Every safe code, radio frequency, and lockpick puzzle in Signalis is scrambled differently for your specific playthrough — so no guide can hand you a code that just works. What this guide gives you instead is the actual method behind every major puzzle (the Classroom Safe, the Sword and Tree wall safes, the Gas Valve, the X-Ray keycard, the Lockpick puzzle, and the Shrine Box), plus exact routes to the Revolver and every ending, so you’re never stuck wondering what a puzzle even wants from you.
Quick Answer Sheet
| Puzzle | Location | What You Actually Need |
|---|---|---|
| Classroom Safe | B1 — Class 4B | Fixed default code 204512, found on the “Mon & Tochter” manual note |
| Sword Wall Safe | B3 — Nurse Station | Tune radio to the “Sword” frequency from the Frequencies document (randomized per save) |
| Tree Wall Safe | B2 — Office | Tune radio to the “Tree” frequency (randomized per save) |
| Gas Valve Puzzle | B3 — Incinerator Room | Match CO2/GAS/O2 dials to the red line by watching the arrow indicators |
| X-Ray Room / Blank Key Card | B3 — Imaging Room | Read the card’s pattern under X-ray, then reprint it on the Card PC in the Office |
| Lockpick (Pin) Puzzle | Various locked doors | Align all 4 pins to the center junction line, one at a time |
| Shrine Box (Astrolabe) | B8 — ADLR Study | Match ring positions to the Star Map in the Briefing Room |
| Revolver | B6 Weapon Case + B7 Hunter’s Key | Combine both items in your inventory |
Signalis randomizes almost every safe code and radio frequency per save file. If a guide anywhere gives you a specific 5-digit number for the Sword or Tree safe, it won’t match your game — the method below is what actually transfers between playthroughs. The one fixed exception is the Classroom Safe’s default code, which is the same for everyone.
What Is the Signalis First Puzzle, and What’s the Code?
The very first puzzle you’ll hit is the Classroom Wall Safe, and it’s the one exception to the randomization rule. You’ll find a note called Service Request Form F-29 complaining that the safe keeps resetting to its factory default — and elsewhere in the same starting area, a note titled “Mon & Tochter High-Security Wall Safe” actually prints that default code.
Enter 204512 into the safe and pull the dial. Inside is the Classroom Key, which opens your path forward.
How Do You Solve the Signalis Safe Codes (Sword and Tree Wall Safes)?
Once you have the radio, two more wall safes show up, and both work the same way:
- Find the Frequencies document — the Nurse Station’s version is picked up in the Interrogation Room on B2, and it lists a radio frequency for each safe’s engraved symbol (sword, tree, etc.).
- Check the actual safe to see which symbol is etched on it.
- Tune your radio to the matching frequency. A five-digit number will transmit.
- For the Sword Safe specifically, you’ll also need the Sword document from the Waiting Room on B3 — it’s a letter-to-number cipher, since the transmitted code needs converting into letters before the safe will accept it.
- Enter the converted code into the keypad.
Because these frequencies and codes reset every save, don’t copy a number from a video or forum post — walk through the steps yourself with your own documents.
How Do You Solve the Signalis Gas Puzzle in the Incinerator Room?
You’ll need the Incinerator Room Key first, which comes from the Sword Wall Safe above. Inside, a panel shows three dials — CO2, GAS, and O2 — next to a screen with a black line (your current setting) and a red line (the target).
- Pull the lever to see which indicator lights glow.
- An up arrow means that gas level is too high; turn the dial down.
- A down arrow means it’s too low; turn the dial up.
- No light means that dial is already correct — leave it alone.
- Repeat: pull the lever, adjust, pull again, until nothing lights up.
Once solved, open the furnace to collect the Fire Key, one of the elemental keys needed for the 5-lock door in the Waiting Room.
How Do You Solve the Signalis X-Ray Room Puzzle?
The X-ray machine itself isn’t the puzzle — it’s step one of a three-part item hunt for the Earth Key.
- In the Imaging Room, examine the X-ray machine and zoom in on its monitor to reveal a dot-and-line pattern etched onto a card.
- Drop down to B4, head into the Flooded Corridor, then the Flooded Store Room, and grab the Blank Key Card.
- Climb back to B3 and go to the Office, where you’ll find a Card PC.
- Insert the Blank Key Card, select “Define Pattern,” and recreate the exact pattern you saw on the X-ray screen.
- Select “Print Pattern” and take the finished card.
Your pattern will look different from anyone else’s screenshot — go off what you actually saw on your own X-ray screen.
How Do You Solve the Signalis Lockpick Puzzle?
Several doors use a four-pin lockpicking minigame instead of a key. Each pin needs to line up with a junction mark at the bottom of the display:
- Adjust one pin at a time — don’t try to eyeball all four simultaneously.
