66%Strong matchInside the Backrooms
82%38k82% positive reviews, Very Positive across 38k reviews·Horror · Multiplayer
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Unknown Rules is an independently created multiplayer online horror game that supports 1-4 players.
Unknown Rules is an independently developed first-person horror puzzle game.
Every region has its "chosen unlucky ones"—ordinary people who, through sheer coincidence, fall into the Backroom. Before their descent, however, they were simply diligent workers in their respective Frontrooms. You can choose to work alone or team up with friends to complete your tasks. Perhaps, during your routine, an unexpected journey awaits.
***************************************************************************** Note: Only one Frontroom level can be selected. All Frontroom levels lead to Backroom Level 0.
Level 1: Office You are an ordinary office worker. On this day, the office is eerily empty. After working overtime, you decide to rest your head on the desk for a nap. When you awaken, the environment has shifted into something unrecognizable.

Level 2: Logistics Warehouse You are a night-shift warehouse packer. As usual, you retrieve, package, and ship orders. But upon completing your quota, you discover an unsettling note.
Congratulations—you’ve been chosen. Due to the scale of certain levels, please review the level descriptions before proceeding.
***************************************************************************** Currently Developed Backroom Levels (Descriptive reference order only; not actual gameplay sequence) Note: Backroom levels are unlocked progressively and cannot be freely selected.
Procedurally generated terrain using PCG technology. Requires real-time lighting (RTX 2060 or higher recommended). A fixed-map version for lower-end GPUs will be added later.

A serene "poolcore" environment optimized for multiplayer fun. Currently uses Lumen soft ray tracing.

A windswept, sinister suburban nightmare.


Technical note: Current scanning relies on ray tracing (RTX 2060+ required). A low-end GPU alternative will use basic particle scanning (less precise, ignores moving objects, no object data—scenery only).

To survive, manage and use every item you find. Your inventory includes 8 backpack slots and 2 pocket slots.
Boredom is inevitable, so I’m developing open-ended features to keep players engaged. Two experimental party maps are now available:
For Go enthusiasts: Challenge a friend to a match while listening to music. Note: This mode is unpolished due to limited development time, but it supports full Go matches.

Input a video URL (.MP4, .m3u8, or untested rtmp/rtsp streams) to watch together. Basic playback is functional, though features are incomplete. Contact the developer for issues.

Steam data © 2026 Valve Corporation. Trademarks are property of their respective owners.
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The best games like Unknown Rules are Inside the Backrooms, Backrooms Society, Backrooms: Escape Together, Backrooms Rec., and Backroom Company.
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