Black Ops's Escalation map pack will be released on Tuesday, May 3rd.
As part of the ongoing agreement between Microsoft and Activision, it will be exclusive to Xbox Live users first.
The new DLC will feature five new multiplayer maps, including one "unique Zombies experience", according to Major Nelson.
The maps include the roof of a Cuban hotel, an ambushed US military convoy, an abandoned Soviet Russian Zoo and a Russian farm town housing secret WMD facilities.
Escalation will be released on PSN and PC at a later date.