The campaign in Black Ops III is designed to support 4-player cooperative gameplay, allowing for bigger, more open level design and less corridor shooting. In addition, the player can customize their character's gender and appearance. The campaign features its own progression system, featuring unlock tokens which must be used to acquire different weapons and gears as they progress through the campaign. The game features a "realistic" difficulty mode, in which players will get defeated if they are hit by one bullet. Finishing all campaign missions will also unlock "Nightmares" mode, where players can replay the entire campaign with a new narrative, as well as zombies replacing most of the normal enemies.
The multiplayer introduces a new momentum-based movement system, which utilizes thruster packs to allow players to perform slow boosts into the air, as well as perform wall running and sliding, all the while giving players complete gun control. In addition to the Pick 10 class system from Black Ops II, Treyarch implemented a character system called "Specialists", where players can pick from 9 different soldiers, each with either a special weapon or ability unique to them. A new "Gunsmith" feature offers aesthetic variations in weapon attachments, allowing various weapon customization combinations. The Paintshop feature allows players to create their own custom prints onto specific portions of a gun, further emphasizing the depth of customization in the game.
Zombies features a new XP progression system, which allows players to unlock items in a similar fashion to multiplayer and campaign. Unlockable items include "Gobblegums", which grant players with temporary bonuses, and weapon kits that allow players to modify the appearance of the guns in each game. Shadows of Evil was revealed as a new map for the Zombies mode on July 9, 2015 at San Diego Comic-Con International 2015. The map features four brand new characters: Nero the Magician, Jessica the Femme Fatale, Vincent the Cop and Campbell the Boxer as the main cast, and takes place in a new setting called Morg City. "The Giant" includes the original characters, Tank Dempsey, Edward Richtofen, Nikolai Belinski and Takeo Masaki. These characters return from the Black Ops II map "Origins", in their alternate timeline versions. They reappear in the first and second DLC maps, "Der Eisendrache" and "Zetsubou no Shima".