate your fear back and forth between those two points like a metronome. The blocked sightline isn't a limitation. It's a grammar. It's the thing that lets me write sentences with your attention.

A doorway at the end of a corridor is a question mark. A bend in the passage is a semicolon. A T-junction where you can go left or right is a fork in the sentence where I get to decide which clause you experience first. This is the stuff you can't do in an open world. You can only do it when the space itself has been narrowed down to something the designer can point at.

The ship's geometry is already horror architecture

Here's something I didn't fully appreciate until I'd been building ship interiors for a few months. The geometry of a real container ship is, by its own engineering logic, almost perfectly horror architecture. I did not have to design a scary building. I just had to faithfully model the existing one.

Watertight bulkheads divide the ship into sealed compartments. Every few meters you pass through a heavy metal door with a spinning wheel handle. Those doors are not decorative. They are there because if the hull breaches, you want to contain flooding to a single compartment and save the ship. What this means for the game is that the player is constantly passing through these pressure-rated doors, which all look the same, which are all heavy, which all have that specific clang when they close behind you. Each doorway is a commitment. You are sealing yourself into the next room. The geometry is doing the tension work for free.

The ladders are another one. Container ships have vertical ladders everywhere. Not staircases. Actual straight metal ladders that you climb with both hands. To go from one deck to another you have to physically commit to a vulnerable animation, facing the wall, back to the room, using your hands on the rungs. I didn't invent that. That's just how the ship works. And it's perfect for horror because the player cannot defend themselves during a climb. They cannot turn around. They cannot run. They are climbing, and the space above and below them is a mystery, and something can be in either place.

The engine room has catwalks. Narrow steel grates suspended over two story drops, with machinery the size of a bus churning and rumbling below. You don't have to invent vertigo. It's already there. You're just going to work.

I think the most honest description of what I'm doing on Self-Contained is that I'm not designing a horror level, I'm modeling a real space accurately and letting the space do its own work. Every time I've tried to "improve" the geometry for game feel, the result has been less scary, not more. The ship knows what it's doing. I'm just the scribe.

Metal is an acoustic monster

Now let's talk about sound, because sound in a ship is completely different from sound in any other horror setting I've worked with.

A container ship is made of steel. Thousands of tons of it, welded into a hollow box. That box sits in water. The water transmits vibration from the engines, from the waves, from the propeller, from every other ship for miles around. The steel amplifies and resonates with that vibration like the body of a guitar. The inside of a ship is never quiet. It is a symphony of low-frequency hum, creaking hull plates, the subsonic thud of waves against the bow, distant clangs from somewhere unspecified, the whine of ventilation fans that are somehow always just far enough away to be ambiguous.

From an audio design perspective this is a dream and a nightmare. A dream because the ship is doing half of my job for me. The ambient soundscape is intrinsically uncanny. A nightmare because I have to design sound cues that cut through that soundscape, and that's genuinely hard. You can't do a normal horror sting. A normal horror sting gets swallowed by the baseline noise.

My solution has been to lean into the reverb characteristics of metal compartments. Every space in the ship has a real acoustic fingerprint. The engine room is a huge reverberant cathedral of bass. The corridors are tight hallways with hard reflections that create this flutter echo on any sharp sound. The accommodation block is slightly dampened because of carpet and upholstery but still metallic enough to feel wrong. I'm treating each compartment like its own instrument. I want you to be able to hear, by ear alone, what kind of room you're in even with your eyes closed.

The "distant clang" is my favorite trick. A single sharp metallic impact, processed through the reverb of wherever the player actually is, but panned and attenuated to suggest it came from somewhere else. Somewhere you can't see. Somewhere on the ship. The player hears it and immediately asks the worst question a horror player can ask, which is "where." Not "what." Just "where." And because the ship is enormous and they've only been in a tiny fraction of it, the answer is always "somewhere you haven't been yet." I wrote more about how I'm thinking about this in my post on sound design in horror games if you want to go deeper on the theory.

Sound in a metal space is a horror weapon. It is possibly the most powerful weapon a container ship horror game has. I am not planning to waste it.

The flashlight is a relationship

Okay, last big topic. The flashlight.

Every first person horror game has a flashlight, or something equivalent. Amnesia has the tinderbox and the lantern. Outlast has the camcorder. Alien Isolation has the motion tracker which is sort of a flashlight of a different kind. Self-Contained has a maintenance flashlight because you're on a working ship and a working ship has maintenance flashlights in every locker.

The thing I've come to believe about the flashlight, after probably too much thought, is that the flashlight is not a tool. The flashlight is a relationship. Specifically, it's the player's relationship with their own fear.

When you hold a flashlight in a dark tight space, you are making a choice, every second, about what to look at. You are choosing what to illuminate and what to leave in darkness. That choice is a confession. It tells me, the designer, and also tells you, the player, what you are afraid of. If you keep sweeping the beam behind you, you are afraid of something following you. If you keep the beam fixed forward, you are afraid of what's ahead and you've written off the behind. If you point it at the floor, you are trying to minimize what you see because seeing is too expensive.

I want to design around this. I want the flashlight beam to be small enough that you can't cheat it. You cannot flood a corridor with light. You have to pick. A lot of horror games give you a beam that's effectively a cone the width of the whole hallway, which defeats the whole point. My beam is narrower than the corridor. You can light the floor or the ceiling or the left wall or the right wall but you cannot light all of them at once. You have to triage your attention. The act of using the tool is an act of committing to a theory about where the threat is.

And of course sometimes the theory is wrong. Sometimes you're pointing the beam forward and the bad thing is behind you. That's the cost of the bet. I want the player to feel that cost. I want them to feel that they, personally, chose where to shine the light and they, personally, were wrong. That's a much more intimate horror than a scripted jumpscare. You jumpscared yourself, in a sense, because you bet on the wrong direction.

I also want to resist the urge to make the flashlight run out of batteries as a pacing mechanic. It's a cliche and I think it actually undercuts the flashlight-as-relationship idea. If the flashlight is going to die no matter what, then your choices about where to point it don't matter, because all paths lead to darkness. The more interesting horror is when the flashlight always works, but your choice about where to point it is permanent. The unlit area stays unlit. Something may have been there. You'll never know.

The constraint is the engine

If there's a throughline across all of this, it's that the constraints of the setting are not limitations I'm working around. They are the actual creative engine of the game. The tight corridor is the reason the horror works. The blocked sightline is the reason the pacing works. The metal reverb is the reason the audio works. The narrow flashlight beam is the reason the player's fear becomes their own.

I could make a bigger game. I could make an open environment with multiple routes and vistas and panoramic horror moments. But I'd be fighting my own premise. Isolation horror lives on compression. It lives on the player being unable to escape not just the threat but the geometry itself. The ship is a coffin shaped like a workplace. That's the pitch. Everything I design has to serve that pitch or it doesn't belong in the game.

If you're a dev working on your own first person horror project, I'd say the question worth asking yourself isn't "how do I make my space scarier." It's "what can my space already do that I'm not taking advantage of." The answer is usually something the architecture is already whispering at you. You just have to shut up and listen. If you want more on the general principles, I wrote a bigger post on what actually makes a horror game scary that goes broader than just the architecture stuff.

Alright. Back to the spreadsheet. I have a stairwell to tune.