With this resource, I hope to gain and share an in-depth understanding of Roblox’s Discovery system. This all in the hopes to better understand what I’m truly advocating for when I ask for ‘better discovery’. It is best to know what already is before asking for change.
All info gathered here is from Roblox, with my interpretation if not quoted. I recommend checking out root sources if you wish to learn more, the links are in the “Works Cited” section of this post. Sources are referred to by a number corresponding to their place in the Works Cited list.
Combined info - What goes into it the Main Algorithm?
- “Experience Content” (14):
- Engagement
- Long-term retention
- Monetization
- Safety
- Does it violate Roblox TOS?
- What are the Experience Guidelines Age Rating?
- Recency
- How long ago was the game updated and/or published?
- Popularity (14)
- “Performance” (14)
- I assume this means crash ratings and maybe error reports.
- Personalization factors:
- User account Info (14)
- Friends (“connections” 14)
- What are they interacting with/playing?
- Demographic of user (Age, gender, location)
- Device of user (Mobile, Console, PC, VR, etc.)
- Other experiences the user has engaged with and ignored (“activities” 14)
- Robux the user spent on the experience
- I assume, if someone spends money, show them the same/similar games more.
- Time the user has spent in the experience
- I assume, if someone plays a lot, show them the same/similar games more.
- Friends (“connections” 14)
- User account Info (14)
- Other:
- “How well does the experience retain their audience?”
- The “their” here could mean the experience’s audience in general. Or, an audience similar to the end user. (demographics, device, etc.)
- “How well does the experience retain their audience?”
From Roblox's Documentation on Discovery (Sources: 1-2)
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Core principles that guide investments in discovery:
- Value - Discovery distribution is primarily based on value. Value is demonstrated through engagement, long-term retention, and monetization, as well as safety.
- Personalization - ensures everyone can find unique content that is relevant to their interests.
- How is what someone finds “interesting” determined? Can’t say for sure with this source alone.
- Safety - Roblox won’t recommend and will remove policy-violating experiences.
- Takeaway: Follow Roblox TOS
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“The Home page is where a majority of discovery takes place and consists of recommendations which are algorithmically generated to optimize for engagement, long term retention and monetization.”
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Factors and signals are taken into account when generating recommendations for someone, for example:
- What is their demographic (age, gender, location)?
- What device are they using Roblox on?
- What content have they engaged with before and what have they ignored?
- How often do they return to something they have engaged with before?
- How much time or Robux have they invested in the experience?
- How well does the experience retain their audience?
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‘majority of discovery happens on the Home page’
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Use keywords in the Title, Description, metadata of images, etc.
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“When publishing a new experience, it can take multiple days to appear in content discovery.”(2)
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“When updating your experience’s metadata, it may take up to 14 days for your experience to repopulate in discovery pages and search results.”(2)
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“If your experience has recently been moderated, ensure that you completely revert your title and description to restore visibility on the discovery systems.”(2)
Info from the "Growth Engineering - Roblox Tech Talks" (Source: 4)
- ‘have to not only recommend things but also need to find the “next best option”.’
- There is nuance in discovery. Look at similar games to what you are making and learn from them. See what your friends are playing.
- It’s challenging to recommend experiences in an egalitarian way. It’s important to be fair and transparent. The algorithm does not have a manual intervention, it’s a neural network that evaluates new signals. Doors is an example, a game that grew from understanding the audience.
- Discovery is a push. Search is explicitly saying what you want. The search engine’s job is to help you.
- Roblox has a push in Semantic Search with machine learning to try to understand user intent. Anupam Singh really has this vision of assuming player intent with one search bar.
- They are saying that it’s challenging to filter through every game on Roblox. To make sure everything is correct in things, all that data needs to be filtered. But, the queries are far too expensive that it just wouldn’t work. There are hundreds of millions of experiences on Roblox. Machine learning and AI is here to help with that issue of there being too much.
- It’s difficult to build a discovery system for 5 years out. Break it up into pieces. Find similar users, which can be nuanced. Then, find every game/experience that is similar. Then, the activity of friends.
- “V1 of discovery at Roblox, when we launched, one home page showing which experience on Roblox had the most people in it in real-time, and showing them biggest to smallest. And that was called our popular sort.” - David
Info about Game Sorts (Sources: 5-13)
Featured Sort/s (5):
- At one point, Roblox was publicly updating this sort in many ways. There was the Xbox Featured sort and theme-related sorts (spring, summer, halloween, Winter & Happy New Year).
- The Xbox Featured sort, and it’s guidelines, are no longer public/available due to PlayStation release.
- This system had it’s own requirements, but it’s hard to tell if that system is till prevalent today. The Featured sort exists right now, but I think it’s a different kind of “featured”: https://www.roblox.com/discover#/sortName/Featured
Popular Sort/s (6)
As of writing this, Jan 6th 2024, there are many ‘Popular’ sorts:
- Popular Worldwide → https://www.roblox.com/discover#/sortName/Popular
- Popular → https://www.roblox.com/discover#/sortName/PopularInCountry
- There used to be a sort called “Popular Near You” as shown in a screenshot here: https://devforum.roblox.com/t/changes-to-the-popular-sort/210816/18. I assume that sort is the now “PopularInCountry” sort.
