In Blue Prince there are a lot of locked doors, rooms, and puzzles. One of them is the Precipice underground room that can only be accessed after you find all 4 Gas Valves in the game.
However, finding all four gas valves isn’t as easy. The problem is that some of the valves are actually locked behind doors or puzzles.
The Precipice lacks direct upgrades but contains several early discoverable secrets which will help you understand the game’s mechanics better.
A secret entrance to the Underground exists from the Precipice area. Using the Burning Glass which you can create in the Workshop by combining the Metal Detector and Magnifying Glass to light all candles in the circular room near the underground Reservoir will grant you a permanent shortcut between the Precipice and Reservoir and Room 46.
Gas Valve #1
The Apple Orchard contains a permanent upgrade room which is located behind a locked gate near the camp. The code [11-28] serves as the key to access this area. The lever rests against the left wall of the space after entering.
Gas Valve #2
The Gemstone Cavern functions as a permanent upgrade room and contains another lever. The V.A.C. puzzle located in the Utility Closet requires the Breaker Box to unlock this room which leads to the Gemstone Cavern. The colors on the box need to be in the following order: off, blue, green, white, red, purple.
Gas Valve #3 and #4
The West Gate on the Grounds leads to random rooms which include the Hovel and Schoolhouse. The Garage gate needs power restoration through the Breaker Box located in the Utility Room. After drafting the Garage you should exit through the garage door. The lever in the Hovel is positioned against the back wall.
The Schoolhouse lever is positioned behind the water heater which is located in the center of the first room. The Outer Rooms appear only on the outside of the house so you will need to perform multiple random loops to find both rooms.
These four gas valves will light the four braziers to activate the elevator that leads to the Underground room. It is also a location where you find one of the Disks on an altar.
