I also felt liberated by the fact that there’s no limit on how many mid-game perks you can have, so unlike in previous Zombies modes you never need to second-guess whether it’s worth grabbing one or not. Those are persistent upgrades, but within each match there’s also weapon rarity to keep an eye on: as you progress deeper and purchase more weapons, a higher rarity level denotes better attachments and damage, which gives you motivation to check every gun you come across to see if it’s better than what you have instead of basically forgetting about the loot system after a certain point.

Perhaps most notably are all of the Skills: Field Upgrades are special attacks you charge up over time, like the Frost Blast that slows zombies and Weapon Classes let you specialize and upgrade your loadout with new abilities, such as transforming the rifle butt melee hit with R3 into a knife slash for more damage, which very helpfully conserves ammo. The classic Zombies experience gets a handful of other minor new features as well.

Call of duty cold war zombie mode