What game engine does Apex Legends use?

Apex Legends is developed using the Source engine. This game engine, originally created by Valve Corporation for their game Half-Life 2, has been modified and adapted extensively by Respawn Entertainment to handle the advanced mechanics of Apex Legends. The Source engine in Apex Legends supports the game’s fast-paced movement, detailed environments, and intricate character abilities while maintaining high performance across various platforms, allowing for a seamless battle royale experience that can sustain large numbers of players simultaneously on expansive maps.