Call of Duty: Black Ops 4 is, in a way, three games. There's the standard multiplayer modes, Blackout (the battle royale mode), and Zombies mode (which is a zombies mode). A new version of the game called Battle Edition snaps a piece off like so much Kit-Kat and offers it to you at a reduced price on Battle.net. Call of Duty: Black Ops 4 Battle Edition contains the Blackout and standard multiplayer modes for $30 (until January 6, when it'll cost $40). Zombies not included.
"The Black Ops 4 Battle Edition offers the full Multiplayer and Blackout experiences, and is compatible with all existing copies and online lobbies for those modes on PC," reads the announcement on the Activision Blizzard site. "For fans interested in getting their hands on even more, an upgrade to the Digital Standard Edition on PC—includes Zombies mode, 1,100 Call of Duty Points and Digital Edition bonus items—will also be available for purchase."
Will we see more mixing and matching of CoD modes in the future? Maybe Blackout and Zombie modes will be packaged together at some point, or perhaps battle royale will eventually be sold completely separately (which I'm sure lots of people would want). For now, you can read more details at the Activision Blizzard site.
