Military Tunnels Rust: Puzzle, Loot & Radiation Guide

The Military Tunnels are one of the oldest and meanest monuments in Rust. They sit underground, they are stuffed with the smartest scientists in the game, and the good loot is locked behind a three-keycard puzzle on a two-minute timer. Clear it and you walk out with elite crates and Advanced Blueprint Fragments. Rush it blind and you feed a pack of NPCs your best gun.

This guide covers everything about the Military Tunnels in Rust: what the monument is, the full keycard puzzle step by step, how many fuses and cards you need, how much radiation protection to bring, the loot you can expect, the scientists that guard it, and whether it is even worth running. Every number here is checked against the live monument data, not copied from a five-year-old guide.

• What it is
• Quick facts
• The puzzle
• The scientists
• Radiation & gear
• Loot
• Is it worth it
• Where it spawns
• FAQ

What are the Military Tunnels in Rust?

The Military Tunnels are a large underground Rust monument: a concrete-and-rock complex burrowed into a hillside, with a train-track entrance, a maze of tight corridors, and a locked laboratory at its heart. It was one of the very first “puzzle” monuments Facepunch ever built, added all the way back in Devblog 89 on 3 December 2015, and it was rebuilt again in Devblog 196 when the whole layout got a level-design refresh and the scientists learned to open doors and patrol.

In progression terms it is a Tier 3, endgame monument. That puts it in the same bracket as Oil Rig, Launch Site and the Nuclear Missile Silo: a red-keycard destination you hit once you already have a rifle, armour and meds. What sets the Tunnels apart is the fighting. Almost everything happens indoors, in cramped tunnels where a scientist can be around any corner, so it plays less like a loot run and more like a firefight with a loot reward at the end.

Military Tunnels quick facts

Here is the full stat line for the monument, pulled from the current in-game monument data rather than an old wiki snapshot.

Two things jump out. First, this is the only common procedural monument that gates its best loot behind all three keycards at once, which is why players search for the Military Tunnels puzzle more than almost any other. Second, the radiation is genuinely mild for a red-card site, so you do not need to over-gear on rad protection. The danger budget goes almost entirely into surviving the scientists.

How to do the Military Tunnels puzzle

This is the part everyone wants: how do you actually run the Military Tunnels puzzle? You need one Electric Fuse and one of each keycard (green, blue and red). The whole thing is on a clock, so read the steps once before you go in.

1. Insert the Electric Fuse. Find the fuse box near the entrance and slot in a single Electric Fuse. A red light appears on the timer switch to its right. The fuse itself wears down and expires after about three minutes, so do not dawdle.
2. Flip the timer switch. Hit the switch next to the fuse box. The light turns green and the keycard readers power up for roughly two minutes. From this moment the clock is ticking on the whole run.
3. Swipe GREEN at the Storage door. Go through the gap in the fence on your left and head left, then swipe your green card on the door marked “Storage” across the train tracks.
4. Swipe BLUE at the Laboratory door. Continue deeper to the blue door marked “Laboratory” and swipe again. This opens the route toward the monument’s core.
5. Swipe RED, loot, and sprint out. The final red door sits behind the blue one and has a short timer of its own. Swipe it, grab the elite crates inside, and take the quick exit on your left before everything reseals.

You do not strictly need the green and blue cards to physically reach the red door on some layouts, but the intended, safe route runs green to blue to red, opening each section as you go. If you are card-poor, remember a green keycard is about 15 scrap at Bandit Camp and a blue is about 100 scrap at Outpost, while the red card is loot-only from other red-tier monuments.

The tunnel scientists (why it is so hard)

The Military Tunnels are defended by around 30 elite scientists, and these are not the sleepy NPCs you meet at a road-side Radtown. They are the same high-tier AI you fight at Launch Site and the Oil Rigs: they patrol set routes, open doors, break down barricades, and push you in a group instead of standing still to be shot.

