Blizzard Entertainment deployed an internal AI image-generation tool called Blizzard Diffusion, used by designers to produce concept art for game environments, characters, and outfits. The tool is a customized version of Stable Diffusion trained on Blizzard-owned art assets rather than images scraped from the internet. Its existence became public in May 2023 after an internal email from Chief Design Officer Allen Adham, reported by The New York Times, described the studio as being on the brink of a major evolution in how it builds games.

Blizzard Diffusion is a fine-tuned version of Stable Diffusion trained exclusively on Blizzard-owned artwork; Chief Design Officer Allen Adham's internal email, reported by The New York Times in May 2023, said it was being used to generate concept art for game environments, characters, and outfits, and named future ambitions including AI-assisted voice cloning, procedurally assisted level design, and autonomous in-game NPCs (non-player characters). Separately, CTO Michael Vance emailed staff warning them not to use Blizzard's intellectual property with external AI image generators. VP of Global Insights Andrew Guerrero told The New York Times that the goal was to remove repetitive and manual tasks so artists could spend more time on creative work. A separate machine-learning tool that Blizzard had patented for generating environmental textures had already been abandoned by the time of the May 2023 announcement because it required too much artist time to be effective. As of early 2026, the Overwatch team's game director Aaron Keller and the World of Warcraft team's franchise director John Hight had both publicly confirmed their teams are not using generative AI for player-facing content.