Epic Games is using AI to develop Unreal Engine code and features, and an executive says the tools have fixed bugs the company had pursued for a decade, Game Developer reported on 28 October. Marcus Wassmer, Epic’s executive vice-president of development, described the work after the company outlined its AI plans at Unreal Fest in Chicago. The tools are being applied to the software Epic builds, rather than only to games made with it.
Key points
- Wassmer says AI-assisted development is concentrated in work connected to Fortnite, Unreal Editor for Fortnite and Unreal Engine 6.
- He says tools including Claude and Codex have resolved bugs Epic had worked on for a decade.
- Epic says engineers control the scope of AI use, although they are not writing most of the code in the process Wassmer described.
Wassmer places AI in Unreal Engine development
Unreal Engine is Epic’s game-development platform, used by studios beyond the company. Wassmer said AI-assisted work is taking place principally in development streams associated with Fortnite, Unreal Editor for Fortnite, known as UEFN, and Unreal Engine 6. Those streams put the tools inside Epic’s work on its own games and development software.
Wassmer also raised the possibility of an Unreal Engine 5.9 release. If Epic makes that version, he said, it would be a relatively modest update to particular systems and would contain AI-developed changes. He described UEFN and Unreal Engine 6 as the company’s main development priorities.
Tools including Claude and Codex have eliminated bugs in Unreal Engine that Epic had spent a decade trying to resolve, Wassmer said. He described the problems as “non-deterministic cooking bugs”, involving the preparation of game content. The decade-long effort gives a measure of the engineering problem Epic says the tools have addressed. Wassmer also said they help the team maintain stability while it updates and simplifies the engine’s older code.
Fortnite monitoring and engineers’ control
Wassmer said Epic uses AI tools to monitor Fortnite’s stability on PCs. The monitoring alerts the company to combinations of drivers and hardware associated with problems, he said, reducing the manual work involved in finding them. That use concerns an operating game, alongside the company’s use of AI to write and change development software.
Engineers are not writing the bulk of the code in the AI-assisted process Wassmer described, but they control the scope of the tools’ use, he said. His account puts decisions about where AI is applied with Epic’s engineering staff even as the tools produce much of that code. Wassmer said the company was more concerned about moving too slowly than about scepticism towards AI.
Wassmer expects AI-assisted development to become common across software. He said Epic would address scepticism through the quality of the games and tools it delivers. Those are expectations about future work, distinct from his account of the engine bugs resolved and the Fortnite monitoring already in use.
Epic extends its AI pivot beyond Fortnite
Epic has also said it rebuilt its game launcher through “vibe coding” and that the rebuilt software runs notably faster. The launcher gives the company another example, beyond Unreal Engine and Fortnite, of its stated use of AI in its own products. Epic has indicated that it plans to change Unreal Engine’s licence terms to permit AI training on output from the software.
The engine work follows a broader change in direction announced by chief executive Tim Sweeney. An earlier AI Affairs report on Epic’s Disney game project covered the project’s delay and the company’s direction to developers to use AI tools. Wassmer’s account describes how that approach is being applied to Epic’s development platform itself.
Sweeney said Epic was moving developers between teams to prepare for greater AI use. He described the aim as enabling employees to build more, rather than producing the same amount of work with a smaller workforce. Wassmer, meanwhile, said Epic’s engineers continue to determine the scope of AI use in the code-development work he described.
