One of the biggest selling points of Call of Duty: Warzone is that it's free to play. As long as you have an Xbox, Playstation, or PC that can handle it, you can play it. Though it comes hard-baked into the retail copy of Modern Warfares multiplayer mode, it's a stand-alone download so you can just get to the big player filled mosh pit if you don't have any interest in the other modes.