'User-Generated Content', also known as UGC for short, is a feature that allows users to publish their own items and sell them to other users. It is mainly associated with the Avatar Shop but can also be applied to other parts of the Roblox website such as Models and Plugins since they are techically also types of user generated content.
The accessories can be viewed under the Community Creations category in the Avatar Shop. The feature was initially announced at RDC 2015, but its confirmation was declared at RDC 2019. It released on August 15, 2019, to certified users on the site. Before its release, Roblox had confirmed that this feature will only be allowed to certain users who had previously worked with Roblox on different occasions for modeling and texturing purposes, with many suspecting that popular Roblox video content creators in the official Roblox Video Stars Program will have access to it.
Roblox has reached out to reveal that they will sometime in the future depend on content created by eligible users rather than prioritizing assets made by the official ROBLOX account, which is managed by admins to publish items as a default.
Whenever a user publishes an accessory, they can input customized descriptions, a Robux price, and much more. However, releasing limited unique items and making existing items limited is still restricted to ROBLOX. Roblox has stated that they want to move in a direction where creators can publish their own limited items to sell to other users, but are unable to reasonably allow this ability due to the minimal amount of creators in the program.
On December 6, 2019, it was revealed that star creators will be given the ability to request User Generated Content items to be created per TheMeganPlays' tweet. Some select star creators were given the ability to request an item early to test the feature. Roblox catalog managers originally let MeganPlays' item be created to test the feature, but her item was quickly turned into a blank item uploaded by the ROBLOX account. A copy of the item was later re-uploaded onto the catalog the afternoon that the original was deleted, and can currently be purchased. Currently, star creators are able to upload one accessory per month. 
On April 13, 2020, Roblox began testing for the support of Thumbnail Cameras in UGC items. The feature is currently not public.
List of UGC items
- Main article: Category:UGC items
Alternatively, click "Expand" to show the list of UGC items.
Go and buy some your self
Currently, there are only 47 known creators who are allowed to upload their own creations without request. Those selected users are:
There are also 7 selected accounts that were/are used for testing. These are:
The UGC feature has mostly been criticized due to potential copies of pre-existing catalog items by ROBLOX, low-effort, or unoriginal ideas. A notable example being some early hats by tarabyte (BiggestHead, Illuminati, Despacito Spider, and Triple Headstack).
UGC has also specifically been criticized by the trading community for fears of limited and limited unique items dropping in value. This originally began when the Downtown Denizen Fedora was uploaded by WhoToTrus and had subsequently been claimed by a portion of the community to be a ripoff of The Classic ROBLOX Fedora, despite the Downtown Denizen Fedora using a noticeably different mesh and texture on closer inspection.
The ability for creators to allow comments has also drawn criticism as the vast majority of UGC comment sections tend to be filled with spam chains unrelated to the item (such as "/e free" and "Post this on X items" copypastas) as well as generally harbored toxicity due to certain users personally attacking other commenters as well as the item and its publisher. They have often been compared to YouTube comment sections as both tend to be filled with children who primarily comment using text-based meme formats, along with many commenters seeking to start petty arguments with each other over their opinions.
On December 14, 2019, users in the Roblox Video Stars Program were granted the ability to publish UGC items at a slower rate than selected developers, presumably in response to YouTube's regulation changes regarding COPPA (effectively reducing ad revenue by a sizeable amount for kid-friendly content creators). This has been met with disdain by some users as they feel that Roblox is favoring video creators as opposed to developers, big and small alike. Additionally, some Star Program creators have been accused of uploading low effort items, with the most notable instance being the Golden Parrot by AntRavioli.
A trend among UGC items are waist accessories designed to look like a giant object, so a user can disguise your avatar as that object and fool other users into thinking their avatars in-game are part of the game map. A notable example is BOX. Because of how this can disrupt gameplay, scripts have been published in which they remove these kinds of accessories from avatars wearing them. As of recent, many of these items have been taken offsale, and it is presumed unlikely that this item trend will ever resurface.
JohnAvia was accepted as part of the UGC program, after posting many UGC concepts. It was then discovered all of his UGC concepts were plagiarized from other artists, which resulted in backlash against him. JohnAvia's items quickly got content deleted.
- A UGC item typically consists of a mesh created in a 3D modeling program such as Blender, which then has a texture applied to it and is imported into Roblox Studio for final checks before being published to the Avatar Shop.
- An early version of the upload interface can be found here, although it does not function if the user is not a designated UGC creator.
- Due to the current interface, sometimes hats will go off-sale when being updated.
- Creators cannot currently add scripts and particles such as Sparkles, Fire , and Smoke to their items.
- When uploading something, the item must have the "Plastic" Materials 
- Creators have to sign a "Non-Disclosure Agreement" (NDA) to create accessories.
- Premium is required to upload hats, and losing it will cause all pre-existing hats to go off-sale.
- ↑ https://devforum.roblox.com/t/thoughts-on-rdcs-ugc-announcement/327646
- ↑ https://devforum.roblox.com/t/ugc-catalog-is-now-live/331405
- ↑ https://twitter.com/MeganPlays/status/1203167916541263872
- ↑ https://twitter.com/MeganPlays/status/1202742288239267841
- ↑ https://twitter.com/KijiSoft/status/1264476378411368448