- Start with small click increments; most pins only need minor adjustments once you’re close.
- If a pin is clearly off, try larger jumps first (some players report the third pin in particular needing several clicks before it lines up), then fine-tune from there.
- Recheck every pin after adjusting a new one — moving one can throw off ones you already set.
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How Do You Solve the Shrine Box (Astrolabe) Puzzle?
This is the one most guides mislabel — it’s not a card-matching puzzle, it’s an astronomical alignment puzzle using an item called the Astrolabe.
- Use the computer in the Library on B8 to solve a short sliding-object puzzle and obtain the Astrolabe.
- Visit the Star Map in the Briefing Room, directly across from the Library. It shows Heimat (the star, marked with a diamond) fixed in place, with several planets orbiting it. Note their positions carefully — a screenshot helps.
- Insert the Astrolabe into the Shrine Box in the ADLR Study. It has three rotating rings: an outer ring (a large circle/planet), a middle ring (two lines, representing a paired set of planets), and an inner ring (a small hexagon).
- Rotate each ring to match the corresponding planet’s position from the Star Map, with Heimat fixed at the top.
- Press the button at the Astrolabe’s center to unlock the box and claim the Administrator’s Key.
How Do You Get the Revolver in Signalis?
The Revolver (the “Einhorn”) is a fully missable weapon — nothing forces you to pick it up, so it’s worth deliberately routing for it.
- Get the Flashlight Module first, from the ADLR Bedroom on B8 (you’ll need the Eagle Key to get in). You need this to see inside dark rooms.
- Head to the Shooting Range on B6 and grab the Weapon Case.
- Head to the Protektor Archives on B7 and grab the Hunter’s Key.
- Open your inventory and combine the Weapon Case with the Hunter’s Key to assemble the Revolver.
It’s a slow, high-recoil weapon with limited ammo, but it hits hard enough to be worth the detour for tough encounters.
How Do You Get All Endings in Signalis?
Signalis has four endings: Leave, Memory, Promise, and the secret Artifact ending (plus a False Ending if you stop early). The developers have said there’s no single “true” ending — all four are meant to sit equally. The first three aren’t chosen from a menu; they’re calculated from how you actually played.
Leave, Memory, and Promise — How the Game Decides
Behind the scenes, Signalis tracks three hidden values — roughly tied to Leave, Memory, and Promise — that build up from things like total playtime, how many enemies you kill, how much damage you take, how long you go without healing, and how many NPCs and doors you interact with. Whichever value is highest when you reach the endgame decides your ending. In broad strokes:
- Leave tends to reward a slower, gentler playthrough — talking to every NPC, checking doors, healing right away, taking your time.
- Memory often comes from a fairly average, “typical horror game” playthrough that doesn’t lean hard into either extreme.
- Promise tends to follow aggressive play — high kill counts, absorbing a lot of damage, dying and reloading rather than being cautious.
These thresholds aren’t officially published and have shifted slightly with patches, so treat this as a directional guide rather than an exact formula.
Artifact — The Secret Ending
You cannot get this on a first playthrough. It requires finding three hidden keys across a completed save, each obtained by tuning the radio to a specific frequency in a specific room:
- Key of Eternity — a darkened bedroom on B8, tuned to roughly 065.000, searching the bookcase beneath the wall painting.
- Key of Sacrifice — the Backroom behind the Itou Store in Rotfront, tuned to roughly 240.000, searching the boxes near the white books.
- Key of Love — the Isolation Room in the Worker’s Quarters area.
With all three keys, continue to the padlocked safe you find in the first-person sequence just before the final confrontation and use them there to unlock the Artifact ending.
Frequently Asked Questions
Are Signalis safe codes the same for everyone?
No — with the single exception of the Classroom Safe’s fixed default code (204512), every safe code and radio frequency is randomized per save file. Follow the method, not a copied number.
Can I miss the Revolver permanently?
Yes. The Weapon Case and Hunter’s Key are both optional items, and neither is required to finish the game, so if you skip B6 and B7 you can lock yourself out of it for that playthrough.
Is Signalis available on PS5?
Signalis is available on PC, PlayStation 4, PlayStation 5, Xbox One, Xbox Series X|S, and Nintendo Switch.
Do I need a guide’s exact answer for the Sword or Tree safe?
No — since those codes are randomized, a guide’s specific number will not match your save. What transfers between playthroughs is the process: find the Frequencies document, tune to the matching symbol’s frequency, and (for the Sword safe) decode the number using the Sword cipher document.
What’s the fastest ending to get on a first playthrough?
Most players land on Memory or Promise naturally without trying, since a normal cautious-but-not-perfect first run tends to land in that middle-to-aggressive range. Leave usually takes a deliberately slow, thorough playthrough to trigger.
Guide checked against community-verified sources and the SIGNALIS wiki.