Which Counter-Strike game introduced the Battle Royale mode called Danger Zone?

Counter-Strike: Global Offensive introduced the Battle Royale mode called Danger Zone.

Valve added Danger Zone to Counter-Strike: Global Offensive in December 2018. It placed players on a large map where they searched for weapons, equipment, and cash while surviving against other players. The mode adapted familiar Counter-Strike shooting and movement to a larger last-player-or-team-standing format.

Danger Zone was separate from the traditional competitive bomb-defusal and hostage-rescue experiences. It included features such as a shrinking play area, item collection, drones, and solo or squad-based play. These additions gave Global Offensive a different pace from its classic round-based modes.

Counter-Strike 2 succeeded Global Offensive as Valve’s main Counter-Strike platform in 2023, but the historical introduction of Danger Zone belongs to Global Offensive. The mode is therefore not associated with the original 1.6 or Source releases.