If you download a claimed "BO2 APK + OBB" from unofficial sites:
: It was removed from most official stores years ago but can still be played if you previously owned it or find legitimate archived APKs. Call Of Duty Black Ops 2 Apk - Obb For Android Offline HOT-
Most "Black Ops 2" APKs found online are either fan-made companion apps containing only maps or information, or Zombies references rather than the full game. If you download a claimed "BO2 APK +