The Buried City Residential Master Key is one of the more confusing items in Arc Raiders. It drops on a different map than the one it’s used on, the in-game description is vague, and Buried City’s apartments are full of doors that never respond to the prompt. This walkthrough focuses on two things: where the key reliably appears, and the exact door it opens in Buried City.
Buried City Residential Master Key basics
| Property | Details |
|---|---|
| Item name | Buried City Residential Master Key |
| Type | Key (consumable) |
| Weight | 0.25 |
| Vendor value | 100 |
| Primary use | Unlocks a high-tier loot apartment door in Buried City |
| Map where it drops | Dam Battlegrounds (loot containers) |
| Map where it is used | Buried City |
| Consumption | Single-use; disappears when you unlock the door |
Like other keys in Arc Raiders, the Residential Master Key is lost if you die with it in your inventory. Once you use it on its matching door, it is consumed and cannot be reused.
How to get the Buried City Residential Master Key (Dam Battlegrounds)
The key does not spawn in Buried City itself. Instead, you have to pull it out of the Dam Battlegrounds map and then carry it into a Buried City raid.
There are two standout places worth hitting repeatedly:
| Location (Dam Battlegrounds) | What to search | Notes on drops |
|---|---|---|
| Ruby Residence | Cabinets and other indoor containers | Known to spawn random keys; Residential Master Key can appear here but may take several runs. |
| Research & Administration building | Containers on upper floors, especially second floor | General key farm; Residential Master Key is one of several possible random key drops. |
Keys in Arc Raiders are random drops from containers like lockers, cabinets, boxes, and similar stashes. There is no fixed guaranteed spawn for the Residential Master Key; Ruby Residence and the Research & Administration building are simply dense in searchable containers, which makes them efficient key farms.
Practical farming loop:
- Load into Dam Battlegrounds near either Ruby Residence or the Research & Administration building.
- Sprint the route, opening every cabinet, locker, desk, and box that would make sense for storing small items.
- Extract as soon as you have the key or have cleared most of the building; repeat as needed.
Because keys are single-use and lost on death, it’s worth putting one in your safe pocket before you leave Dam Battlegrounds if you plan to take it directly into Buried City on your next raid.
Where to use the Buried City Residential Master Key (Grandioso Apartment)
Once you have the key safely extracted from Dam Battlegrounds, load into Buried City. The Residential Master Key is used on a specific apartment in Grandioso Apartment.
Finding Grandioso Apartment in Buried City
The sources line up on two slightly different but compatible descriptions:
- Some players refer to a locked door in the “north building of Grandioso Apartments,” reachable by dropping into an elevator shaft.
- Other guidance points to Grandioso Apartment in the southern part of the Buried City map, accessible from the ground floor through a broken window, with the locked room immediately to the left.
In practice, the Residential Master Key is tied to Grandioso Apartment as a residential complex on the west/southwest side of Buried City. Internally, the key opens a specific apartment room off a low-level corridor. The key will only prompt on that room’s door; it will not work on random “scarce loot” doors elsewhere in the city.
Detailed route to the Grandioso Apartment door
Use this route once you are in Buried City with the key in your inventory:
- Head toward the Grandioso Apartment icon. On your compass and map, look for the apartment icon associated with the Grandioso complex on the western side of Buried City. Move toward that cluster of buildings.
- Identify the Grandioso Apartment structure. You are looking for a multi-story residential block with multiple entry points. The building is part of the “Grandioso” named area on the map.
- Enter through the broken ground-floor window. On the ground level of Grandioso Apartment there is a shattered window that serves as a low-profile entry. Climb or vault through this opening rather than using noisier or more exposed entrances.
- Turn left from the window inside. Once you’re through the broken window and into the internal corridor, turn left. A short distance down that hall you will see a locked apartment door that responds to the Residential Master Key.
- Use the Residential Master Key on the door. Interact with the door; the prompt will consume the key and unlock the room.
Alternative reports mention a locked door reachable by jumping down an elevator shaft to “ground zero” in the north Grandioso building. That seems to describe another way of reaching the same lower level area in one of the taller Grandioso blocks. If you prefer that route, locate the taller, northern Grandioso building, find the elevator shaft, drop carefully to the basement, and look for the locked door on that level.
What’s behind the Residential Master Key door
Unlocking this room is meant to be a meaningful reward for carrying the key safely across maps. Inside the Grandioso Apartment loot room you can expect:
- Epic weapon: players consistently report an epic Tempest assault rifle inside this room.
- Reward container: a Security Breach–type reward container that can roll additional high-value loot.
- Supplementary loot: typical room spawns such as ammo, consumables, or smaller containers.
The exact loot rolls can vary run to run, but this room is tuned as a high-tier reward compared with normal apartments in Buried City.
Combat and risk around Grandioso Apartment
The Grandioso area is not a safe stash. Expect both AI and player pressure:
- ARC presence: Buried City’s residential blocks are frequently patrolled by ARC units. They can pin you down in the narrow corridors leading to the Grandioso room.
- Other raiders: Grandioso’s reputation as a loot-heavy area means other players often path through or camp nearby.
To reduce the odds of losing your key before you ever use it:
- Approach Grandioso from cover-heavy routes rather than sprinting across open streets.
- Clear immediate ARC patrols outside before committing to the interior.
- Once the door is open, loot quickly and decide whether you can safely stay in the area or should rotate toward an extraction path.
How the Residential Master Key compares to other Buried City keys
Buried City has several location-specific keys, each tied to a distinct building or function:
| Key | Primary building/area | Main benefit |
|---|---|---|
| Buried City Town Hall Key | Town Hall (central Buried City) | Opens a locked room on the north side of Town Hall with safes and a weapon case. |
| Buried City Residential Master Key | Grandioso Apartment (western Buried City) | Opens a single high-tier apartment room with an epic Tempest rifle and a reward container. |
| Buried City JKV Employee Access Card | J Kozma Ventures building (Space Travel / parking garage area) | Unlocks a steel door on the upper floors, giving access to secure loot in the corporate building. |
| Buried City Hospital Key | Hospital (upper floors) | Opens a door near the third-floor locker room, leading to a loot-rich medical room. |
The Residential Master Key sits in the same tier as Town Hall, Hospital, and JKV keys: each opens one specific, dense loot room rather than a general shortcut or traversal option. All of them benefit from the same pattern: farm on Dam Battlegrounds, then route through Buried City to the matching door while managing PvE and PvP risk.
If you have multiple Buried City keys at once, it often makes sense to chain their locations into a single raid, but only if you are confident in your ability to survive. Otherwise, prioritize the Residential Master Key door for the guaranteed weapon and reward container, then extract before greed gets you killed.
