Epic Games has confirmed it is using artificial intelligence tools to develop code and features for its widely used Unreal Engine. The move follows CEO Tim Sweeney’s announcement of a “huge pivot” toward “maximum AI acceleration.”
Engineers are using AI to guide development instead of writing most of the code by hand, a process they call “vibe-coding.” For complex tasks, they use tools including Claude Code and Codex.
One project involved a significant rewrite of the engine’s D3D12 rendering layer, completed in about a week. Epic had estimated the work would take three to six weeks. The company says AI tools are helping modernize the engine, improve stability and eliminate bugs that have persisted for a decade.
Epic believes moving too slowly to adopt AI poses a greater risk than facing skepticism about the technology.