Riot Games Tech Blog
technology.riotgames.com · Company blog · on HN since 2019
Riot Games engineers write about the technology behind League of Legends and Valorant, including netcode, anti-cheat, servers, and testing.
What HN saysHN commenters recommend it as a good engineering blog at large scale and cite the Valorant netcode and fog-of-war anti-cheat posts.
89HN people shared it
50linked it in comments
58stories submitted
915story points
10 months agolast shared
2019people per year2026
Most-shared posts
- 1Demolishing Wallhacks with Valorant's Fog of War16 people · 6 points · first shared 2020 · discussion on HN
- 2A Taxonomy of Tech Debt (2018)11 people · 310 points · first shared 2020 · 75 comments on HN
- 3Automated Testing for League of Legends (2016)10 people · 3 points · first shared 2019 · discussion on HN
- 4Riot Games: Peeking into Valorant's Netcode (2020)8 people · 166 points · first shared 2020 · 87 comments on HN
- 5Supercharging Data Delivery: The New League Patcher7 people · 5 points · first shared 2019 · discussion on HN
- 6Valorant's 128-Tick Servers (2020)6 people · 231 points · first shared 2020 · 128 comments on HN
- 7Homepage6 people · first shared 2019
- 8Fixing the Internet for Real Time Applications4 people · 1 points · first shared 2019 · discussion on HN
- 9Fixing the Internet for Real Time Applications (2016)4 people · 1 points · first shared 2019 · discussion on HN
- 10Getting into the Guts of Berserk3 people · 18 points · first shared 2022 · 5 comments on HN
- 11Riot Games: Leveraging Golang for game development3 people · 6 points · first shared 2020 · discussion on HN
- 12Running Online Services at Riot: Part VI3 people · 6 points · first shared 2020 · discussion on HN
- 13The Future of League of Legend's Engine3 people · 3 points · first shared 2019 · discussion on HN
- 14Valorant Shaders and Gameplay Clarity3 people · 2 points · first shared 2020 · discussion on HN
- 15Strategies for Working in Uncertain Systems2 people · 5 points · first shared 2021 · discussion on HN
What HN people wrote when they linked it
cdiamand · 2021-11-16
The https://www.indiehackers.com/ forum probably has a lot of what you want, with small scale projects abound.
The riot games engineering blog is at a larger scale, but still awesome - https://technology.riotgames.com/
Is a pretty good read as well.
plucafs · 2025-08-10
I'd suggest to add the Riot Games tech blog (https://technology.riotgames.com)
dontlaugh · 2025-06-30
There are a few things you can do, for sure. The Valorant team has a good blog post on it (https://technology.riotgames.com/news/peeking-valorants-netcode). The Overwatch team did an excellent GDC talk on it a few years ago (https://www.gdcvault.com/play/1024001/-Overwatch-Gameplay-Architecture…
Behavioural analysis is indeed useful anyway, but I don't see anyone that has it giving up memory integrity anti-cheat.
Ultimately, I do think the game design makes it impossible to prevent cheating. It's unfortunate that it's precisely this design that many enjoy.
shaokind · 2025-04-04
This is a really old idea. It was implemented in CS:GO in ~2015 [0], although community anti-cheats like SMAC have implemented it for years before then [1]. Riot have an article about their implementation of the same idea in VALORANT's that a good read from a technical perspective [2].
Sadly, CS2, from what I've gathered, broke this.
