I love Traveler. IMO, it is the finest SF RPG to date. There have been slicker graphical presentations. There have been slicker rules presentations. There have been more “space opera” like SF games. There have been more “hard SF” games. There have been SF games that use iconic setups or characters. One and all, Traveler has buried them on an airless moon. Why?
Traveler has a character generation system that is simple but which immediately draws you into your character unlike any other SF game. The play of Traveler is also notable. Character advancement is not the main motive factor, as compared to other games. After character creation, your character is fairly well established. Thereafter, adventures are about what happens to your character without so much the omnipresent concern of “leveling” or gaining more “development points.” This makes preparation and play simpler, as well.
However, while the rules for Traveler are simple, the setting and its execution is complex, whether it be in terms of starship design, the details of a system/planet or the interaction of cultures and states. Yet, for all the richness of the setting, it precludes nothing and allows almost everything. It is simple at its core but can be made increasingly complex to suit individual tastes.
In a nutshell, Traveler is balanced and accommodates every style of play but without losing its essential “Traveler-ness.” One size fits all. Traveler is a universal constant, adaptable to whatever you may want to do with your SF game.
To turn the question around, why aren’t other SF games as good or better than Traveler? In a nutshell, most SF games -
(1) Model a very specific setup - the Star Wars universe, Space Opera’s Romans/Communists etc. in space, the Star Trek universe, Ringworld/Known Universe, Aliens universe, Living Steel, etc. - and are much less flexible or forgiving of adventures that deviate from the status quo of the universe being modeled; or
(2) Use a generic rules set - GURPS, Star Hero, etc. - that lends no particular sense of unique identity to the game, or
(3) Opt for “science-fantasy” - Buck Rogers, Star Frontiers, Alternity, etc. - rather than science fiction. This is an issue because science fiction can model science fantasy more easily than science fantasy can model science fiction because the unique tropes of science fantasy are at odds with the hardest elements of science fiction but the tropes of science fiction, even the hard ones, are encompassed within science-fantasy or can be easily co-opted.
All of these games can be fun. Many are good games. Traveler, however, stands out and has demonstrated a unique staying power because it does/can do what the aforementioned do plus more than any of the aforementioned, in a more memorable way (meaning in a mechanically simple, “non-leveling,” thus story-centric, way).
IMO