Which game engine did Fortnite move to with Chapter 3 in December 2021?

Fortnite moved to Unreal Engine 5 with Chapter 3 in December 2021.

The transition coincided with the launch of Fortnite Battle Royale Chapter 3, Season 1, which began on December 5, 2021. Epic used Fortnite as a major testbed for Unreal Engine 5, allowing the studio to deploy new rendering and streaming technology in one of the world’s most-played games.

Unreal Engine 5 was not a completely new game or a separate Fortnite edition. It was the underlying engine technology powering the live game, with the change supporting ongoing visual, lighting, geometry and world-streaming improvements. Epic later highlighted features such as Nanite virtualized geometry and Lumen global illumination in Fortnite, especially on newer hardware.

Players sometimes confuse the engine change with Fortnite’s later Chapter 4 upgrade to Unreal Engine 5.1. Chapter 3 marked the initial move from the Unreal Engine 4 generation to Unreal Engine 5; subsequent engine versions brought additional improvements.