API endpoints on the main domain e.g. https://www.roblox.com/groups/2/games/1 are either legacy endpoints or meant for internal use. Instead, Roblox provides officially supported endpoints in the form of https://_______.roblox.com/docs, but there’s no documentation listing all of these. Most of the time they’ve been found, it’s on accident (noticing them pop up in http requests from the main site) or a staff member posting “Oh did you know we had _____?” on the devforum. It’d be great if the wiki had a list of all of them.
Here are the ones that I know of so far (either posted by staff or pop up in web requests from main site):