The last way to join a specific Roblox game is if players have friends playing in that server. They are able to join any friend's game if they have the "Join In-game" setting enabled.

You can create your own clan and invite people, or join an existing one, the choice is yours. This guide contains step-by-step instructions on how to create and join a clan in Roblox: Blade Ball.

Out of the many unique experiences available on Roblox, the developer 35px has gone one step ahead and created Every Roblox Player.