Keys open special loot rooms; each key's description names its Tac-Map grid square, and Lieutenants can drop the key to their own room (official, 5 Oct guide).
Confirmed. Keys exist in MW4 DMZ: they unlock special loot rooms, and every key's description gives a grid location on the Tac-Map and grid coordinates [1].
Where keys come from. A killed Lieutenant may drop a Key to their own special loot room (Lieutenants); other sources are not described yet.
Related looting tips in the guide (not tied to keys there): a door locked from the inside has another way in, and rural areas hide underground entrances. The guide's field report has a key from The Warden opening a sealed room beneath NuriGO Mall that held a plate carrier recipe, rare components and a weapon manual.
Related pages
Sources
- [1]Activision blog, DMZ Deep Dive Part 1: Hajin guide (5 Oct 2026) · callofduty.com · read 9 Oct 2026