[0]: https://www.reddit.com/r/GlobalOffensive/comments/35zwwy/optional_coun…
[1]: https://www.youtube.com/watch?v=qkhQgYB4lAA
[2]: https://technology.riotgames.com/news/demolishing-wallhacks-valorants-…
Jasper_ · 2022-09-11
Riot Games also has an automated testing framework: https://technology.riotgames.com/news/automated-testing-league-legends
I still think the best combo is a mix of automated and QA. Software in general went through a large decline in quality after QA was laid off across the industry, and in my experience, automated testing just tends to find different kinds of issues. Also, playtesting is also not the same thing as QA, but I digress :)
pizza234 · 2022-07-27
Although generally less technical, Riot Games' tech blog is well done: https://technology.riotgames.com.
jwitthuhn · 2022-07-27
Great content, I loved their post covering the valorant netcode here: https://technology.riotgames.com/news/peeking-valorants-netcode
idunno246 · 2022-07-20
i think riot put together a good article on technical debt: https://technology.riotgames.com/news/taxonomy-tech-debt
i stopped using the term technical debt. 'technical debt', 'refactoring', etc are not helpful to product owners. if something is contained in an area youre never touching, its not really worth even tracking because making it better won't improve any business metrics. tickets get lost, better to throw a comment in the code if anyone starts touching it later. If new functionality requires code changes, then that's just part of the requirements for that functionality. If some bit of code is slowing you down, then its a first class ticket to speed up developers, with explicit numbers on hours saved.
at the end of the day, the business doesn't care about code quality, it cares about revenue/profit, so reframe any tech debt in those terms
jsnell · 2021-08-28
Though there are games where the fun has been proven, and it's important to be able to iterate fast without breaking what's already there. There's a great 2016 blog post from Riot on how they test LoL:
https://technology.riotgames.com/news/automated-testing-league-legends
zubspace · 2019-09-13
How useful is this test tool to you? What bugs did you find or do you hope to find this way? How often and long do you run it?
I'm asking, because I guess, it probably takes ages to traverse some kind of dungeon. If there are special sequences, the tool will most likely never find them (like find key, open door, kill boss), right?
I've done some small games in my spare time, but Unit-Testing was either completely useless or way overkill. But I guess, the larger your game gets, the more important it will be.
But the the work involved is so huge, that I think it's not worth it for indy games or small studios. If you look at the test setup for AAA-Games, like League of Legends [1], the work involved is mind-blowing...
[1] https://technology.riotgames.com/news/automated-testing-league-legends
efokschaner · 2019-09-08
Not FPS specifically, but you might enjoy Riot Games' tech blog https://technology.riotgames.com/ which has articles on a variety of game technology things such as service deployment, network infrastructure, game performance monitoring etc.
(Disclosure: I work there)
sovietmudkipz · 2025-12-19
Hmmm makes sense. Sounds like I may have a misunderstood mental model of resource consumption. I ought to reread https://technology.riotgames.com/news/valorants-128-tick-servers (specifically the section on “Real World Performance” where the engineer describes tuning) now that I have a better appreciation that they’re not trying to make resource utilization % higher, but instead making available more resources through tuning efforts.
wavemode · 2025-12-01
Many forms of cheating revolve around modding the game locally so that certain textures can be seen through walls, so you always know where opponents are. So you aren't breaking any laws of physics, you are just able to make much better tactical decisions.
The obvious solution would be, just don't send data to the player's client about enemies that are behind walls. But this is a surprisingly hard thing to engineer in realtime games without breaking the player experience (see: https://technology.riotgames.com/news/demolishing-wallhacks-valorants-… and then notice that even in the final video wallhacks are still possible, they're just more delayed).
ThatPlayer · 2025-11-03
Riot has a pretty good article about why it is hard: https://technology.riotgames.com/news/demolishing-wallhacks-valorants-… . Anything more than simple geometry makes server side calculations costly, especially when you're targeting 128 tick/s.
Their settled solution is still not perfect, hence still the need for client-side anti-cheat. The final video clip is definitely done to look effective than it actually is. Those positions are transmitted based on space, not time, and in a real game you'd be moving slower.
Mobas generally have a lower tickrate and simpler vision setups
wyldberry · 2025-10-06
Good thing they thought of that. Disclaimer: I was at Riot During some of the Valorant dev cycle and the stated goal in this tech blog [0] was a huge goal (keeping latency < 35ms).
