|Publisher(s)||Green Ronin Publishing|
While working on Silver Age Sentinels, Steve Kenson pitched Freedom City as a setting for the game, but the game's publishers, Guardians of Order, turned it down.:337 Chris Pramas of Green Ronin Publishing asked Kenson to design a new d20-based superhero RPG. Kenson developed Mutants & Masterminds in 2002. In 2003, his Freedom City setting was published.:371–372 Green Ronin published a trio of books – Golden Age (2006), Iron Age (2007) and Silver Age (2010) – which developed Freedom City by examining it through three different comic book eras.:375 In 2008, a new series of Freedom City Atlases expanded the original Freedom City setting.:375 A new third edition of Mutants & Masterminds Hero's Handbook (2011) brought a new setting to the game universe, Emerald City, which first appeared in a series of PDF Threat Reports (2011), with a complete setting book planned for GenCon 44. Lastly, a third edition Freedom City book was published in October 2017 which advances the timeline and introduces new characters while retiring others.