Blood Vials

The Blood Vials are an important set of items featured in the Zombies mode of Call of Duty: Black Ops II, Call of Duty: Black Ops III, and Call of Duty: Black Ops 4. They also appear as a special item within Blackout.

Blackout
A pair of Blood Vials can be obtained as a special item in Blackout, where they are used to obtain Richtofen as a playable character. In order to acquire them, the player must travel to the Asylum with another special item relating to another character mission in the player's inventory. The player can then interact with the blood fountain in the center of the Asylum, causing the item in the player's inventory to be removed and rewarding the player the Blood Vials, to which the player can then pick up. With the Blood Vials, the player must reach a placement of fifth in Solo, third in Duos, or second in Quads. After reaching the necessary placement and finishes the match with the Blood Vials in the player's inventory, Richtofen will be unlocked.