V 2.0 

A standalone NeoForge mod that folds an endless liminal dimension into Minecraft — rooms that go on forever, something that hunts you in the dark, and a very long way down. Then it gives you a way to fight back.

No other mods required. Built almost entirely from vanilla assets, so it stays light and looks right alongside your shaders and resource packs.

Getting in

Nothing's wrong with your world yet. You have to make the first crack yourself.

Build a threshold. An iron rectangle, any size. The only rule is that the border must be unbroken iron, corners included.

Then put power into it. A full-strength redstone signal, on any part of the frame. A redstone block against it will do or lever.

Step in. You're across immediately.

The crack spreads

From the moment that first threshold opens, the world stops being safe.

Thin spots begin surfacing across the overworld — patches of ground that look exactly like the floor around them but hold no weight. Walk over one and you're simply gone.

The threshold runs both ways and raises a twin on the far side, so the way home is always behind you — if you can find it again, and if it came through whole. The Complex doesn't always let you leave the way you came. Sometimes the threshold arrives wrong, or blown apart, and the way out becomes one you'll have to build for yourself.

And a threshold is a switch. Cut the power and it closes. Restore it and it opens again. That matters more than it sounds like — see below.

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The descent

The Complex is sixty-four floors stacked into the dark, sorted into themed stretches that shift from world to world.

Backrooms — the ones everybody remembers. Yellow walls, damp carpet, the endless buzz of the lights.

Poolrooms — pale quartz tile and still, shallow water that never seems to end.

Grasslands — wide green fields and real trees under a flat blue "sky" that isn't one.

Now and then a shaft opens and drops you a floor. Once in a long while the ground gives out entirely and a pit swallows ten floors at once. The deeper you sink the darker it gets — except the grass, which stays bright and only grows lonelier.

And there is no bottom. Fall through the lowest floor and you come back in at the top, seamlessly. Cut your way up through the highest ceiling and you come back in at the bottom. The descent doesn't end. It just continues.

The rooms don't always keep still, either. Leave a corridor and come back to it and it may have quietly rearranged itself — a way through that's now a wall, a wall that's now a way through. Rarely. Just often enough to make you doubt your own map.

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What's down there with you

The Lifeform. One hunter, and it is patient. It keeps its distance, watching, until something in it decides — and then it runs you down. Hold your gaze on it too long and it tears open into black and is gone, only to be standing somewhere you aren't.

Still Lifes. The dimension's failed attempts to copy the people who've passed through. They wear faces you might know. Hit one and it gives up the act — it goes still, and drops a bowl of mushroom stew. Keep at it and the copy comes apart a piece at a time, a bowl for every limb, withering until there's nothing left.

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Misremembered places

Buried in the rooms are ruined miniatures of somewhere you've been: village houses, igloos, shipwrecks, ruined portals, end-city towers, bastion halls, woodland mansions, ancient-city ruins, fossils. Built from their real materials, then hollowed through and twisted wrong.

The Complex copied them from a memory, and it got the stone wrong.

Where there should be ordinary rock, there's something else.

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Memarium

A mirror-bright alloy that exists nowhere in your world. Not in your caves, not in the Nether, nowhere you can dig. Only here, misremembered in the structures. Standing in for the stone in every structure the Complex misremembered. It never saw real ore, so it made its own.

You can't mine the backrooms at first. The Complex is unbreakable. Your first Memarium, and the torn Remembered Upgrade schematic that makes it useful, come out of the chests in those ruined structures — the same shape as finding ancient debris before you can work it.

Then take it to a smithing table. Remembered Upgrade + a diamond tool + a Memarium ingot, and you have something that can finally cut this place open.

It is a key, not an upgrade

Two rules keep it that way, and both are deliberate:

• The Complex gives nothing back. Memarium tools break its blocks — and drop nothing at all. You can carve a doorway, a shortcut, a way down. You cannot mine the place.
• The alloy is wrong for other worlds. Outside the Complex it cuts at a fraction of its speed and wears out several times faster. It will not replace your netherite.

You go down there for what the place is. Not for the gear.

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Taking the world back

Thin spots are the overworld forgetting itself. Reality wears through where nothing holds the memory of what was there.

So you don't patch them. You remind the ground what it is.

The Memory Anchor

Salvaged survey hardware, rebuilt from what the Complex left behind: four blocks of Memarium, four of redstone, and an echo shard from an ancient city.

It is a full-strength redstone source in its own right — which is exactly what a threshold needs.

