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. 

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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.

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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.

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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.