One of the best times to jump back into Call of Duty: Black Ops Cold War is when the game is holding a Double XP weekend. During this time, you can quickly level up to unlock new gear and weapons for just doing what you were already doing: playing the game. The most-recent Double XP weekend has kicked off as the Firebase Z map is introduced for Zombies mode, and you can try it out or jump into competitive multiplayer as you see your level climb.