Unlock all 37 unique Calling Cards by completing secret challenges that are hidden amongst every mode in Call of Duty: Black Ops 4.
Source: IGN.com COD Black Ops 4: How To Complete All Dark Ops Challenges
Unlock all 37 unique Calling Cards by completing secret challenges that are hidden amongst every mode in Call of Duty: Black Ops 4.
Source: IGN.com COD Black Ops 4: How To Complete All Dark Ops Challenges
