Epic uses AI coding for Fortnite and Unreal Engine 6

Epic Games has confirmed it is expanding its use of generative AI across Fortnite, Unreal Editor for Fortnite and Unreal Engine 6. Marcus Wassmer, executive vice president of development, said this in an interview with This Week In Video Games.

Wassmer said the company is using AI to develop code and features for Unreal Engine, and that the work extends to the next numbered version of the engine. He added that almost all development now happens in the dev streams tied to Fortnite, UEFN and UE6.

Asked whether Epic is vibe-coding work on Unreal Engine, Wassmer answered plainly: yes. He said engineers no longer write the bulk of the code, but still guide the tools toward the architectural result the company wants.

He described the process as iterating with AI rather than producing the engine in one pass. The aim he gave is to ship features developers want while keeping the engine within its memory, performance and scalability limits.

Wassmer said the AI tools would help Epic release updates faster and with fewer bugs. He also said the company is more worried about moving too slowly than about AI skepticism.

He rejected a partial approach to AI in development. Instead, he said Epic wants to be open about what it is doing, share practices with other developers, and build the best UE6 it can with the tools available at the time.