- Popular Amoung Premium → https://www.roblox.com/discover#/sortName/Curated_94
- Unsure if this is for all of Roblox or by country. I assume it is by location of relevancy info Roblox uses in the wider algorithm
- People Love → https://www.roblox.com/discover#/sortName/Curated_81
- This is kinda a ‘popular sort’. I assume it to be based on like ratings, but it could very well be driven by multiple factors like playtime.
I assume the following quote to be speaking of the ‘Popular Worldwide’ sort:
Roblox Asking for Sort Ideas (7)
Key Quotes:
My Notes:
The thing about all this is that we as a community have come to the conclusion that we don’t necessarily want more sorts by Roblox. We want tags we can add to our games. That is a much better solution and has been requested multiple times: Multiple Genres + More Genres - #3 by PeZsmistic
Free Private Server Sort (9-10)
Status of Sort: Closed, cannot apply.
Key quotes:
My Notes:
I personally don’t think a requirement of the sort should’ve been needing “an element similar from what you would do in day-to-day outdoor life”. That doesn’t lend to the best UX of the sort name. It’s called “Free Private Servers”, not “IRL Simulators that have Free Private Servers”.
The sort seem to exist anymore, mention of it is nowhere but this forum from what I’ve found. The name also used to be “Play Together (10 Robux VIP Servers)”, having it be free was a great change to match that vision of connection.
Other:
- There used to be an Rthro sort for games that used Rthro: Is Rthro tag required on the game logo if your game is in the Rthro sort? - #10 by InceptionTime.
- This used to be a thing for a bit: One World: Together At Home Game Sort. There used to be an Events sidebar from what I recall, quite interesting to see events on Roblox and here they go.
Info from "Recommendations and Ranking on Roblox" (Source: 14)
“When presenting search results for Experiences, we consider User’s account information, activities, relevance to the search and Experience content, quality, performance, and popularity. Overall popularity indicates there is a high chance other Users will like the experience. When recommending Experiences, we consider User’s account information, activities, and connections, as well as Experience content, quality, performance, and popularity. User’s activity indicates certain interests, and based on the popularity, there is a very high chance that User will like the experience as well.”
Info from an AMA on 1/24/2024 by Roblox Staff (Source: 15)
Works Cited:
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Roblox. “Designing for Roblox | Documentation - Roblox Creator Hub.” Roblox Docs, Designing for Roblox | Documentation - Roblox Creator Hub.
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Roblox. “Discovery | Documentation - Roblox Creator Hub.” Roblox Docs, Discovery | Documentation - Roblox Creator Hub.
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Roblox. “Driving Discovery on Roblox | RDC 2021.” YouTube, 1 December 2021, https://www.youtube.com/watch?v=DHvfEB8myyU.
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Roblox. “Growth Engineering - Roblox Tech Talks | Podcast on Spotify.” Spotify, 5 June 2023, Growth Engineering - Roblox Tech Talks | Podcast on Spotify.
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KnightGaladeld (Roblox Staff). “CTA: Themed Featured Game Sorts”. Roblox Devforum, Posted Aug 10th 2018, Last edited Jan 28th 2020. CTA: Themed Featured Game Sorts.
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new_storm (Roblox Staff). “Changes to the Popular Sort”. Roblox Devforum, Posted Dec 13 2018. Changes to the Popular Sort.
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KnightGaladeld (Roblox Staff). “Upcoming Changes To The Game Sorts & Submit New Sort Ideas!”. Posted May 3rd 2019, Last Edited March 11 2019. Upcoming Changes To The Game Sorts & Submit New Sort Ideas!.
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budgetFox (Roblox Staff). “New Changes to the Learn & Explore Sort”. Posted Sep 28 2021, Last Edited Oct 12 2021. New Changes to the Learn & Explore Sort.
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InceptionTime (Roblox Staff). “Introducing the Free Private Servers Sort”. Posted Apr 3 2020, Last Edited Feb 7 2022. Introducing the Free Private Servers Sort.
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Kairomatic (Roblox Staff). “Free Private Servers and Game Sorts Updates!”. Posted Jul 1 2020. Free Private Servers and Game Sorts Updates!.
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Kairomatic (Roblox Staff). “New Game Sort: ‘Recommended For You’”. Posted Jul 1 2020. New Game Sort: "Recommended For You".
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koaffle (Roblox Staff). “Improvements to Game Search Ranking”. Posted Jul 15 2020. Improvements to Game Search Ranking.
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auggadoodle (Roblox Staff). “We’ve Rebuilt Sponsored Games!”. Posted Oct 22 2020, Last Edited Jan 13 2021. We’ve Rebuilt Sponsored Games!.
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Roblox Legal Team. “Recommendations and Ranking on Roblox”. Accessed 1/16/2024. https://en.help.roblox.com/hc/en-us/articles/21416941036564.
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Aelarix (Roblox staff). Response in AMA about discovery. Accessed 1/25/2024. Creator Roadmap - AMA with Dan and Manuel [Jan 24, 2024] - #243.
There’s a lot to understand about the Algorithm & Discovery on Roblox. I’ll be adding more to this when I have the time. I’ll reiterate that to change things for the better, we need to understand what is, what was, and Roblox as a company. And, I hope this community resource does that to an extent.
Thanks to all the Roblox Staff members for the various posts on this stuff, there’s a lot to read through and understand.