League of Legends has dominated the gaming world for more than a decade, but many fans and developers alike still wonder what makes it tick behind the scenes. With its fast-paced gameplay, complex mechanics, and massive multiplayer infrastructure, Riot Games’ flagship title is a technical marvel. So, what programming language is League of Legends actually written in?
The answer isn’t just one language—it’s a sophisticated blend of several, with C++ serving as the foundation.
The Core: C++
At the heart of League of Legends lies C++, one of the most widely used languages in high-performance game development. Riot Games chose C++ for its:
- Speed and performance – Critical for real-time processing in a game where milliseconds matter.
- Memory control – Allows developers to fine-tune how resources are used, ensuring smooth gameplay across a wide range of PCs.
- Established game dev libraries – Such as DirectX and custom physics engines.
Most of the game’s logic, engine architecture, and networking code are believed to be written in C++, especially components involving gameplay mechanics, champion abilities, and AI behavior.
Featured League of Legends accounts
on North America
One Free skin included with
every account
Supporting Languages and Technologies
Like many modern games, League of Legends isn’t powered by a single language alone. A variety of tools and systems are used to support development, content creation, and game operations.
Lua (Scripting Language)
- Riot has used Lua, a lightweight scripting language, for aspects of game scripting and modifiability.
- Lua is often used to implement champion abilities, particle effects, and other game behaviors that need to be quickly tested and adjusted by designers.
Python
- Widely used at Riot for tools development, automation, and internal testing.
- Python scripts help with building content pipelines, validating patches, and streamlining developer workflows.
JavaScript and Web Technologies
- Riot’s client interface (the launcher and lobby system) and out-of-game services involve JavaScript, HTML/CSS, and React.
- The frontend for patch notes, matchmaking queues, and shop interfaces are all built with web technologies.
C# and Unity (Spin-offs and Tools)
- Some of Riot’s tools and newer games—like Legends of Runeterra—are built using C# and the Unity engine.
- In the main League ecosystem, C# is used for internal tools and UI features.
Game Engine: Riot’s Proprietary Tech
Unlike many studios that rely on commercial engines like Unreal or Unity, Riot Games developed a proprietary engine specifically for League of Legends. This custom engine has been updated and expanded over the years but continues to run core gameplay elements using C++ at its base.
This choice allows Riot to maintain full control over performance, patching, and scalability—especially important given the game’s global presence and massive player base.
Server-Side Tech
On the server side, Riot has historically relied on a combination of C++, Java, and other backend languages to manage matchmaking, player data, and real-time communication between clients.
Their infrastructure also includes:
- Custom server logic to handle game sessions.
- Database systems for player profiles, match histories, and loot.
- Cloud-based tech stacks for deployment, especially as Riot has moved toward containerized services.
Final Thoughts
So, what programming language is League of Legends written in? While C++ forms the backbone of the game, Riot leverages a full suite of languages—Lua, Python, JavaScript, and C#—to support everything from gameplay scripting to server management and tool creation.
This multi-language ecosystem reflects the complexity of modern game development—and shows how Riot’s technical decisions have enabled League to remain one of the most popular, scalable, and finely-tuned games in the world.
Written by:
Christian