Their loadout pool includes the LR-300, SPAS-12 shotgun, MP5A4, M92 pistol and F1 grenades. In the tunnels’ tight corridors the shotguns and grenades hurt the most, because you rarely get the long sightlines that would let a rifle out-range them. Come in with a proper rifle, a full armour set, and more medical syringes than you think you need. Peek corners, use doorways as cover, and let them come to you rather than sprinting into a room full of them.

Radiation: how much protection you need

Good news: radiation at the Military Tunnels is light for a red-card monument. The median level sits around 11, peaking at about 26 in the deepest rooms. That means you do not need to build a full rad tank to survive it, which surprises players who assume every endgame monument bakes you alive.

The cleanest answer to “how much radiation protection do I need for Military Tunnels?” is a Hazmat Suit, which gives 50% radiation protection and makes the whole complex a non-issue. If you would rather run combat armour, roughly 25% radiation protection (a coffee-can helmet plus a road-sign jacket and kilt) is enough to shrug off the median, and you will only feel the deepest rooms briefly. Either way, pack anti-rad pills as a backup and spend your gear budget on syringes, because the scientists will chew through your health far faster than the rads will.

Loot: what the Military Tunnels drop

A red-card monument pays like one. The headline prize is the cluster of elite crates behind the red door (RustHelp counts up to six at the monument), which are the reason you run the puzzle at all. On top of those you get military and normal crates scattered through the complex, medical and food crates, 14 loot barrels, and Diesel Fuel collectables.

One detail a lot of guides get wrong: the Military Tunnels do have a recycler on site (one of them). That is a big deal, because it means you can smash barrels, recycle the components into scrap right there, and walk out lighter without a trip to a safe zone. Between the elite crates and the Advanced Blueprint Fragments, a clean run is one of the better scrap-and-blueprint hauls available before you own aircraft.

Is Military Tunnels worth running?

It depends on your gear and your group. The Military Tunnels sit at an awkward spot on the risk-versus-reward curve: the loot is genuinely good, but the fight is one of the hardest PvE experiences in the game, and because it is not a safe zone, you can also get third-partied by other players who hear the shooting.

Run it when you already have a rifle you can afford to lose, a full armour set, a stack of syringes, and ideally a friend. In that state the elite crates and Advanced Blueprint Fragments are well worth the ammo. Skip it when you are freshly geared and cannot replace what you are carrying, or when you would be better served by a quieter loot loop. For pure scrap efficiency, a road-and-barrel run with the recycler is safer, and monuments like Oil Rig often give a cleaner risk profile. The Tunnels are a monument you clear because you want the fight and the top-tier crates, not because they are the safest scrap per hour.

Where the Military Tunnels spawn

The Military Tunnels are a large monument, which means they take up a lot of the map and do not appear on every seed. On smaller procedural maps (roughly under a 3500 seed size) the game skips the biggest monuments, the Tunnels included, to leave room for building. On a standard 4000-plus map you will usually find them, but not always, so check your server map or a map viewer before you set out with three keycards in your pocket.

Because they are underground, the entrance is a tunnel mouth cut into terrain, not a tall landmark, so they are easy to run past. Look for the train-track approach and the fenced entryway. And a quick note for console players: the Military Tunnels were re-added to Rust Console Edition in late 2025 “by popular demand,” so this same puzzle and loot loop applies there too, with a few backend tweaks.

Military Tunnels FAQ

Sources

• Facepunch, Devblog 89, for the monument’s original addition date (3 December 2015).
• Facepunch, Devblog 196, for the Military Tunnels level-design refresh and the scientist AI changes (opening doors, patrolling).
• RustHelp, Military Tunnel monument page, for the tier, radiation levels, recycler, crate and barrel counts, scientist count and no-build area.
• Corrosion Hour, RUST Military Tunnel Monument Guide, for the scientist loadouts and radiation approach notes.
• Rustafied, Monument Puzzles: Advanced Red Solutions, for the keycard and fuse puzzle sequence.
• whenisforcewiperust.com monuments guide, red keycard guide, Hazmat Suit guide and blueprints guide for the cross-referenced game data.