Key Takeaways:
- Epic Games EVP of Development Marcus Wassmer has confirmed that engineers are actively vibe-coding features for Unreal Engine 6 and Fortnite using AI tools.
- Wassmer says Epic is “more concerned about the risks of moving too slowly than we are about AI skepticism” and doesn’t think a halfway approach to AI is viable.
- The studio is baking Claude, Gemini, and Codex directly into UE6, with early access planned for late 2027.
- Earlier this month, Epic vibe-coded its entire new Games Launcher and claimed it loads 46% faster than Steam.
- CEO Tim Sweeney has been in an ongoing war with Valve over Steam’s AI disclosure policy, calling it “abhorrent” — even as Epic’s own Fab marketplace requires the exact same disclosures.
If you were hoping Epic Games might pump the brakes on its full-throttle gen-AI push, think again. The company has now explicitly confirmed it is vibe-coding features for Unreal Engine 6, and the person in charge of making the engine is perfectly happy saying so out loud — with zero apologies.
Speaking to This Week In Video Games, Marcus Wassmer, Epic’s executive vice president of development, confirmed not only that AI is actively being used to write code for Unreal Engine today, but that this approach is being extended straight into UE6. “Almost all development happening right now is being done in the dev streams attached to Fortnite, UEFN [Unreal Editor for Fortnite], and UE6,” he said.
Yes, They Are Vibe-Coding the Engine
When asked directly whether Epic is vibe-coding anything related to Unreal Engine, Wassmer didn’t hedge. “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 was careful to frame this as guided iteration rather than autonomous AI generation. “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.” The goal, according to Wassmer, is faster updates and fewer bugs — engineers setting direction, AI handling execution volume.
On the wider question of AI skepticism — workers worried about jobs, developers worried about plagiarism, communities worried about environmental costs — Wassmer made Epic’s position crystal clear. “We are more concerned about the risks of moving too slowly than we are about AI skepticism.” And then came the line that will irritate the most people: “We don’t think it’s viable to take a halfway approach to AI in development. We think it’s best to just be up front with what we’re doing, share best practices with other developers, and make the best UE6 we can with the best tools available at any given time.”
What Unreal Engine 6 Will Actually Look Like
Epic announced UE6 at State of Unreal back in June 2026, and the AI integration goes well beyond vibe-coding features internally. The company plans to ship Claude, Gemini, and Codex directly into the engine as tools developers can use — positioning them as what Wassmer called “creativity and productivity multipliers” rather than replacements for creative vision. The plan is to build on an “open Unreal Engine 6 MCP foundation,” allowing custom AI integrations on top of what Epic builds in.
UE6 is also merging Unreal Engine 5 and the Unreal Editor for Fortnite into a single unified product, adding a new programming language called Verse, and introducing Scene Graph for easier programming of core game mechanics. Early access is currently targeted for late 2027, followed by a full release 12–18 months later.
The reaction from game developers when UE6’s AI focus was first announced was, to put it gently, not universally enthusiastic. Many in the community pointed out that baking AI generation into the engine itself means developers using UE6 in the future may have little choice but to work alongside these tools, regardless of their own views on gen-AI.
The Vibe-Coded Launcher That Started a War With Steam
The UE6 confirmation isn’t coming out of nowhere. Epic has been methodically signalling this pivot for weeks. On October 14, CEO Tim Sweeney announced a “huge pivot underway at Epic, moving developers around to retool for maximum AI acceleration.” That same day, Epic launched a preview of its entirely rebuilt Games Launcher, described memorably in its own blog post: “Programming is hard. So, instead of doing that, we vibe coded a new Epic Games Launcher.” The company claims it loads 46% faster than Steam on a cold start.
There’s a layer of irony worth flagging here. Epic laid off over 1,000 employees back in March 2026, with Sweeney insisting at the time that the cuts “aren’t related to AI.” The community connected the dots anyway, and the subsequent AI-first announcements haven’t exactly cleared the air.
Tim Sweeney vs. Steam’s AI Disclosure Policy
Running parallel to all of this is an ongoing public argument between Sweeney and Valve over Steam’s AI disclosure requirements. Steam asks developers to declare when their games include AI-generated content — artwork, writing, sound, localisation — so that players can make informed purchasing decisions.
Sweeney has been extremely vocal in his opposition. On October 23, responding to a post arguing that AI disclosures are “absurd in 2026,” he wrote: “Forcing developers to write a political statement to be used against them by the hate mob they’re helping organize is abhorrent.” He’s previously called the policy “really irresponsible” of Valve and compared the disclosure label to a “Scarlet Letter.”
The counter-argument that’s made Sweeney look particularly awkward here: Epic’s own Fab asset marketplace requires AI disclosures from sellers. The same kind of transparency Sweeney is calling “abhorrent” on Steam is a policy his own company enforces on its own platform. Valve, for its part, has stayed completely silent throughout — which is probably the correct move when your competitor is making the argument for you.
What This Means for Developers and the Industry
Epic’s position matters enormously because Unreal Engine is one of the two dominant engines in the industry. When Epic decides that gen-AI is baked into the engine’s future — not as an optional plugin, but as a core part of how UE6 is built and how developers will work with it — that shapes the direction of a huge portion of the industry. Studios that want to use UE6 will be working inside an environment built on AI-generated code and AI-assisted tools, whether they like it or not.
Wassmer’s framing of “being up front about what we’re doing” is an interesting one. Epic’s transparency about the AI pivot is genuinely unusual in an industry where many studios are quietly using these tools without public acknowledgement. Whether you read that transparency as refreshing honesty or unrepentant provocation probably depends entirely on where you stand on gen-AI to begin with.
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