Delirium

I wanted to make a horror shader where the scary stuff isn't painted on your screen. It's in the world.

Delirium is a BSL edit that simulates delirium — the state where you can no longer tell what you're seeing from what's actually there. It starts with almost nothing. A dirty film over everything. Something flicking past at the edge of your vision. Give it time, or turn it up, and the world starts filling with things.

All of BSL's lighting, shadows, water and sky are still underneath. Delirium sits on top.

The shader works out where every pixel actually is in the world, and because Minecraft is made of flat square faces, every wall, floor and ceiling gets its own grid. The spiders live on those grids. Walk past one, and it stays on the wall where it was.

The figures get real coordinates too, and they're hidden properly behind blocks. So it can stand in a doorway. It can lean out from behind a wall. You can turn around and walk away from it, and when you look back it's still standing exactly where it was.

That's the whole difference between a horror filter and the feeling that something is in the room with you.

What you'll see

Roughly in the order it arrives:

The film. A filthy amber cast, like an old water-stained photo, with rust-coloured stains creeping in at the edges.

Your eyes go wrong. Bright light blows out into a dirty glare, dark places turn murky instead of black, and you can't focus on anything close to you — near things are the blurriest, which feels deeply wrong once you notice it.

The edge of your vision. Tiny dark things flicking past, gone before you can look. Soft shapes drifting across your sight.

Spiders. They sit perfectly still, then scuttle. At first you'll only catch them from the corner of your eye. Later they're on every wall, and some of them are big.

Shadow people. Dark human shapes standing just out of view. Sometimes too small. Sometimes too tall.

Faces in the walls. They don't get pasted on — they rise out of the stone and plaster that's already there, with hollow eyes and open mouths, and then sink back in.

The Hat Man. Tall. Long coat. Wide brim. Nothing else. Early on he's gone the moment you look straight at him. Later he stops leaving. Later still his eyes come on. And sometimes, between glances, he's closer than he was.

At the top end, real mobs start going dark too, and it comes and goes — so you stop being sure which shapes around you are actually there.

It doesn't hold still

The intensity slider sets a baseline, but it wanders on its own around that. There are long quiet stretches where it almost lets you go, and then it comes back harder than you set it. It also gets worse at night, and worse again in caves.

So you never quite settle in. That's deliberate.

Settings

Everything's under Shader options → Delirium.

• Intensity — ships at 35, which is "something is wrong". 70+ is where it gets properly bad.
• Waves — how much it fluctuates on its own. Set to 0 for a fixed level.
• Night & Darkness — how much worse it gets after dark.
• Jump Scares — on or off. They never happen below about 70 anyway.

Then three pages — Them, Your Eyes and Reality — where every single layer can be dialled down or switched off. Hate spiders? Turn them off and keep the rest. Only want the Hat Man? Go for it.

Warnings

This is a horror pack and it's meant to frighten you. It has spiders (lots, at high settings), shadow figures, faces, and jump scares at high intensity.

Photosensitivity: nothing strobes or flashes anywhere in the pack. Nothing repeats faster than three times a second, every fade to black takes at least half a second, and jump scares are single sudden appearances, never flickers. It does have sudden appearances and some screen shake — if that bothers you, switch off Jump Scares.

Requirements

• Iris or OptiFine
• Works in the Overworld, Nether and End
• Leave TAA on if you can

Every effect below its threshold is skipped entirely, so at low settings it costs very little. Spiders only exist within 16 blocks of you. If you need frames, drop Quality to Fast.

Good for

Halloween, obviously. But also horror maps, survival in caves at night if you want to suffer, scary recording sessions, and anyone who's ever felt like something was standing in the corner of a dark room.

Credits

Delirium by WetCardboardMC.

Built on BSL Shaders by Capt Tatsu — capttatsu.com. All of the underlying lighting, shadow, water and sky work is BSL's; Delirium adds its own layer on top. Please respect BSL's terms.

Not an official Minecraft product. Not approved by or associated with Mojang or Microsoft.