A number of changes have been discussed and rejected multiple times, and sometimes discussed and ignored. Please review the below discussions before adding a new section for the parameter you would like to add. Each discussion is listed by most- to least-recent.
This template is within the scope of WikiProject Infoboxes, a collaborative effort to improve the coverage of Infoboxes on Wikipedia. If you would like to participate, please visit the project page, where you can join the discussion and see a list of open tasks.InfoboxesWikipedia:WikiProject InfoboxesTemplate:WikiProject InfoboxesInfoboxes articles
This template is within the scope of WikiProject Video games, a collaborative effort to improve the coverage of video games on Wikipedia. If you would like to participate, please visit the project page, where you can join the discussion and see a list of open tasks.Video gamesWikipedia:WikiProject Video gamesTemplate:WikiProject Video gamesvideo game articles
ESRB rates games in the US & UK on self-reported data to help inform parents if a given game, its themes and contents are age-appropriate for their children. In Japan, it's CERO.
The infobox for tabletop games includes a field for Age Range.