Epic Games relies on artificial intelligence to build software across Fortnite and Unreal Engine 6

Epic Games has confirmed that it is extensively using generative artificial intelligence to develop code and features across Fortnite, the Unreal Editor for Fortnite, and its upcoming Unreal Engine 6. Marcus Wassmer, the company's executive vice president of development, told This Week in Video Games that human engineers are no longer writing the bulk of the code, though they still guide the systems toward target architectural outcomes. [1][2]

Epic is leaning on tools such as Claude Code and Codex to iterate rather than produce an engine in a single pass. Wassmer noted that the tools helped engineers rewrite a substantial portion of the D3D12 rendering layer in approximately one week, an effort he previously estimated would take three to six weeks. He also credited artificial intelligence with accelerating shader compression to shrink patch sizes and virtually eliminating non-deterministic cooking bugs that had persisted for a decade. [1][2]

The development strategy comes as Epic brushes off wider industry skepticism regarding job security, environmental costs, and plagiarism, with Wassmer emphasizing that the company worries more about moving too slowly. Epic previously admitted to vibe-coding its launcher to outpace rival platform Steam, while chief executive Tim Sweeney recently denounced Steam policies that require developers to disclose their use of generative tools. [1][2]