Epic Games tests 'On-the-Fly' LLMs for dynamic NPC dialogue in Unreal Engine

Gaming · 4 min read

Epic’s On-the-Fly system hooks curated LLMs into the engine’s AI pipeline, allowing NPCs to react in real time to player actions and environmental triggers. The system supports context windows that include recent player interactions, quest state and world variables to keep dialogue coherent.

Developers can author personality profiles and safety filters, and Epic provides moderation tools to prevent inappropriate content. There's also an offline mode where smaller, distilled models run locally for console builds or sensitive deployments.

The feature is currently in closed beta with select studios and will expand to Unreal Engine Marketplace partners. Epic emphasized that creative control remains in developers’ hands: narrative designers can predefine dialog arcs and selectively allow generative variations where appropriate.