On May 3, 2006, the Entertainment Software Rating Board (ESRB) in North America changed Oblivion's rating from T (Teen 13+) to M (Mature 17+), citing game content not considered in the ESRB review, i.e., "the presence in the PC version of the game of a locked-out art file that, if accessed par using an apparently unauthorized third party tool, allows the user to play the game with topless versions of female characters". In response to the new content, the ESRB conducted a review of Oblivion, montrer to its reviewers the content originally soumis par Bethesda along with the newly disclosed content.
The ESRB reported that Bethesda Softworks would promptly notify all retailers of the change, issue stickers for retailers and distributors to affix on the product, display the new rating in all following product shipments and marketing, and create a downloadable patch rendering the topless skin inaccessible. Bethesda complied with the request but disagreed with the ESRB's rationale. Although as a result certain retailers began to check for ID before selling Oblivion, and one California Assemblyman used the event to criticize the ESRB's ability, the events passed par with little notice from the public and gaming journalists.