Call of Duty: Black Ops IV is a payed game, which you need to purchase as a disc (physically) for your Xbox One/One S/Series X or digitally on the Microsoft Store, for any Xbox One/Series X|S console.
Can I play the game without an Internet connection? You will need an Internet connection in order to acquire updates. Once the game is fully up-to-date however, you will be able to play in local multiplayer without an Internet connection.
Campaign: The Campaign is solo only but works without an internet connection. Split-screen: Multiplayer You can play up to 4 player split-screen on one PS3 or Xbox 360/Xbox One/Xbox Series Console.