I first began running my Star Trek RPG using the FASA Star Trek, The Role Playing Game rules system in 1983. Although there had been various SF games around for awhile, none of them really fit Star Trek comfortably. FASA's rules were obviously written by Star Trek fans as well as game designers. While not perfect, the game was skill-based and used percentile dice. The character generation system created a believable, well-rounded persona with a history! Sure, Traveller characters had histories as well, but they usually only had a handful of broad skills, and a good chance of being killed during character generation!
My original Star Trek: Excalibur campaign ran for nearly ten years using the FASA rules before I began using a hybrid House Rules system based loosely on GDW's Twilight: 2000 and Timeline's The Morrow Project. FASA had lost its license, and I was unhappy with some of the FASA game's foibles. When I moved my campaign to the 24th century Next Generation milieu, I converted the whole thing over to the House Rules.
The Star Trek: Universe campaign uses the ICON gaming system by Last Unicorn Games. LUG's Star Trek, The Next Generation Core Rule Book was first published in 1998, filling a gap left by FASA's earlier effort. It complemented some of the nicer bits of the older FASA game, and demonstrated a fine understanding of the Star Trek philosophy. Again, it was skill-based and used a single type of die - six-sided in this case. Star Trek: Relic, the first campaign within the larger Star Trek: Universe metacampaign, was born. LUG also gave me my first chance at writing game materials professionally - my debut effort, "The Sword of Honor" (sic), was one of LUG's demo games at Origins and Gencon in 2000. My thanks goes to Ross Isaacs, the enormously talented and infinitely patient Next Generation Line Developer at LUG, for giving me that opportunity. It was the first (and possibly only!) Klingon piece released by LUG, a direct sequel to the Star Trek: Deep Space Nine episode "The Sword of Kahless."
In mid-2000, LUG was bought out by Wizards of the Coast, and the license was transferred to Decipher, the publisher of the Star Trek Collectable Card Game, effective January 2001. Decipher hired most of the former LUG designers to write a new Star Trek RPG, and conducted playtests of their new system throughout 2001, and released the first book for their CODA system, the Players' Guide in early 2002, followed up by their Narrators' Guide during the summer of 2002. I'm afraid, however, that I won't be switching to the new system, for two reasons. First, I don't care for the game mechanics - modified "class-and-level" doesn't cut it for a 21st century SF game - I quit playing Dungeons and Dragons over 20 years ago largely because of the class-and-level system. Second, I can't afford it. The Player's and Narrator's books run fifty dollars (Canadian) each, and you need both to run the game. OUCH!
On the other hand, it's a popular system with some folks. It is, after all, written by the same talented folks who wrote the ICON version, and they've made a solid effort to maintain a continuity of background with their old ICON materials. Decipher is slowly adding to the line, with the Narrator's Screen and the new Starfleet Operations Manual.
There are, of course, alternatives . . . The first set of Star Trek rules were the Star Trek RPG rules by Lou Zocchi's Gamescience. An adaptation of Zocchi's Space Patrol/Star Patrol rules set, the game was primitive in the extreme, and barely playable. Currently, there is an unofficial Star Trek sourcebook for Steve Jackson Games' GURPS available on the Web; there is the old Star Fleet Battles-based Prime Directive RPG from Task Force Games/Amarillo Design Bureau; and there is the current GURPS Prime Directive from SJG. I find GURPS unplayable. In trying to be generic, it has leached all the individuality out of gaming, and again, you need half a dozen books even to play the game. Prime Directive, being based on the Star Fleet battles universe, diverges wildly from Star Trek, most notably in its very militaristic tone. GURPS Prime Directive suffers from both these problems. Okay for some people, but not for me, thanks.
Personally, I'm sticking with ICON - the ICON System isn't dead! The good folks at Don Mappin's TrekRPG.Net website are producing a number of fan-written game supplements. Several of the people who wrote for LUG are releasing unpublished ICON material, including SpaceDock (starship construction and expanded starship combat rules) by Steve Long, former DS9 Line Developer. Links to these materials can be found at TrekRPG.Net by clicking on the link below.