so impressed with it that his company TSR published Empire of the Petal Throne in 1975. TSR published Barker's game and setting as a standalone game, rather than as a "supplement" to the original D&D rules. Another early game was Traveller, designed by Marc Miller and first published in 1977 by Game Designer's Workshop. This was originally intended to be a system for playing generic space-opera-themed science-fiction adventures (in the same sense that Dungeons & Dragons was a system for generic fantasy adventures), but an optional setting called "the Third Imperium" that was detailed in subsequent supplements became strongly identified with the game. The changes in this setting over time, especially those involving "the Fifth Frontier War" as depicted in the Journal of the Travellers Aid Society, arguably constitute the first use of metaplot in a role-playing game. Mid-1980s to early 90s: diversification of settings and systems Up to this stage, each game had tied itself to a particular setting; If a player wanted to play in a science-fiction game and a fantasy game, they had to learn two game systems. Attempts were made in Advanced Dungeons & Dragons to allow cross-genre games using Gamma World (1978) and Boot Hill (1975) rules, but the obscure rules went largely unused. Meanwhile, Call of Cthulhu and Paranoia offered different role-playing experiences, in which the story arc of a group's investigation would lead to death and/or madness, or where comical infighting within a group would be expected and reinforced within the genre conventions of "a darkly humorous future". The Hero System, first introduced in Champions (1981), was also used in Justice, Inc. (1984), Fantasy Hero (1985) and other games. Steve Jackson Games followed with GURPS (the Generic Universal Roleplaying System) in 1986. At the same time, games using the fictional worlds of Star Trek, DC Heroes, the Marvel Universe or The Lord of the Rings expanded the range of possibilities for Table-top gaming. Games such as GURPS and Champions introduced character creation via point-buy systems; later, Vampire: The Masquerade and similar games emphasized storytelling, plot and character development over rules and combat. Due to the game's success, the term Dungeons & Dragons has sometimes been used as a generic term for fantasy role-playing games. TSR undertook legal action to prevent its trademark from becoming generic. Dungeons & Dragons was a subject of controversy in the 1980s when opponents such as Patricia Pulling claimed