kristof65 said:
This is the type of thing that needs to be considered when the "tech" of the FTL drive is worked out - like the 100d jump limit was. Not something to be added decades later because it's a convenient means for a rule book writer to explain the tactics of an interstellar war.
It wasn't tacked on later - it was there right from the start. The Imperium wargame (on which GT:IW was based) originally only allowed jumps to go from star to star, and the only way to get to deep space was by sublight drive. So you could either spend a week jumping from one star to another, or spend years travelling between stars using sublight drives. The sections describing the history of the Vilani also describes how travel was limited by the range of their J1 drive, since the average distance between stars was 2pc - at least until they discovered J2. It also describes how the Terrans couldn't go beyond their own system using J1 until they discovered J2, and how they were stuck there for 43 years from the time J1 was discovered (in 2090, so according to Imperium J2 was discovered by the Terrans in 2133).
However, it also says that the Terrans set up a refuelling station partway between Barnard and Terra in 2113. Given the rules of the game they must have got to this refuelling point using sublight drives, and then must have jumped from there to Barnard, and given the rules stating that jumps could only be made between stars, and stars are massive objects, there therefore had to be a massive object in that intermediate hex. And obligingly, we know of massive objects that could be there now - Brown Dwarfs.
If that hadn't been the case, and large masses weren't needed to jump to and from, then the Vilani could and would just ignore stars completely and directly attack Earth from deep space (and the Terrans would ignore the stars and attack 1I worlds from deep space too), and the wars would turn out very differently. Since that didn't happen, massive objects MUST have been required for them to turn out the way they did.
And then subsequent CT texts set in the 1100s era say it's possible to do EHJs without needing stars there.
The problem really is that Imperium contradicts itself. The easiest solution to all of this would be to say that EHJ's weren't possible in the IW era and that the Terrans really were stuck in the solar system until they invented J2 - and then just push the date of the discovery forward to 2113. So when they broke out of the Sol system and met the Vilani, they already had J2. This only changes the history for the first IW, because by the time the second IW came around they'd upgraded to J2 anyway. And then, at a later point millennia afterwards the technology evolved and it became possible to do EHJs so that it was a normal procedure by the 1100s.
That would solve all the problems right there. Shift the Terran discovery of J2 back by 20 years, keep the evolution in technology that prevents EHJs in earlier periods an allows them later, and that's that.