What we cover
The first library covers checkpoint procedure, anomaly screening, medical tests, quarantine decisions, and the launch progression through Day 30. Overlapping document and clearance intent is merged into one checkpoint guide. Exact ending and achievement conditions remain deferred until current-build evidence is strong enough.
How evidence is graded
The current Steam listing, Alawar's official game page, and official Steam announcements establish the game's systems. Current-build walkthrough observations may establish tool unlocks and example daily rules, but randomized visitors and changing bulletins are labeled. A competitor's unsupported theory never becomes a fact here.
Independent status
This is an independent fan-made guide site. It is not affiliated with, endorsed by, or operated by Alawar, Valve, Steam, or another guide publisher. Names, screenshots, and marks belong to their respective owners and are used only to identify and discuss the game.
Corrections and updates
Security 51 launched on August 12, 2026, so patches and branching discoveries may change what players observe. Every guide shows a review date and source boundary. A useful correction includes the page, shift or branch, current build, and a reliable source or reproducible observation.