Two different Role-Playings Games (RPG) have been produced and one online game is under production.
The Serenity role-playing game was produced by Margaret Weis Productions, Ltd and released in 2005. Its mechanics are the first iteration of the Cortex System.
In 2013 Margaret Weis Productions announced they had the rights to produce a Firefly role playing game and would be producing it using a slightly different system.
On December 8, 2006, The Multiverse Network announced that it had obtained the rights from Twentieth Century Fox to develop a massively multiplayer online game (MMO) based on the series. As of 2008, little progress had been made. On 3 September, 2008, as part of a press release announcing the development of an MMO based on the Buffy the Vampire Slayer television series, Multiverse stated that work on the Firefly MMO had been delayed as there were "some issues that need to be worked through", although some gaming news sites have expressed doubts, based on the lack of progress with the Firefly MMO, about whether or not it will be completed or released.
On January 2, 2012 website Ten Ton Hammer uncovered documentation that Multiverse, the team behind both the Buffy The Vampire Slayer and Firefly MMO projects, had ceased operation on both games as of December 7, 2011 due to lack of funding. However, on January 5, 2012 former members of the Multiverse team announced that they had acquired the source code and were still working to develop a finished product.
On July 18, 2013 it was announced at Comic-Con that a mobile game titled "Firefly Online" would be released in Q3 2014 for Android and iOS. This game will not directly continue the franchise's plot but players may be able to meet the series' characters in it.
On July 28, 2014 it was confirmed that the leads of the series had signed on to voice their characters in the game and the release would probably in 2015.