// PC GAMER — GAMING
'Yes, we are vibe-coding things': Epic confirms it's using AI tools to code Unreal Engine 6, Fortnite, and more
'We are more concerned about the risks of moving too slowly than we are about AI skepticism.'
When you purchase through links on our site, we may earn an affiliate commission. Here’s how it works.
You won't catch me venturing deep into the coding mines, but even so, thinking about the comment-less form AI-assisted code can often take still gives me a stress headache. So you can imagine my reaction when Tim Sweeney recently confirmed via X, "Yes, we are now using AI tools to develop code for Unreal Engine."
This is unsurprising given that, in an Unreal Engine 6 blog post back in June, Epic’s executive VP of development Marcus Wassmer wrote that the company had "opened up pretty broad usage for code generation and AI analysis across our backend, engine, and game development engineering teams." More recently, Wassmer offered a follow-up statement to This Week in Videogames, saying, "We are more concerned about the risks of moving too slowly than we are about AI skepticism."
"Yes, we are vibe-coding things," Wassmer elaborates in his most recent statement, "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. We’re not ‘one-shotting’ the engine; we’re iterating with AI to ship features developers want and keep the engine within the memory, performance, and scalability envelopes."
This all follows comments made by Sweeney earlier this week, in which he came out against Steam's AI disclosure statements, claiming that they are "just as partisan as mandatory political essays." The week before, Epic had announced an AI game jam (shortly before walking back the AI requirement), and the week before that the company said it had "vibe coded the Epic Games Launcher to be faster than the other guy."
Wassmer added in his statement yesterday, "As we mentioned back at Unreal Fest in Chicago on stage and in interviews, we are definitely using AI to develop code and features for Unreal Engine. Almost all development happening right now is being done in the dev streams attached to Fortnite, [Unreal Editor for Fortnite], and UE6.”
@mattworkman Forcing developers to write a political statement to be used against them by the hate mob they’re helping organize is abhorrent.October 23, 2026
Epic is using a number of AI tools, though Wassmer specifically mentions Claude Code and Codex. "[These tools are] helping across a broad spectrum of development, with some particularly big recent wins being almost the complete elimination of non-deterministic cooking bugs which we’ve been fighting for a decade and an acceleration of work related to compressing shaders which both significantly reduce patch sizes," Wassmer says, "[Other wins include] a rewrite of a significant portion of the D3D12 rendering layer (which I estimated as needing three to six weeks of work for a single engineer, but the work was actually completed in about one week with a nice win on CPU time and fewer bugs)."
Throughout his full statement, Wassmer repeatedly touts the efficacy and efficiency gains Epic has made by using AI tools. He also argues that this is simply the shape of things to come for game and software development, adding that "The best way to counter any [AI] skepticism is through the quality of the games and tools we’re able to deliver."