The company this week said the Double XP Weekend will be available between Fri., May 20 at 10AM PST and Tues., May 24 10AM PST.
The Double XP Weekend was delayed following an outage of the Playstation Network. The service was restored May 15.
First Strike includes four all-new multiplayer maps, including Berlin Wall, Discovery Stadium, and Kownloon.
In addition, the DLC includes a new Zombie map called Ascension.
Activision Blizzard in Dec. said Call of Duty: Black Ops has generated $1 billion in sales worldwide.
Activision Blizzard in Nov. will sell Call of Duty: Modern Warfare 3, the next installment in the FPS franchise.