Riot Games gave a talk at Unreal Fest 2024 titled "Riot's Multi-Game Unreal-Based Development Ecosystem". Nine months later, on 29 July 2025, Valorant moved from Unreal Engine 4 to Unreal Engine 5 with patch 11.02. The MMO is confirmed to run on Unreal. Which Unreal, Riot has never said, and those two facts are the whole of the evidence.
That evidence is good, and it is still evidence rather than confirmation. This article sets out what is known, what is inferred, and what the choice does to the game.
What is confirmed
Unreal Engine. That is the one fact about the MMO's technology that has been stated, and it appears in the game's Wikipedia entry as a confirmed detail rather than a report.
Nothing else. Not the version, not the server architecture, not the target hardware. Riot's silence since the 2024 reset covers technology as thoroughly as it covers design.
Why Unreal Engine 5 is the inference
Riot runs three engines. League of Legends and Teamfight Tactics run on the company's own in-house engine, built for one game in 2009 and stretched ever since. Legends of Runeterra and Wild Rift were built on Unity, as TweakTown reported when the company's smaller games began appearing. Valorant was built on Unreal Engine 4 and is now on Unreal Engine 5; 2XKO is on Unreal as well.
The Unreal Fest talk described a shared, Unreal-based development stack that serves several Riot games at once: common tools, common pipelines, one engine team supporting many projects. A studio that has built that does not start its largest new project on the previous major version. And Valorant's migration, a live competitive shooter with a low tolerance for disruption moved to Unreal Engine 5 in the middle of its life, tells you the company had already decided the newer engine was stable enough for anything it makes.
So: Unreal Engine 5, almost certainly. Riot has not said so, and until it does, that sentence ends with "almost".
What the choice means
Three consequences, in order of confidence.
The world can be large. Unreal Engine 5's World Partition system exists to stream open worlds without the loading screens that carved older MMOs into zones, and its lighting and geometry systems, Lumen and Nanite, are built for exactly the dense, hand-painted environments Runeterra's art demands. Greg Street's 2021 promise of a "very large" world is, on this engine, an ordinary ambition rather than a special one.
The servers are Riot's problem, not Epic's. Unreal is a client and rendering engine with networking designed for matches of dozens, not worlds of thousands. Every MMO built on it, from the Lineage series onward, has written its own server layer, and Riot will be no exception. This is where the company's own experience is deepest, having run League's infrastructure across the world for fifteen years, and it is also why the first World of Warcraft veteran Riot hired for the project, in 2024, was an engineering manager rather than a designer. The list of who came when is in the WoW all-star team.
Consoles are possible. Unreal Engine 5 ships to PlayStation and Xbox as a matter of course, and a Riot game on the engine has no technical reason to stay on PC. Riot has announced nothing about platforms, and its record is mixed: Valorant reached consoles in 2024, four years after PC, and League never has. The engine removes an obstacle; it does not make a decision.
What it costs
Unreal MMOs have a reputation, and not all of it is fair. The engine's defaults favour visual density over the performance of a hundred players in one place, and the games that fought that battle badly, at launch, are remembered for it. The ones that fought it well are simply remembered as games. Riot's advantage is time: it has had the engine, the shared stack and a dedicated engine team since before the reset, and the reset itself bought two more years of technical foundation before anyone outside the company sees a frame.
The other cost is the minimum specification. A Runeterra MMO built to show off Lumen and Nanite would exclude the machines that run League, and League's audience is the MMO's whole commercial case. Riot has solved this before: Valorant runs on very modest hardware by design, on the same engine. We expect the MMO to follow that rule rather than the settings Epic uses for its demonstrations, and we say so as an expectation, not a fact.
What we do not know
The version, formally.
Whether the MMO shares its server technology with any other Riot game, or with Project T, the company's other unannounced online project, described in Project T, Riot's other MMO.
Whether the reset changed any of this. The engine was not the problem Marc Merrill described in March 2024, so it presumably carried over; "presumably" is the most anyone outside Riot can say. The reset itself is in the 2024 reset, explained.
The target hardware, and therefore the platforms. Both are on the list of unknowns in everything we actually know about the Riot MMO, and both will be answered by the first trailer, whenever it comes.