User blog comment:Equillibrium/Elder Scrolls Online Gets ESRB Rating/@comment-8248675-20140123153333/@comment-3124449-20140125025616

Games are only rated on the content included in the base game. That's the "ESRB rating not based on online play" message when you open a game. Also, literally any game can use a nude mod. You could apply one to Super Hexagon if you really wanted to.