Image: u/aCakeShip on Reddit · A room in Dimension 9’s Backrooms
Dimension 9: an infinite Backrooms that Opus keeps building
The maker set Opus 5.5 a standing directive to keep adding rooms, characters and entities to a multiplayer browser Backrooms with proximity chat, so even the maker doesn't know what's in it.
Credits
Earliest dated source:
The full story
Dimension 9 is a free multiplayer Backrooms game in the browser that keeps building itself. The maker hand-built 15 seed rooms and wrote the world's rules: what makes a room feel liminal, the lore rooms must tie back to, and a taste profile that learns from their notes.
A serverless app on fal runs Opus 5.5 in a loop. It reads those rules and where players go and linger, then builds the next room: layout, light and sound, its residents, the things that hunt you and the writing on the walls. fal's image and 3D models make concept art and props, and Opus writes and tests the code. The maker reviews each batch, walking the rooms and leaving notes such as "stranger" or "keep this one".
It had about 70 rooms when posted. It is built with three.js, with multiplayer and proximity chat on Cloudflare Durable Objects.
How it was done
Tools
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Sources
From a short post by the maker, so the details are as they tell them.
- Reddit: I built an infinite, self-evolving Backrooms with Opus 5.5. Even I don’t know what’s in it anymoreReddit poster: aCakeShipPosted
The maker's post in r/ClaudeAI on how Opus builds new rooms.
- The project: dimension9.space
The game itself, playable in the browser.