In the U.S., games are rated using ESRB; in Europe, they're rated using PEGI. This difference resulted in Microsoft inadvertently banning the likes of Skyrim, Call of Duty: MW3, and other Rated-M games from its Windows Store due to its policy prohibiting PEGI 18 games. Microsoft has clarified its position on the issue, and it turns out that it will sell “Mature” games after all.
We reported on October 11 about Microsoft’s apparent ban on ESRB “Mature” games in the Windows 8 App Store, which has been a recent source of controversy among gamers. Microsoft’s stated goal was a ban on Adult-Only games, something that is common amongst many services. The policy, however, prohibited PEGI 18 games.
PEGI 18 encompasses all of the ESRB Adult games, so on the surface, banning the rating seemed logical. The rating’s inclusion of many ESRB “Mature” games, however, caused a bit of a cohesion issue, and gamers were left wondering what games would end up falling through the cracks where these two rating systems intersect. Said Antoine Leblond, Windows Corporate Vice President of Web Services, "It basically ends up disqualifying games that would be ESRB Mature.”
Microsoft has clarified that it will sell ESRB Mature games in the Windows Store, and that it will be updating its policy relatively soon to reflect this. The reworked policy will allow Rated-M games to be sold in the Windows Store even if it falls under the PEGI 18 rating in Europe. The change will not go into effect until sometime in December.