Wire an anchor to a threshold and the breach comes under control. The aperture flares white-hot as the link takes hold, and from that moment:

• No new thin spots form. Anywhere.
• Every thin spot already out there reverts — not to a hole in the ground, but to the block it ate. Ground you've never visited repairs itself the moment it loads.
• The threshold stays open, held, breathing quietly.

Break the wire and it all stops.

⸻

Your builds follow you down

Everything you've raised in the overworld is waiting in The Complex at the same coordinates — sunken into the floor, decayed, misremembered. The deeper its echo sits, the less of it survived.

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Losing your grip

A sanity meter drains the longer you stay in the Complex — the lower it gets, the worse the effects: screen veins, your heartbeat, sounds from nowhere. It only refills by leaving through a threshold or stepping from one room into the next; sit still too long in one spot, and it just keeps falling. A findable potion helps you cope in the meantime, Sanity, for a quick steadying effect.

Config

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⚠️ Updating from 1.3.0 or earlier

thresholds no longer use an iron door. Any portal built on an older version will not relight — tear it down and build a new frame. Worlds, inventories and everything else carry over fine.

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Join the Discord — report bugs, sort out mod conflicts, and see what's

coming next: https://discord.gg/6QV5kEw5R

⸻

Requirements

Minecraft 1.21.1 · NeoForge 21.1.0+ · Java 21 · No dependencies · Singleplayer and servers, solo or with friends.

Mind the thin spots.

The Backrooms Update

Some floors aren't as solid as they look.

A standalone NeoForge mod that folds an endless liminal dimension into Minecraft — rooms that go on forever, something that hunts you in the dark, and a very long way down. No other mods required. Built entirely from vanilla blocks and textures, so it stays light and looks right alongside your shaders and resource packs. 

Getting In

Nothing's wrong with your world yet. You have to make the first crack yourself.

Build an iron frame: a four‑block iron column up each side, with a single iron block at the top‑middle and another at the bottom‑middle. Hang an iron door in the gap and give it power — a lever, a button, any redstone, touched anywhere on the door or the frame. The doorway lights a soft, humming yellow. Step through.

From the moment that first portal opens, the world stops being safe. Thin spots begin to surface across the overworld — patches of ground that look exactly like the floor around them but hold no weight. Walk over one and you're simply gone, dropped into The Complex. The portal runs both ways and raises a twin on the far side, so the way home is always behind you. If you can find it again.

The descent

The Complex is sixty‑four floors stacked into the dark, sorted into themed stretches that shift from world to world:

Backrooms — the ones everybody remembers. Yellow walls, damp carpet, the endless buzz of the lights.

Poolrooms — pale quartz tile and still, shallow water that never seems to end.

Grasslands — wide green fields and real trees under a flat blue "sky" that isn't one.

Now and then a shaft opens and drops you a floor lower. Once in a long while the ground gives out entirely and a pit swallows ten floors at once. The further you sink, the darker it gets — except the grass, which stays bright and only grows lonelier. And there is no bottom: fall through the lowest floor and you come back in at the top, seamlessly. The descent doesn't end. It just continues.

What's down there with you

The Lifeform. 

One hunter, and it is patient. It keeps its distance, watching, until something in it decides — and then it runs you down. Hold your gaze on it too long and it tears open into black and is gone, only to be standing somewhere you aren't.

Still Lifes. 

The dimension's failed attempts to copy the people who've passed through. They wear faces you might know. Hit one and it gives up the act — drops a bowl of mushroom stew, goes still, and stays that way forever.

Glitched landmarks

Buried in the rooms are ruined miniatures of places you've been: village houses, igloos, shipwrecks, ruined portals, end‑city towers, bastion halls, woodland mansions, ancient‑city ruins, fossils and more — built from their real materials, then hollowed through with holes, sculk and cracked stone. Familiar, and wrong.

Your builds follow you down

Everything you've raised in the overworld is waiting in The Complex at the same coordinates — sunken into the floor, decayed, misremembered. The deeper its echo sits, the less of it survived.

A few things worth knowing

Furnished rooms hide chests. Most hold food; a rare few hold the iron and the door to build your way back out from the inside. Fire won't spread or destroy here. The Complex itself can't be broken — only the blocks you place can. Ops & creative: /backrooms locatepoi, /backrooms tppoi, /backrooms thinspot. Requirements

Minecraft 1.21.1 · NeoForge 21.1.0+ · Java 21 · No dependencies · Works client and server.

Mind the thin spots.