This was only really doable because Riot has invested significantly in buying dark fiber and peering at major locations worldwide [1][2]
[0] - https://technology.riotgames.com/news/peeking-valorants-netcode [1] - https://technology.riotgames.com/news/fixing-internet-real-time-applic… [2] - https://technology.riotgames.com/news/fixing-internet-real-time-applic…
skocznymroczny · 2025-08-24
League of Legends does a lot of automated testing for their gameplay logic https://technology.riotgames.com/news/automated-testing-league-legends
recursivecaveat · 2025-08-23
This is already done in Valorant at least (and presumably other games I'm not as familiar with). Unfortunately you are strongly limited by network latency. Imagine you're standing up against a wall next to a door. You expect if you step 1 foot sideways to instantly see the entire room and everyone within it. Hence your client already has to know everyone's locations in the room or you will get pop-in. You can limit people's ability to get truly implausible free information, but pretty much any-time someone is rounding a corner there is an unavoidable period of game-breaking free information you have to give the client.
If you look at the bottom gif in this post you can see what a huge advantage a wall-hack still is: https://technology.riotgames.com/news/demolishing-wallhacks-valorants-…
pbronez · 2025-08-10
Cool idea. I thought I’d try to make a Kagi Lens to accomplish the same thing:
https://kagi.com/lenses/LdYine8hZtYmrt8yTMngOUtvTM9rmkRy
Kagi Lenses can be defined in many ways, one of which is specifying URLs to search. Unfortunately you can only provide 10 URLs per lens. Here are the ones I chose:
https://stripe.com/blog/engineering, https://engineering.fb.com/, https://www.uber.com/en-US/blog/engineering/, https://netflixtechblog.com/, https://research.google/blog/, https://technology.riotgames.com/, https://incident.io/blog, https://www.anthropic.com/engineering, https://openai.com/news/, https://shopify.engineering/
enragedcacti · 2024-10-30
Spot on: "We have cast shadows only on objects in first person, like your own hands and weapon. This is to avoid cast shadows being a competitive factor in both effect (knowing where your cast shadow is) and performance (low-spec machines can’t reasonably run well with cast shadows)."
https://technology.riotgames.com/news/valorant-shaders-and-gameplay-cl…
jsheard · 2024-10-24
A related article on refining their netcode to minimise the usefulness of wallhacks:
https://technology.riotgames.com/news/demolishing-wallhacks-valorants-…
Not many first person games have that "fog of war", it turns out to be quite hard to implement well.
oxidant · 2024-10-13
This article[0] about tech debt was posted the other day on HN. It seems to be a good guide for how to determine what type of tech debt to take on.
Exactly what you're saying - does this tech debt Work™ or is it affecting future development or causing incidents?
[0] https://technology.riotgames.com/news/taxonomy-tech-debt
rakoo · 2024-02-14
As of 2015, League of Legends' chat is xmpp (https://technology.riotgames.com/news/chat-service-architecture-protoc…
billywhizz · 2024-02-11
this might be it? https://qz.com/790208/how-the-company-behind-league-of-legends-rebuilt…
also, linked from that: https://technology.riotgames.com/news/fixing-internet-real-time-applic…
Mawr · 2023-10-15
Check out these in-depth articles from the Valorant devs:
- https://technology.riotgames.com/news/demolishing-wallhacks-valorants-…
- https://technology.riotgames.com/news/peeking-valorants-netcode
knagy · 2023-03-27
Reminds me of this article from Riot Games about how they deliver patches:
https://technology.riotgames.com/news/supercharging-data-delivery-new-…
ativzzz · 2022-09-17
Old post so IDK if they still do it, but Riot Games does some automated testing for League of Legends: https://technology.riotgames.com/news/automated-testing-league-legends
Operyl · 2022-09-12
> The only big-budget one I know of that has publicly put a large effort into it is Sea of Thieves.
Another big big title that makes use of automated testing is Riot’s League of Legends.
https://technology.riotgames.com/news/automated-testing-league-legends
trinovantes · 2022-04-30
If this catches on, web developers may start employing memory obscurification techniques like game developers
https://technology.riotgames.com/news/riots-approach-anti-cheat