Free Models are Models that are saved on the ROBLOX website for others to use in their places. Free models can be found in the "Develop" tab in the navigation bar, then by clicking on "Library", or by going in ROBLOX Studio's navigation bar and clicking on "View" then "Toolbox".
Some free models are known to contain malicious scripts (e.g a brick/model that spreads fire upon touching the parts with the script). For this reason, most veteran users stay away from free models. A good way to make sure a model doesn't have a infection script is to check all the parts in the model in ROBLOX Studio. Most are found in the form of a weld and the name is often something obvious to its intention, such as "u got pwnd". These kinds of scripts date back to 2008. If you see these 'virus' scripts, delete it. Many of these are usually named "ERoblocker", "dåååååååång..............you got owned", "4D Being", "Vaccine", "ROFL", "ViVrus" and "H75".
There are many anti-virus scripts and plugins on the ROBLOX website. The bestselling plugin that combats infected models is Ro-Defender™, which automatically detects and removes viruses and infected scripts from inserted free models.
Endorsed models are models that are made by members of RBXDev. They are high quality models approved by the ROBLOX staff that follow specific criteria, such as they must work with FilteringEnabled, must look professional, aren't anchored/are intractable, don't use copyrighted material, the scripts are commented heavily, and don't depend on other models (ex: can't require other modules from the site). The people who make these models get some ROBUX as compensation and get their model displayed before all others and have an orange icon. These models will never be infected because they are made by reputable people and are endorsed, meaning they are heavily scrutinized.
Despite multiple occasions of ROBLOX encouraging the use of Free Models, they are often frowned upon by the community. Much of the community believes the use of free models indicates a lack of effort on the creator's part because they used another person's work (and often without giving credit to said person) instead of creating it themselves. This shows a lack of creativity and commitment to create a game with fully original assets, which in turn means that they are a bad developer, hence, breaking any trust the end user may have with their game.
- There have been multiple instances of users being able to sell Free Models for ROBUX. The users who sold these models were banned soon after.