Blue Key Card
Key cardReported- Opens
- Blue access door
- Door
- Blue door (room not yet confirmed)
- Found
- 1 Reported just outside B1 (Sector B, Floor 1)
- Loot
- Unconfirmed. In the original DMZ the blue card opened the Data Center; CODM may differ.
Building 21
high danger
Indoor / close quarters
3-player squads
Three indoor floors, four sectors, zero sightlines longer than a hallway.
Building 21 returns from the original PC and console DMZ as a fully indoor map spread across three floors. Expect faster fights, constant AI pressure and corner-to-corner engagements. The in-game tac map labels rooms by sector letter plus floor number (for example B1 = Sector B, Floor 1; C2 = Sector C, Floor 2), and this page uses the same convention.
Added: Season 11 (2025) · DMZ: Recon launch, Dec 11, 2025
Keys & access doors (7 listed)
Red Key Card
Key cardReported- Opens
- Red access door
- Door
- Red door (room not yet confirmed)
- Found
- 1 Reported at C2 (Sector C, Floor 2)
- Loot
- Unconfirmed. Treat as a high-value room until proven otherwise.
Auto Lab NFC Card
NFC cardReported- Opens
- Auto Lab (also called the Bio-Auto Lab)
- Door
- Auto Lab door, Floor 3
- Found
- 1 Reported on the 3rd floor
- Loot
- Lab loot: high-tier gear and crafting items reported.
Archives Room NFC Card
NFC cardReported- Opens
- Archives Room
- Door
- Archives Room, Floor 2
- Found
- 1 Reported on the 2nd floor
- Loot
- Documents / intel items plus mid-to-high tier loot reported.
Maintenance Room NFC Card
NFC cardUnconfirmed- Opens
- Maintenance Room
- Door
- Maintenance Room (floor unconfirmed, shown on F1)
- Found
- No pickup location reported yet.
- Loot
- Unconfirmed.
Conference Room NFC Card
NFC cardUnconfirmed- Opens
- Conference Room
- Door
- Conference Room (floor unconfirmed, shown on F2)
- Found
- 1 Card reported in/near the Conference Room itself
- Loot
- Unconfirmed.
Storage Room NFC Card
NFC cardUnconfirmed- Opens
- Storage Room
- Door
- Storage Room (floor unconfirmed, shown on F1)
- Found
- No pickup location reported yet.
- Loot
- Unconfirmed.
Bosses
Velikan
ReportedBuilding 21 interior
Named as the Building 21 boss in the game's store listing. Drop table in CODM not confirmed; in the original DMZ he dropped a black access card and an RGL-80.
Mechanics
- Every sector has its own stairwell, so rotate floors through the sector you control rather than crossing the map.
- AI density is far higher than Serpent Island. Suppressors and armor plates matter more than range.
- Exfil points are limited indoors: decide your exit before you commit to a key room.
Squad tips
- Call out rooms by sector + floor ("card at C2") the same way the tac map labels them.
- Clear a key room with one teammate holding the hallway; most third parties arrive within a minute of a door opening.
- Put the key card in a safe slot the moment you pick it up so a wipe doesn't erase the run.
Zones
| Zone | Floor | Danger | Notes |
|---|---|---|---|
| Sector A · F1 | Floor 1 | medium | Infil side on most spawns. |
| Sector B · F1 | Floor 1 | high | Blue Key Card reported just outside B1. |
| Sector C · F1 | Floor 1 | medium | |
| Sector D · F1 | Floor 1 | medium | |
| Sector A · F2 | Floor 2 | medium | |
| Sector B · F2 | Floor 2 | medium | Archives Room reported on this floor. |
| Sector C · F2 | Floor 2 | high | Red Key Card reported at C2. |
| Sector D · F2 | Floor 2 | medium | Conference Room reported on this floor (unconfirmed). |
| Sector A · F3 | Floor 3 | high | Auto Lab reported on the 3rd floor. |
| Sector B · F3 | Floor 3 | high | |
| Sector C · F3 | Floor 3 | high | |
| Sector D · F3 | Floor 3 | high |