The Building 21 Key can be found from Supply Drops and Orange Crates in DMZ. Read on to learn about the location of Building 21, how to obtain the key and colored access cards, the secret boss inside, as well as the rewards that you can get from using the key.

DMZ Key Guides
All DMZ Key Locations	How to Find Building 21 Key

How to Find Building 21 Location

Accessed on the DMZ Level Selector Screen

Building 21 is now currently accessible in DMZ by selecting it on the level selector menu before deploying in a DMZ game. Players will be able to select Building 21 as long as they have obtained a DRC Building 21 Access Card and have it stored in their Key Stash.

Accessible Only at Certain Times

Building 21 Cooldown
00:00:00 Building 21 is now live!

Building 21 will only be accessible at certain times. There will be a cooldown timer on the level selector menu indicating the next available time that players can access it in DMZ.

Unlimited Access to Building 21 Bug

Recently, there was a bug that allowed players to access Building 21 an unlimited amount of times even if they only have one access card. The access card was intended to be removed from their key stash after each use but some players seem to still have it in their inventory.

This bug may be fixed once the cooldown timer ends and the building will be re-added in DMZ again.

How to Get Building 21 Key

Obtained From Supply Drops

DRC Building 21 Access card is the key to getting inside the Building 21 in DMZ game mode. The access card can be obtained in Supply Drops by destroying Supply Planes and the Commander HELO Helicopter with the use of SAM Sites (marked with a White Missile icon on your map).

Upon taking down either of the two, the Supply Drop will be marked on your Tac-Map. This does not guarantee that you will always get the Building 21 Key Access Card, sometimes you'll get the Red Access Card instead.

Obtained From Orange Crates

The DRC Building 21 Access Card can also be obtained inside Orange Crates; these are commonly found in Strongholds, Denied Areas, and locked rooms in DMZ - which requires keys to open. Similar to Supply Drops, the Building 21 Key Access Card will appear randomly by chance in Orange Crates.

All DMZ Key Locations and Rewards

Building 21 Colored Access Cards

How to Get Colored Access Cards

Supply Drops and Orange Crates

Similar to the DRC Building 21 Key Access Card, the Red and Blue Access Cards can be obtained from Supply Drops and Orange Crates scattered throughout Al-Mazrah while playing DMZ.

The Green Access Card can be obtained from drilling safes inside Building 21.

To get a Black Access Card, you have to kill Velikan (secret boss inside) or destroy Wheelson, the sentry bot located near the exfil elevators.

Where to Use Colored Access Cards

Color-Coded Secret Rooms Inside Building 21

Color-Coded Locked Rooms contains high-tier weapons and equipment. Colored Access Cards will give you access to the following locations inside Building 21:

Colored Access Cards	Unlock Location
Blue	Security Room Near Data Storage
Red	Security Room Near Office Storage
Green	Storage Room South Side of the First Floor
Black	Lowest floor (Parking Area) - located along the Basement Hallway

Building 21 Boss Fight

Velikan

Velikan is the new secret boss found inside Building 21; an alert notification will pop-up on your screen towards halfway through the DMZ match. Velikan's location will always be at the center room on the second floor of Building 21.

Once confronted, he will relentlessly pursue your squad with a grenade launcher until he is killed. Killing him will drop the Black Key Access Card and a RGL-80 Grenade Launcher - which you can safely store in your weapons stash as a contraband weapon after a successful exfil.

Building 21 Rewards

Chimera

The Chimera assault rifle is now obtainable as a reward found in Building 21 after the release of the Season 1 Reloaded version of the game. Players will need to find and extract the weapon from Building 21 in order to unlock it. Extracting the Chimera allows players to use it as a contraband weapon in DMZ.

Chimera is a weapon that was previously only used in the campaign by Ghost but has now been confirmed to be a new multiplayer weapon.

Chimera Assault Rifle

High-Tier Weapons and Equipment

All Weapon Contrabands and Equipment looted from containers and dead AI inside Building 21 have better stats and more attachments equipped than those found in Al-Mazrah. These weapons can be used the next time you launch a DMZ session, provided that you have succesfully extracted with it prior.

Customizations From Weapon Cases

Extracting weapon cases from Building 21 will unlock and reward you with Blueprints, Charms, Calling Cards, Vehicle Camos, and Emblems.

These rewards are considered rare as you can only obtain them while playing DMZ. All customizations can also be used in Modern Warfare 2's Multiplayer game modes where you can show off your newly customized weapons to other players!

All Building 21 Weapon Cases

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