Xbox One will allow developers to add Achievements to their games after release, but Microsoft's policies will ensure that add-on Achievements "don't get out of control," Chad Gibson, Xbox Live's principle group program manager, told the Official Xbox Magazine U.K.
Cierra McDonald, program manager for the Xbox Live Achievements service, explained the new achievement system last month, which will allow developers to add new achievements to their games through cloud-based updates.
Gibson said that Microsoft decoupled the achievement system from the game code to allow this functionality.
"We want game developers to be able to offer Achievements and interesting opportunities throughout the life-cycle of a game," Gibson said. "So, you know, 14 months after the game's shipped, you're still offering interesting Achievement opportunities, because users are still playing the game, and the game is still evolving and growing."
Microsoft is aware that exponentially adding achievements could overwhelm players, and Gibson said that the company has taken steps to curb that potential behavior.
Microsoft is "super-sensitive to people who are worried about wanting to get all of the Gamerscore," he said, "so we still have policies for developers to make sure that things don't get out of control. Like, we do not want a game offering 10,000 Gamerscore every day. We still have policies, so that user experiences are rational - users have an opportunity to complete everything without feeling constantly overwhelmed."