Callisto Protocol: The Commonality trophy - where are the Secret Rooms? The Callisto Protocol guide
This trophy guide page tells you how to unlock The Commonality achievement in the Callisto Protocol game. We explain where the 2 Secret Rooms associated with the trophy are - you'll find them in the Aftermath and Below stages.
Last update: 06 December 2022
On this page of the Callisto Protocol guide, you will find information on how to get The Commonality trophy - discovering the Mystery of Kallpolis. Our walkthrough shows where to find two Secret Rooms, which must be explored to unlock the achievement. We've covered fragments of the Aftermath (Secret Room 1) and the Below (Secret Room 2) stages.
Secret Room 1 - Aftermath chapter
To get The Commonality trophy, you need to find 2 Secret Rooms in a single playthrough. Each room will have, e.g. a collectible - audio log.
The first room can be found during the Aftermath stage, specifically during the objective to locate the Medical Facility.
After using the large B3 Maintenance passage, you will reach a fork. Don't choose Maintenance B414 passage, because it leads to the next locations. Instead, go straight ahead and use the knife to open the door of Workshop B415 (picture).
Supply B426 passage is in front of you, but it is closed. Enter the right ventilation shaft shown in the picture.
Crawl through the long shaft. You will find yourself in a corridor with blue lighting. Reach the narrow passage shown in the picture - it leads to secret room 1.
Go to the other end of the room. There is an audio log on the table.
You can return to the top by going to the ladder. You will unlock the previously passed Supply B426 door from the other side.
Secret Room 2 - Below chapter
The second room can be found in the level Below, specifically during the mission objective of locating the Power Reactor.
After defeating the crawling monsters, the main character will eventually reach the ladder shown in the picture above (you can see a large inactive fan behind it).
Right after using the ladder, do not turn towards the reactor, but squeeze between the rocks located in front of you (there is a white logo next to the passage).
Move through the corridors and be ready to defeat some monsters. You will come across a locked passage shown in the picture and, following the hint from the arrow, you have to go around it from the right side.
You will reach secret room 2 (picture) and the game should now unlock the Commonality trophy .
Approach the big table and you'll find a new secret - audio log.