the campaign, multiplayer, and zombies, while criticizing its technical issues and lack of innovation. It became the best-selling game of 2020 in the US. Gameplay Campaign Call of Duty: Black Ops Cold War campaign allows players to assume a custom character, codenamed "Bell", with the ability to choose their intelligence agency, skin tone, nationality, and gender; as well as different personality traits that provide in-game perks. For the first time since Call of Duty: Black Ops II, the campaign features multiple endings, dependent on player choice throughout the campaign. Multiplayer Multiplayer features new and returning game modes, as well as maps that accommodate both the traditional 6v6 format, as well as larger 12v12 combat. The game also introduced a new game mode named "Fireteam", which can support up to 40 players. The Create-a-Class system from Modern Warfare returns, with two major differences: field upgrades are implemented as part of class loadouts, and each class has a wildcard choice out of four possible ones: Gunfighter (allows up to 8 primary weapon attachments), Perk Greed (allows 2 perks from each perk type for a total of 6 usable perks), Danger Close (double grenade equipment), or Lawbreaker (allows mixing and matching any weapon/perk type in any slot). Like Modern Warfare, Cold War also support cross-platform play and cross-platform progression. Following an update, the progression system for multiplayer is integrated with Call of Duty: Warzone, allowing for a unified level system across Cold War, Warzone and Modern Warfare. In addition, Operator characters and weapons from Cold War are also added to Warzone to be used alongside Modern Warfare Operators and weapons, though the multiplayer modes remain separated and do not share Operators and weapons. Zombies Zombies features a new storyline titled "Dark Aether" which expands on the original Aether story, concluded in Black Ops 4, while also staying true to the main narrative of the campaign. Instead of playing as predefined characters, players can take on the role of Operator characters from Multiplayer, as part of a CIA response team codenamed "Requiem". Progression from Multiplayer is shared with Zombies, as players are able to use any weapon to start a Zombies match, alongside Gunsmith, scorestreaks and field upgrades, in addition to returning mechanics such as wallbuys, the Mystery Box, Pack-a-Punch and past fan-favorite Perks. For the first time in Zombies, players can opt to "exfil" the map, which will put them in a difficult