Epic admits AI now writes most of the code for Fortnite and Unreal Engine 6

Epic Games has taken a step that many studios had hinted at but few dared to say out loud: most of the code in its projects no longer comes from the hands of its engineers, but from artificial intelligence tools that those engineers supervise. That is what Marcus Wassmer, the company's executive vice president of development, acknowledged in an interview on the show This Week in Video Games, reported by Eurogamer and picked up by Vandal, the primary source for this article.

It is no small admission. We are talking about Fortnite, one of the most played games on the planet and a pillar of the competitive scene; Unreal Editor for Fortnite (UEFN), the tool thousands of creators use to build their own maps; and Unreal Engine 6, the next major version of the engine that powers a large part of the industry. If AI is writing the bulk of all that, the debate stops being theoretical and starts directly affecting what we play and how it gets built.

What you need to know

• Epic admits it outright: its engineers no longer write most of the code, and the term Wassmer uses to describe it is vibe coding, programming by giving instructions to an AI.
• Three projects affected: Fortnite, Unreal Editor for Fortnite and Unreal Engine 6, which is to say the game, the creator platform and the in-house engine.
• Human oversight: according to the company, the AI generates the code but developers review and control the result.
• Epic's argument: develop faster and fix long-standing bugs that had been dragging on for some time.
• No hard numbers: the source gives no exact percentages or staffing data, so it is best not to speculate with figures.

What changes and who it affects

Until now, the official line from most major studios was that generative AI served as occasional help: autocompleting, suggesting snippets, speeding up repetitive tasks. What Epic is describing is a leap in scale. The working model Wassmer lays out flips the roles: the tool produces and the engineer directs, corrects and signs off. It is a very different way of understanding the craft from what was being taught just a few years ago.

The impact lands on three fronts. In Fortnite, players should notice it in the pace of updates and, if the promise holds, in the disappearance of bugs that have been a nuisance for seasons. In UEFN, map creators are working on a tool whose codebase is largely being written by AI, which could mean new features arriving faster, but also unexpected behavior. And in Unreal Engine 6, the effect reaches the entire industry, because hundreds of studios will build their games on that engine.

The precedent Epic is setting

Epic is not just any studio. When a company of its size publicly normalizes this approach, the rest of the sector takes note. Over the coming months we will likely see more companies acknowledging similar practices they had preferred to keep quiet until now, out of fear of the reaction from the community or from their own staff. Epic's bet on generative AI was already a strong one; this statement simply gives it a name and a scope.

Our take

Here at Underworld Lordz we see it with a mix of interest and distrust. As competitive players, the only thing we truly care about is that the game works: that the netcode responds, that the physics are consistent and that one patch does not break what the previous one fixed. If AI helps Fortnite arrive more stable every season, we welcome it. But stability in a competitive game is not measured by how fast code is written, but by the quality of the review, and that is where the line about human oversight sounds a little too convenient to us. Supervising thousands of machine-generated lines is not the same as understanding them.

For content creators on UEFN the matter is even more delicate. Many of them have built audiences and even income on that platform. They depend on the tool being predictable and well documented. An engine that evolves at full speed because AI makes it possible could leave behind those who do not have a team to help them adapt every week. Epic should pair this change with more transparency about which parts of the code have passed through human hands and which have not.

There is also a deeper question the industry cannot dodge: if the bulk of the code is already written by an AI, what happens to the next generation of game programmers? Learning to direct a machine is no substitute for knowing how to build from scratch. Epic may be buying time today at the cost of knowledge that nobody will have tomorrow.

What do you think?

This may be the inevitable future of development, or we may be looking at a rushed bet with a competitive game as its testing ground. Do you trust a Fortnite and an Unreal Engine written mostly by artificial intelligence, or do you think Epic's human team should stay at the wheel? Tell us in the team chat or on our Discord.