Science & Tech · AI · 16 hrs ago
Epic details AI use in Unreal Engine and Fortnite development
Epic Games is using AI tools to help write code for Unreal Engine, Fortnite and related software.
The company says its engineers guide the tools and refine their output rather than relying on a single prompt to build a finished product.
Epic named Claude Code and Codex among the tools it uses.
It says AI helped reduce long-running game-building bugs, shrink shader-related patch sizes and rewrite part of its D3D12 rendering layer in about one week, rather than an estimated three to six weeks for one engineer.
Epic says AI has also helped Fortnite teams monitor PC stability and fix problems faster.
The company says it is more concerned about falling behind by moving too slowly than about skepticism over AI.
Epic plans to keep using AI in development, including work on Unreal Engine 6, while aiming to deliver tools and games that meet its performance and quality standards.
Epic Games is using AI tools to help develop Unreal Engine, Fortnite and other software.
Executive vice-president of development Marcus Wassmer said engineers guide AI tools to produce code and achieve desired designs.
The tools include Claude Code and Codex, and Epic says they have helped fix bugs, reduce patch sizes and speed up engineering work.
Wassmer said AI-assisted development is happening across work on Fortnite, Unreal Editor for Fortnite and Unreal Engine 6.
He said Epic is more concerned about moving too slowly than about skepticism toward AI.
- Who
- Epic Games, including development teams overseen by executive vice-president Marcus Wassmer.
- What
- The company is using AI tools to help write and analyze code and develop features.
- When
- Epic described its current use of AI in statements reported on October 28, 2026.
- Where
- Across Epic’s backend, engine and game development teams, including work on Fortnite and Unreal Engine 6.
- Why
- Wassmer said the tools can speed up development and that Epic is more concerned about moving too slowly than about AI skepticism.
This story does not have two clearly opposing sides.
Wassmer wrote in an Unreal Engine 6 blog post that Epic had opened broad use of code generation and AI analysis across its engineering teams.
Tim Sweeney criticized Steam’s AI disclosure statements, comparing them to mandatory political essays.
Articles reported Wassmer’s further details on Epic’s use of AI tools in development.
- AI tools
- Claude Code and Codex
- Shader work
- AI-assisted compression work helped reduce patch sizes
- D3D12 rendering layer
- A rewrite estimated at three to six weeks for one engineer was completed in about one week
- Development areas
- Fortnite, Unreal Editor for Fortnite and Unreal Engine 6
- Bug monitoring
- Fortnite has automatic PC stability monitoring, root-cause analysis and fix generation
3 sources
Epic Games further doubles down on gen-AI tools for Fortnite, Unreal Engine 6 and more: "Our engineers are no longer writing the bulk of the code"
"We are more concerned about the risks of moving too slowly": Epic get more specific about genAI use in Unreal Engine and Fortnite development
'Yes, we are vibe-coding things': Epic confirms it's using AI tools to code Unreal Engine 6, Fortnite, and more
What people are saying
We are more concerned about the risks of moving too slowly than we are about AI skepticism.
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.
The best way to counter any [AI] skepticism is through the quality of the games and tools we’re able to deliver.