Announcements and marketing relating to a Call of Duty game have traditionally been around April or May prior to the game's fall release
However, Activision began teasing Black Ops Cold War with an alternate reality game (ARG) in August 2020. Various YouTubers prevalent to the Call of Duty community on YouTube were shipped crates.
Once authorized to open on August 10, 2020, they were greeted by a slide projector, 10 different slides per crate, and a manifest
Starting on August 14, 2020, Black Ops Cold War was marketed, after ciphers being solved, by enticing fans to solve ciphers and puzzles on a website called pawntakespawn.com.
Censorship
CBR.com reported that the teaser trailer had been banned in China due to a one second depiction of the 1989 Tiananmen Square protests. An edited trailer was released instead.