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🏭 Rust · Blue-Card Puzzle

Rust Water Treatment Puzzle

The standout solo run: the only blue-card puzzle with no green-card prerequisite, no scientists reported, and a red card plus ~6 crates. The long sprint from fuse to door is the only real friction.

Current as of the October 2025 'Meta Shift' update · cross-checked vs. rusthelp + Rustafied (June 2026)
Quick answer
Needs Blue Fuse → rewards Red Keycard
S worth-it · Step-by-step ↓ · Loot ↓
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What to Bring

KeycardsBlue
Fuses1 electric fuse — looted only, bring a spare
RadiationHistorically ~25 rad protection; recent reworks may have reduced it. Bring light rad protection and verify on your server. ⚠ verifying
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Step-by-Step Solution

1

Enter the central building through the blast doors — hold E on the wheel to raise them enough to duck under.

2

Head upstairs, place your fuse in the box on the left, and start the timer.

3

Cross to the separate building and go to its second floor.

4

Swipe your Blue keycard at the door and grab the loot — the Red keycard is on the office table in the innermost room.

5

To get out, hit the switch in the back office to power the exit door.

📷 Screenshots coming for these spots:

📷Screenshot to add: The blast-door wheel on the central building
📷Screenshot to add: The fuse box + timer upstairs
📷Screenshot to add: The 2nd-floor blue card reader and the Red card on the office desk
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Loot & Reward

Keycard-door loot respawns every 30 minutes — far faster than open crates, so a puzzle you can reach is renewable income.

No green card needed here — this is the fastest way to a red card if you've already got a blue.
Run it on repeat: keycard-door loot respawns every 30 minutes.

Rust Water Treatment Puzzle FAQ

Do you need a green card for Water Treatment?
No — it's the only blue-card puzzle that skips the green step. Just a Blue keycard and one fuse.
What does Water Treatment give you?
A Red keycard plus around six crates in the reward room — the most efficient red-card source for solos.

More Rust puzzles

One down — here's the rest of the ladder.