Call of Duty DMZ Key Locations Guide: Where to Use All 10 Serpent Island Key Cards

Every Call of Duty DMZ key location on Serpent Island: all 10 key card secret rooms with step-by-step directions, loot tips, and routing advice.

Ten hidden rooms. Ten key cards. One island packed with unguarded loot. Tracking down every Call of Duty DMZ key location on Serpent Island is one of the most profitable — and most overlooked — ways to gear up in a single deployment. Each card opens a secret room stuffed with valuable items, and according to community reports, unlocking a room triggers a 30-second priority window during which only you can loot it. Not your squadmates. Not random operators. Just you.

This guide breaks down all 10 Call of Duty DMZ key locations in detail: how the cards work, where every room hides, what to grab first, and how to chain multiple rooms into one efficient run.

How Key Cards Work in DMZ

Before anything else, understand the mechanics. A key card is useless sitting in your backpack — you have to equip it before you approach a locked door. Open your inventory, click the key icon, and select the card you plan to spend. Per player experience, an unequipped card simply won't trigger the door.

Getting your hands on cards comes down to two paths:

Leveling up — cards unlock as your account progresses, rewarding regular play.
Buying them outright — head to the black market vendor and browse the special items section. The community refers to this shop as the Corona Shop, and it's the fastest option if you need a specific card right now.

Based on community reports, Serpent Island cards come in two tiers: NFC Silver (eight of the ten cards) and NFC Gold (two cards). Gold rooms cluster near the island's crown vaults and tend to pay out the heaviest.

Method	How It Works	Best For
Account leveling	Cards unlock automatically as you progress	Players who grind deployment after deployment
Black market purchase	Check the special items section of the black market shop	Anyone who wants a specific card immediately
Equipping before use	Click the key icon in your inventory and select the card	Everyone — doors stay locked otherwise

For seasonal updates that can shift map layouts or vendor inventories, keep an eye on the official Call of Duty website before planning your routes.

All 10 Serpent Island Key Card Rooms at a Glance

If you only bookmark one section, make it this one. Every Call of Duty DMZ key location on the island starts with a landmark — a vault, a tower, an extraction point — and the room is never far from it.

#	Key Card	Landmark to Find	Secret Room Location
1	Port NFC Silver	The house at the port	Second floor of the house
2	Hotel NFC Gold	Crown vault at the Serpent Island Hotel	Down the double zip line route past section 4 (full steps below)
3	Train Station NFC Silver	Small house near the paid extraction point by the North Serpent Island Hotel	Inside the small house — hard to miss once you're in the area
4	Kurana Ship NFC Gold	Crown vault on the ship	Immediately to the right of the vault
5	Kurahana Ship NFC Silver	Boat extraction point	Second floor, next to the character poster
6	Kurahana Base NFC Silver	Base entrance marked with the number 1, right side	Straight ahead, just past the staircase
7	Serpent Town NFC Silver	Central town building	Past the zip line, straight ahead from the landing
8	Business District NFC Silver	House in the South Serpent Island Hotel area	First right inside the house
9	Serpent's Fortress NFC Silver	The fortress vault	Adjacent house — not the vault building — down the interior stairs
10	Refinery NFC Silver	The refinery tower	Right-hand side of the tower

All directions reflect current player experience with the Serpent Island build, so expect minor repositioning if a patch reshuffles interiors.

Step-by-Step Directions for the Trickier Rooms

Most rooms above are find-and-open. Three, however, demand real navigation, and fumbling them mid-raid costs you the priority window you paid for.

Hotel NFC Gold — Serpent Island Hotel

Start at the crown vault inside the hotel, then enter the section marked with the number four. From there, follow the vertical route:

Step	Action
1	Enter the hotel section marked with the number 4
2	Move forward, then turn left and ride the first zip line
3	Land, turn left again, and take the second zip line
4	Land, turn left one more time — the secret room door is right there

Three left turns and two zip lines. Practice the route once in a low-stakes deployment and it becomes muscle memory.

