Determinism in League of Legends: Implementation

Taking the League of Legends game server from a nondeterministic process to its current state required almost a full year of effort from multiple engineers. As a side benefit of this effort, we holistically improved the codebase’s robustness, discoverability, and maintainability. We removed swaths of dead or redundant code and created new opportunity spaces for gameplay exploration.

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Posted by Rick Hoskinson

Determinism in League of Legends: Introduction

Hi, I’m Rick Hoskinson, an engineer on the Deterministic Disaster Recovery team, and I’m here to talk about how we gave ourselves the power to turn back the hands of time in League of Legends. In this series of blog posts, I hope to give you a glimpse of what that work looked like, juicy technical challenges and all. In this first post, I’ll introduce the problem and how we chose to solve it. 

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Posted by Rick Hoskinson

Blitzcrank Bot

Hey everyone, my name is Michael Hill and I’d like to introduce you to Riot’s automated ticket agent, Blitzcrank Bot.

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Posted by Michael Hill

Better Living Through Materials

Hi, I’m Paul Geerts and I’m one of the engineers on League’s Render Strike Team. A while back my buddy Tony posted an article about how League of Legends currently builds a single frame of the action. Today, I’d like to dive into a component of the rendering pipeline that we’re actively improving: materials. I’ll discuss some of the changes we’ve made and why they’re important for players and developers alike.

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Posted by Paul Geerts

Running Online Services at Riot: Part III: Part Deux

In our previous article, we discussed some of the networking involved in rCluster, Riot’s solution for worldwide application deployments. Specifically, we talked about the concept of overlay networks, an implementation we leverage called OpenContrail, and how that solution plays with Docker. In this post, we’ll build on that foundation and dive deeper on other topics: infrastructure as code, load balancing, and failover testing.

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Posted by Doug Lardo and David Press

Debugging Titles: Part III

In my last two articles, I introduced Masteries - our framework for clarifying career progression within Riot Engineering. I covered the design of the system and how we arrived at version 1.0. In this article, I’ll discuss the rollout, lessons learned, and our plans for the future of Masteries.

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Posted by Mike Seavers

Riot Messaging Service

Hey there! My name is Michal 0xDEADB33F Ptaszek, and I’m a software architect at Riot. Today I would like to talk about communication. But not the kind of communication you’re probably thinking of. I want to talk about the other, more exciting kind of communication: LoL players communicating with chat servers during a tense game; authentication servers communicating with the LoL client on login; microservices that route state changes between clients in the middle of the night - you know, that kind of communication.   

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Posted by Michal Ptaszek

Under the hood of the League Client’s Hextech UI

Hi! I’m Jules Glegg, a Software Architect working on the League client update. We’ve been fielding a lot of questions about how the updated client’s Javascript/HTML/CSS works, and there’s a huge amount to cover there. I’m here to give a very broad overview of the most interesting parts of our UI architecture - we won’t get to cover every bolt and weld in this post alone, but we should get a good feel for the general shape of things.

If you see something you want to know more about, drop a comment and let us know! For now though, let’s dive in.

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Posted by Jules Glegg


A Trip Down The LoL Graphics Pipeline

Hi, I’m Tony Albrecht and I’m one of the engineers on the new Render Strike Team under the Sustainability Initiative in League of Legends. The team has been tasked with making improvements to the League rendering engine, and we’re excited to get our hands dirty. In this article, I’ll provide a run-down on how the engine currently works - hopefully this will be the foundation on top of which I can later discuss the changes we make.

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Posted by Tony Albrecht