In-game ban

An in-game ban is usually given to the affected user by an administrator of the place or server. Therefore, this forces the affected player to exit the game. There are few ways administrators in places can ban players from entering, or remove players from the server. These can range from being kicked or being permanently banned from the game.

However, players who are banned from a game may play other games, or re-enter (if the player is kicked or un-banned by the administrator).

However, banning people in-game is a violation of the Terms of Service. If you are caught banning people for no reason by ROBLOX staff, consequences will result and your account could be banned.

Commands (used by Administrators)
Administrators in games have power to remove players from their servers (as well as affect other players). They can use these commands to remove players who do not follow game rules or affecting the environment of a server.