The announcement from Unity only mentions the digital card game Legends of Runeterra and League-for-mobile reimagining League of Legends: Wild Rift as Unity-powered projects.
Unity Technologies made note of the development in a press release, announcing that Riot Games’ Legends of Runeterra and League of Legends: Wild Rift are both built using Unity.
There’s no mention if Riot is using an in-house engine, Unity, or another option for the unnamed first-person shooter, RPG, and fighting game projects also currently being developed at the studio.
Riot Games built the engine powering its flagship game League of Legends from scratch, but a pair of upcoming games in development are taking a different route and making use of Unity.