Roleplaying in the Firefly Universe From the document: The appearance of FIREFLY in 2002 was a breath of fresh air in the science fiction scene. Breaking free of the tradition of latex layered aliens and sterile societies in a formless future, Firefly offered a grittier view of a human frontier that had to reach back into the simpler technologies of the Earth frontiers. User summary: The document (through Version 0.6a) was intended to be utilized with the "Mayonnaise for Firefly" roleplaying system. "Mayonnaise" was a variation on the rules presented in Fuzion. When the present document was updated to Version 0.7a all references to "Mayonnaise" were removed, leaving the document a generic resource for nearly any game system. Some of the weapons entries still include categorizations that apply to Fuzion, though they are quite generic. The document also suggests the contents would be quite suitable for the HERO System.