EB Games has joined the effort to introduce a mature rating for videogames in Australia, reports Joystiq.  Australia has been embroiled in a battle between game makers and government officials over its lack of a rating for games equivalent to other territories’ 18 years-and-over or M-Rated classifications.  The country’s ratings classification board recently launched an initiative to get the public to weigh in on whether it should begin using its mature-film equivalent R18+ rating for games.  EB Games has joined that initiative by starting a petition gathering signatures to forward to the government through its own web site, Grow Up Australia and EB Games.  The game retailer isn’t being subtle about where it hopes to lead the vote.  “What comes as a shock to many is that Australia is the only developed country without an R18+ rating for video games.”    Read more at Joystiq.