The Outpost in ARC Raiders is a surface base you grow room by room, and each room you add raises your Outpost level. Reaching Level 4 is what lets you push the Research Station and the Gunsmith to their highest tiers, so the upgrade path is tied directly to weapon amplification rather than being pure decoration.
Quick answer: There are four Outpost levels. Level 1 arrives when you finish the Sheltered Retreat Project, then three expansions take you to Level 4, each adding one room for a fixed set of materials.
How Outpost levels work
Your Outpost level is set by its room count: the starting base room is Level 1, and each room you add increases the level by one, up to four rooms. The Outpost unlocks after you reach Raider Level 18 and finish all three stages of Sheltered Retreat.
The Research Station’s maximum level follows your Outpost level, while Gunsmith IV requires the full four-room setup. Adding a room raises the level cap, but its materials don’t cover the station upgrade; you’ll need to pay for each separately.
Outpost upgrade materials for Levels 2, 3 and 4
Each expansion costs a fixed recipe. The cost depends only on which expansion it is, not on which room design you pick, so the look of the room is a free choice.
| Upgrade | Materials |
|---|---|
| Level 1 → 2 | 3 Steel Cable, 20 Sheet Metal, 3 Cable Strippers |
| Level 2 → 3 | 3 Epoxy Buckets, 35 Planks, 3 Hand Drills |
| Level 3 → 4 | 40 Sheet Metal, 3 Laser Levels, 3 Insulation Rolls |
Items already sitting in your Stash count toward each recipe, so check what you own before running raids to farm more.
Where to find each Outpost material
Almost everything you need drops on Pendola Pass, the snow map tied to the Outpost. Sheet Metal and Planks are the easy part, while the component items are the real bottleneck.
Sheet Metal and Planks
Both are common loose loot across Pendola Pass. Celeste also sells them for 3 Assorted Seeds each, which is faster than looting once you have Seeds to spend. Your Seeds come from Scrappy, who caps at 50, so claim them often or you waste the ones he gathers while you raid.
Steel Cable
Steel Cable turns up as loose loot rather than inside containers, most reliably around the Railyard and Freight Terminal and inside the Fallen Emperor. Celeste stocks it too, at 20 Assorted Seeds per unit. Build the room before spending it elsewhere, since ziplines and Snap Hooks also consume Steel Cable.
Cable Strippers and Hand Drills
These two component tools come from zones marked Industrial and Mechanical on any map, including the Pendola Pass supermarket shelves, the Railyard and the Observatory breachables. They are uncommon drops, so plan on several raids if you do not already have spares.
Epoxy Buckets
Epoxy Buckets appear only on Pendola Pass, scattered through the abandoned train cars, on Observatory desks and bins, and near the Railyard. They are flagged as recyclable, so take care not to scrap them by accident.
Laser Levels and Insulation Rolls
Both sit randomly in Pendola Pass high-tier loot areas, reported on the Commissary Supermarket shelves and inside the train cars. Insulation Rolls also turn up inside the frozen loot rooms that you melt open during blizzard Storm Hut events, which spawn rare materials at a high rate.
Rooms you choose at each level
Each expansion lets you add one room, selecting from four designs. Panoramic, Timeless, and Chalet are options for rooms two and three; Studious Room is available only with the final expansion to Level 4. Room placement is permanent, so adjust the camera first and choose where to attach it.
| Room | When available | Furniture slots |
|---|---|---|
 Base Room | Starting room | 42, plus 8 station slots |
 Chalet Room | Rooms 2 and 3 | 22 |
 Timeless Room | Rooms 2 and 3 | 22 |
 Panoramic Room | Rooms 2 and 3 | 22 |
 Studious Room | Room 4 only | 22 |
Research Station upgrades that run alongside the rooms
The Research Station installs with the Outpost and has four levels, each needing a matching number of rooms plus its own materials. Build it in step with your room expansions, since a new room only raises the cap rather than paying for the station.
| Level | Rooms needed | Materials |
|---|---|---|
| I | 1 | 35 Planks, 5 Battered Paperbacks, 3 Mini Pumps |
| II | 2 | 3 Calculators, 3 Raider Logbooks, 5 Skulker Targeters |
| III | 3 | 3 Differential Microphones, 3 Exodus Technical Handbooks, 6 Bully Fragmenters |
| IV | 4 | 3 Thermal Shakers, 3 ARC Data Modules, 1 Frigate Inductor |
A Skulker Targeter comes only from the detached gun half of a destroyed Skulker, not its body. Destroy Bullies around Railroad Junction and Commissary Supermarket to get Bully Fragmenters. The Frigate Inductor and ARC Data Modules are looted aboard the ship during the ARC Frigate event.
What reaching Outpost Level 4 unlocks
With four rooms installed, you can take the Gunsmith from III to IV, which costs 3 Radial Presses, 3 Magnetic Accelerators and 1 Emperor Modulator. The Emperor Modulator is a legendary material that drops inside the Fallen Emperor on Pendola Pass, so you cannot reach Gunsmith IV without one.
Reaching IV with both the Gunsmith and Research Station unlocks the Amplified Research tab and the fifth weapon quality tier. Amplification gives supported guns a branching upgrade tree, with results such as a full-auto Burletta, a scoped Renegade, or a Rattler equipped with a drum magazine and incendiary rounds. At launch, 15 weapons are supported, and more are planned for future updates.
How to confirm an upgrade worked
After committing materials in the Outpost tab, the new room appears attached to your base and your Outpost level ticks up by one. That new level immediately raises the Research Station’s available cap, so the next station tier becomes selectable. Once your fourth room is in and both the Research Station and Gunsmith read Level 4, the Amplified Research tab becomes usable, which is the point where you can start amplifying weapons.
