Blue Prince is a puzzle game that is filled with mysteries, twists, and turns. If you want to learn the whole story of what this indie title is about, you'll need to solve a whole bunch of puzzles and read every memo, book, note, and card you come across.

One of the many secrets that holds more information is the Underpass in Blue Prince; inside the tunnel leading to the final lever, there is a Red Door that cannot be unlocked from the underground. Instead, you'll need to have a different room inside the house to crack it open.

Blue Prince Achievement Trophy Guide All Trophies
Complete Blue Prince Achievement Guide

To get every achievement and earn every Blue Prince Trophy, players must complete some of the toughest challenges in the game.

How to Get to the Red Door

In order to get to the Red Door, you will need to have unlocked the Basement with the Basement Key from the Antechamber in Blue Prince. After that, you will need to find the three Basement doors, unlock them, and figure out the cog puzzle. Once you learn how to walk across the giant cog by turning the cog so it faces one of the three tunnels you have access to, you can walk across it to the blue tunnel on the opposite side of the room.

Blue Prince Safe Codes All Safes Locations Red Room 1

Next, before you open the gate that is along the blue tunnel in the Underpass near the Basement in Blue Prince, you will need to look for an opening on your left. This will be really hard to see; it blends in really well with the surroundings. Other than a pretty and useless overlook of the forest around the manor, there is only one thing to see in this location: the Red Door itself.

Open the Red Door in Blue Prince

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Now that you have found it, you need to go back into the house and keep drafting floorplans until you find the Boiler Room in Blue Prince. Then, you need to rotate the three-pronged steam pipe until the red box on the wall is lit up, showing it is active. This will unlock the Red Door in the Underpass. Keep in mind that you have to walk all the way back to the Underpass, so you will want to make sure you have plenty of steps to get there.

After that, you will just need to walk up to the Red Door for it to open. Now you can continue your exploration of the underground tunnels and puzzles hidden deep underneath your new manor, including a new puzzle box, more lore, and even another Blue Prince safe with a red envelope inside.

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Blue Prince
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Released
April 10, 2025
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WHERE TO PLAY

SUBSCRIPTION
DIGITAL
Checkbox: control the expandable behavior of the extra info

ESRB
Everyone 10+ / Alcohol Reference, Simulated Gambling
Developer(s)
Dogubomb
Publisher(s)
Raw Fury
Engine
Unity
Number of Players
Single-player
Steam Deck Compatibility
Playable
PC Release Date
April 10, 2025
Xbox Series X|S Release Date
April 10, 2025
PS5 Release Date
April 10, 2025
Genre(s)
Puzzle, Adventure, Exploration, Strategy
OpenCritic Rating
Mighty
X|S Optimized
Yes
PS Plus Availability
Extra & Premium
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