Kurahana Ship NFC Silver

Your anchor is the boat extraction. When you're near it, go right, then push straight inside until you hit a staircase. Climb to the second floor and look for the character poster — community members call it the Ring Yoshida poster. The secret room sits directly beside it.

Serpent's Fortress NFC Silver

This one trips people up constantly. The room is near the fortress vault but not inside the vault building. Walk to the neighboring house, head straight through the entrance, turn left, and take the stairs down. The secret room waits at the bottom.

The 30-Second Priority Window: Loot Smart

Here's what makes these rooms special. Per community reports, the moment you open a secret room, a 30-second priority window begins — only the card holder can loot during that time, and teammates can't take anything from the room at all. That exclusivity means every second counts.

Savvy squads assign each player a different card before deploying. Three players hitting three rooms in sequence creates three guaranteed, uncontested loot windows instead of one contested scramble.

Once the room is yours, grab in this order:

Priority	What to Grab	Why It Matters
1	High-rarity weapons and attachments	Immediate power spike for the rest of the run
2	Cash, gold, and tradeable valuables	Funds black market purchases and buy-station spending
3	Armor and survivability items	Keeps you alive long enough to hit the next room
4	Bulk filler items	Tops off your bag before you extract

Routing: Hit Multiple Rooms Per Run

Carrying one card per deployment is leaving money on the table. Because the ten Call of Duty DMZ key locations cluster into geographic groups, two or three cards per infil is the sweet spot — enough payout, without overloading your bag before you reach an exit.

Cluster	Key Cards to Carry	Route Logic
Hotel corridor	Hotel NFC Gold, Train Station NFC Silver, Business District NFC Silver	Both hotels anchor the zone; the train station house sits near the paid extraction, giving you a natural exit
Harbor duo	Kurana Ship NFC Gold, Kurahana Ship NFC Silver	Both rooms live on or beside the ships — run them back-to-back in one sweep
Industrial loop	Kurahana Base NFC Silver, Refinery NFC Silver	Enter the base at marker 1, clear the room, loop out to the refinery tower
Town and fortress	Serpent Town NFC Silver, Serpent's Fortress NFC Silver, Port NFC Silver	Central building, fortress, and port house form a tight triangle

A few routing habits worth building:

Buy cards before you deploy. The black market's special items section means you never have to hope for a drop.
Use the paid extraction when heavy. The exit near the North Serpent Island Hotel pairs perfectly with the train station room.
Open the hardest room first. If your route includes the hotel zip line chain, do it while your bag is empty and your squad is fresh.
Stack priority windows. Spreading cards across your squad keeps every looting phase uncontested.

Frequently Asked Questions

Where are the Call of Duty DMZ key locations on Serpent Island?

All ten secret rooms are tied to landmarks: the crown vaults at the Serpent Island Hotel and the Kurana Ship, the boat extraction at Kurahana Ship, base entrance 1 at Kurahana Base, the refinery tower, and the town, fortress, port, and both hotel districts. The full table above maps each card to its exact room, based on current player experience.

How do I get key cards if I'm new?

Two ways: unlock them by leveling up your account, or buy them directly from the black market vendor — check the special items section of the shop the community calls the Corona Shop. Buying is the fastest path if you're targeting a specific room.

Can my teammates loot the secret room I open?

During the 30-second priority window, no — only the player who used the key card can loot, and teammates can't take anything from the room in that period. The cleanest workaround is coordination: give every squadmate their own card so everyone gets a private window.

Which key cards should I prioritize?

Start with the two NFC Gold cards — Hotel and Kurana Ship — since both sit beside crown vaults and community reports point to them as the richest rooms. After that, carry whichever silver cards match your drop zone using the cluster table above.

Ten cards, ten rooms, and a 30-second guarantee that nobody else touches your loot. Learn the landmarks, chain your clusters, and Serpent Island quietly becomes the most profitable deployment in your rotation.