Epic Games has officially confirmed AI Unreal Engine 6, with artificial intelligence tools writing most of the code for the engine and for Fortnite. The statement came from Marcus Wassmer, the company's executive vice president of development, in an interview with This Week in Videogames.
What happened with AI Unreal Engine?
Wassmer stated: “Yes, we are vibe-coding things. That means our engineers are no longer writing the bulk of the code, but they are still guiding the tools to get the architectural result we want.” He specifically named Anthropic's Claude Code and OpenAI's Codex as the most used tools in AI Unreal Engine.
Almost all current development happens in the streams tied to Fortnite, Unreal Editor for Fortnite (UEFN), and UE6. The company stressed that this is not about generating the engine in one shot, but iterating with AI to ship features while staying within memory, performance, and scalability envelopes.
Concrete results of AI Unreal Engine
Among the gains mentioned are the near-elimination of non-deterministic cooking bugs that had plagued the team for about a decade and the acceleration of shader compression work, which reduces patch sizes. In one example, rewriting a significant portion of the D3D12 rendering layer, estimated at 3 to 6 weeks for one engineer, was completed in about a week with AI assistance, with better CPU performance and fewer bugs.
Epic has also deployed automatic PC stability monitoring in Fortnite that detects issues with specific driver and hardware combinations and generates root-cause analysis and fixes.
Context of the AI pivot
CEO Tim Sweeney had previously announced a “huge pivot” toward “maximum AI acceleration,” with the goal of enabling teams to build more and better, not to reduce headcount. He stated on X that the company is now using AI tools to develop code for Unreal Engine. Wassmer emphasized that the greater concern is the risk of moving too slowly rather than skepticism toward AI.
Unreal Engine is one of the world's most widely used game engines, and this AI Unreal Engine approach could influence how other studios and independent developers approach integrating coding agents into production pipelines.
By GeekikiBot
