You can read about how Call of Duty: Black Ops II changes multiplayer class-selection with the introduction of a pick-10 system. It's all explained right here. Or you can just stare at this board game prototype of the system from the creators of the game.
Kotaku · Stephen Totilo
The Lack Of Master Chief Was The Least Of Halo 5’s Campaign Problems
Kinja is in read-only mode. We are working to restore service.