The Buried City Residential Master Key is one of the more valuable keys in ARC Raiders, because it trades a single inventory slot for a guaranteed loot room in Buried City’s apartment blocks. It is also easy to waste if you don’t know exactly where the locked door is.
Buried City Residential Master Key basics
| Property | Value |
|---|---|
| Item type | Key |
| Rarity | Uncommon |
| Name | Buried City Residential Mastery Key (Residential Master Key) |
| Weight | 0.25 |
| Stack size | 1 |
| Sell price | 100 coins |
| Use | Opens certain locked apartment doors in Buried City (notably in Grandioso Apartments) |
| Use count | Single-use; consumed when opening a door |
The key is part of the broader Buried City key set, alongside the Town Hall key, JKV Employee Access Card, and Hospital key. All of them are designed to gate higher-value loot behind specific doors so you have a reason to keep returning to the same districts.
How to get the Buried City Residential Master Key
The Residential Master Key does not have a single fixed spawn. It can drop from general scavenging and is also rewarded from at least one Buried City quest.
| Source | How it works |
|---|---|
| Scavenging (Dam Battlegrounds) | Rare world loot from searchable objects, especially in residential and admin interiors. |
| Ruby Residence (Dam Battlegrounds) | High-density cabinets, drawers, and shelves make this a common place to find random keys. |
| Research & Administration Building (Dam Battlegrounds) | Offices and storage rooms contain many searchable cabinets with a good chance for keys. |
| Quest reward | Granted when completing the Buried City quest “Digging Up Dirt”. |
In practical terms, the most efficient way to farm this key is to loop Dam Battlegrounds, sweeping Ruby Residence and the Research & Administration Building every run:
- Open every cabinet, drawer, and locker in Ruby Residence’s apartments.
- On the second floor of the Research & Administration Building, clear all filing cabinets and office furniture.
- Repeat these routes across multiple raids; the key is a rare drop, so expect some runs with nothing.
Where the Residential Master Key is used (Buried City)
The Residential Master Key is used in Buried City, inside the Grandioso Apartments complex. It opens at least one specific locked apartment room, and the design of the item suggests it can work on multiple residential doors across the map.
| Requirement | Details |
|---|---|
| Map | Buried City |
| District | Grandioso Apartments |
| Building | Larger/northern Grandioso building |
| Floor | Lowest floor / basement level reachable via elevator shaft zipline |
| Door type | Locked apartment door marked for the Buried City Residential Master Key |
The game treats the key as a “master” key that can unlock certain residential doors. One confirmed door is in the basement-level corridor of the taller, northern Grandioso tower. Others may exist, but this one is the most documented and the easiest to route to.
How to reach the Grandioso Apartments locked door
Once you have the key in your inventory, you need to survive a trip to Buried City. Because the key is consumed and can be lost on death, it should ride in a safe pocket until the moment you need it.
Before leaving the hub:
- Equip at least one looting or carry-capacity augment so you can actually take out the items you find.
- Bring a defensive gadget, such as a trip mine, if you want extra security while looting the room.
- Avoid Night Raids unless you are comfortable with higher enemy density and visibility issues.
Once you deploy to Buried City, follow these steps to the door:
- Open the tactical map and set a route to Grandioso Apartments.
- As you arrive, identify the. This is the northern, taller tower called out in community reports.
- Approach this building and head inside or via a low exterior climb to reach an interior level that has an elevator shaft.
- Find the elevator shaft with a rope and use the zipline to descend all the way down to the lowest floor (often described as the basement or “ground zero”).
- Step out into the corridor at the bottom. The locked door for the key is nearby, labelled to accept the Buried City Residential Master Key.
Alternative entry descriptions also mention accessing the bottom floor through a broken window in Grandioso Apartments, but the in-building zipline from the elevator shaft is the clearest and most repeatable path. Either way, your goal is the same basement corridor in the taller/north building.
What you get for using the Residential Master Key
Using the key on the Grandioso door opens a compact loot room with a mix of guaranteed and random rewards.
| Loot type | Details |
|---|---|
| Epic weapon (guaranteed) | One epic-tier gun. Reported examples include the Tempest assault rifle and the Volcano shotgun. |
| Additional weapons | Chance for extra blue (rare) firearms or sidearms on shelves or the floor. |
| Containers and furniture | Filing cabinets and other searchable objects with crafting components, ammo, and trade goods. |
| Security Breach container | Locked “breach and search” reward that requires a specific skill tree unlock to open. |
| Misc. valuables | High-value junk items (like rubber ducks, mustaches, etc.) that add up to notable coin value when sold. |
Several runs through the room show a consistent pattern: the epic weapon drop is reliable, but the exact gun varies. One player might walk out with a Tempest, another with a Volcano shotgun. On top of that, the sheer density of containers and small valuables can easily push the raid’s total bag value past 50,000 coins if you pick your items carefully.
Why you should stash the key in a safe pocket
The Residential Master Key is single-use and disappears after opening a door. It is also lost permanently if you die with it in a regular inventory slot.
| Risk | Impact |
|---|---|
| Death before using the key | Key drops with your body; unless recovered, it is effectively gone. |
| Using the key but dying before extraction | You keep the cleared objective, but lose any loot not in safe pockets. |
| Keeping key in safe pocket | Protects the key from loss until you are physically in front of the door. |
The safest flow is simple:
- Place the key in a safe pocket before deploying.
- Travel to Grandioso Apartments and fully clear immediate threats around the elevator shaft.
- Only move the key into your main inventory if you want to free the pocket for something else after the door is open.
This keeps the key protected from surprise deaths on the way in, and you only risk your haul once you are actually looting the room.
How the Residential Master Key fits into Buried City routing
Buried City is filled with locked interiors that compete for your time during a raid. The Residential Master Key room is strong because it combines reliable weapon upgrades with generic value loot and a Security Breach container for later character builds.
When routing Buried City, Grandioso Apartments pairs well with other key-locked spots on the same map:
- Town Hall key room in central Buried City, with safes and a weapon case.
- JKV Employee Access Card door on the fourth floor of the J Kozma Ventures building near the Space Travel/Parking Garage area.
- Hospital key door off the third-floor locker room corridor in the main hospital building.
Running Grandioso first lets you grab your guaranteed epic weapon quickly, then pivot toward Town Hall or JKV depending on circle position, remaining time, and how much risk you want to take with your new gear.
Used this way, the Residential Master Key isn’t just a one-off curiosity; it becomes a core piece of a repeatable Buried City loot route built around predictable upgrades and efficient extractions.
