When I first purchased "Traveller", way back in 1977, I found the three-book boxed set at a book shop that stocked games (a two-hour road trip to a neighboring city). For months that was it. Then "Mercenary" followed, and after a bit longer the first pre-packaged adventures started showing up and, within a year, the Imperium was fully established and being fleshed out.
I always had the impression that the "Imperium Universe" was an addition to, but not a part of, the Classic Traveller rules. T5 certainly gives the impression otherwise although, off the top of my head, there is little in the mechanics that "demands" a specific setting although social status strongly implies certain assumptions.
Just my $0.02.
I always had the impression that the "Imperium Universe" was an addition to, but not a part of, the Classic Traveller rules. T5 certainly gives the impression otherwise although, off the top of my head, there is little in the mechanics that "demands" a specific setting although social status strongly implies certain assumptions.
Just my $0.02.