The Elder Scrolls Online is officially a game intended for "Mature" audiences, as rated by the ESRB. The announcement was released January 22nd via the official Facebook page
The ESRB advised us that it has given The Elder Scrolls Online a Mature rating. While we may disagree with the ESRB’s determination, we do not plan to challenge the rating, and we are unwilling to change the game’s content to achieve a different rating. The game we have created is the one we want our fans to be able to play.
As a result of the ESRB rating, we are in the process of promptly updating everything with the required rating and age gates, including game trailers, web sites, and ads. Thanks for your understanding. We can’t wait to welcome players into The Elder Scrolls Online soon.
ZeniMax clearly expected and intended for the game to achieve a "Teen" rating for a broader potential audience. However, those hoping for a more mature overall theme and the potential for gorier graphical details will likely be pleased with the ESRB's determination.