Even at J-4, the Terran region is very cut off from the rest of Charted Space. As I've tentatively decided before, there's Chirper-mediated connection between the Zhdezi and Terran interiors (hinterlands, in the Terran case) but that's pretty much just spy/smuggler stuff.
Militarily, that makes the Terrans both very well-defended but also very cut off when it comes to expansionism, something that historically authoritarian governments have found pretty important in keeping their citizenry under control. I've suggested the Terran hinterlands might be less well-controlled, and I think maybe that's where the expansionism comes in: the Earth-based government's outer territories were more loosely held, and they broke off when the authoritarianism set in. (Or maybe the cause and effect are reversed, I dunno.)
The question is what that does for game setting, of course. For an Inukari campaign, it cuts off Terran space for a casual tramp freighter visit. But it makes for a Star Wars rebellion-against-Empire sort of setting, for campaigns that are set there to begin with. It does pretty much eliminate some of the options for non-human characters, though, since Gvazda/Wolves will be all but forbidden and Chirpers will be distrusted at best.
No kings, but maybe an emperor?
Terrans are definitely ending up the bad guys here, sort of: as with any authoritarian government, they've built in their own people as enemies so really, the "Terrans" likely to be encountered outside their territory are least as likely to be anti-authoritarian ex-pats and refugees as authoritarians. I'm not quite sure what their government paints itself as, though.
(Aside: Traveller, and to a lesser extent other roleplaying games, made me learn a lot more about this sort of thing than social-studies classes ever did. Gotta understand our world to build other ones!)
I think I'll tentatively use Italy's fascist period, though if the model doesn't fit I'm not going to force it. Or maybe the Roman Empire, but that feels too overdone.
A problem with declaring someplace "authoritarian," especially an entire interstellar region, is that it's fundamentally not a stable form of government. Which may or may not be a bad thing (game-wise): it may be a region of constant war and power shifts and whatnot, which is great for soldiers of fortune. I have kind of (and always have) ignored a large chunk of what evidently defined Traveller for a lot of people: the mercenary company campaign. Murder hobos, just more honest about it. (I jest, mostly: none of the tramp-freighter campaigns I was in was really a murder-hobo type thing.)
Expansionism
Update: There is now a wiki entry for jumpdrives, which supercedes this.
Further to the idea of distributing the species (and subspecies, in humanity's case), I am starting to feel like the four separate areas are a little too separate, and probably the best place for a campaign is right after jump-4 ships become possible.
That greatly increases the connections in the Ring, re-connects the isolated cluster in between the Inukari and the Wolves... and also connects the Wolf Worlds with the Inukari territory. Zhdezi space is much more open to the Ring, but neither Inukari nor Terran is, and the rift between Zhdez and Terra is still J-5+.
So the Wolves would be all over the hinterlands of Inukari territory if they got J4, but also they would have access to the previously-unknown worlds in the upper right, which I think are the hani. I mean, the Aslan. Uplifted prehistoric felines, at any rate.
Traveller pretty much has fixed drive ranges regardless of tech level: if you can build it, you can get full distance out of it. I prefer to have advances work differently: at lower tech levels, a J-1 drive is much larger than it is at higher levels... and at those higher levels, it's possible to refit those giant drives with more efficient whozits. Something like: the drive is producing a certain amount of "jump energy," so to speak, and if we improve the control over it we can use it more efficiently.
Yes, that's hand-wavy. But, and this is the key thing, it can mean if the players can get hold of a better controller, their ship can go faster. This seems much more doable than getting hold of a faster ship in the early days of that technology.
This is even more doable if it's just a software upgrade: what if some kind of better compression algorithm suddenly makes a J-2 ship J-3 capable?
Or a J-3 Wolf fleet J-4 capable?
Species distribution
Players like to choose non-human, non-baseline things to play, so while if it were a fiction world I'd be inclined to keep the Wolves out of human spaces as much as possible, and make Dragons pretty rare and insular. But it's a gameworld, so there are probably actualy quite a few lone Gvazda around. And, inexplicably, Dragons with J-4 ships that haven't been economically coerced into running very efficient, regular routes for shipping combines.
Likewise, if I were Zhdezi I would stay in my fully automated luxury gay space commune instead of mixing it up with the mind-blind savages, and yet. Terrans would be stubbornly sticking in their Real Human spaces, where men are men and women are subservient (okay in fact there are probably a lot of dissatisfied expats from there).
I'm also thinking maybe Zhdez uplift their gorilla and/or dolphin analogs, just to give me a few more non-human things for PCs to be. That's something else I'll have to let percolate.
Space trucking
Speaking of space trucking: Red Limit Freeway is on sale at Kobo (and presumeably elsewhere) for a couple bucks. It's the one series that makes me occasionally inclined to allow entering jump from a planetary surface, though I'm not sure I want to deal with the ripple effects of that. Probably.
In that trilogy, interplanetary travel happens through gates, set up by incomprehensible aliens, who also have connected them with self-repairing roads. One has to negotiate the gates, at speed, and so the "starships" are space trucks: capable of handling whatever oddball worlds they have to travel through (some of which don't have atmosphere, etc). It's neat worldbuilding, and it does have some influence on my "network of worlds that may or may not have been set up by precursor aliens."
Minimum viable starship
Traveller has a hard limit of 100 dTons as the minimum starship size. That feels a little high. Now, I forget what the minimum practical size would be, extrapolating a smaller drive (the minimum one gives a 100-ton ship jump-2) and so forth, but with Traveller's fuel requirements I think it's still around 50 tons.
One thing that felt wrong about Star Wars was Luke effing off in his teeny little X-wing, through hyperspace. Nope. Fighters need tenders, aircraft carrier types, they don't just go zooming about the universe.
On the other hand, Traveller pretty quickly came up with the X-boat, little express starships with ridiculous range that carried the mail. And that's fine: there should absolutely be the possibility of a Pony-Express type thing, the farthest-range drive there is (so: J-3) with a cockpit and a maneuver drive and enough cargo to carry a little mail. In Trav they're 100 tons which, sure, fine, whatever, you need that much space for J-6 worth of water-fuel, but I think in my system they'll have to be a little smaller.
Just not X-wing small.
Disaster recovery
I've been thinking about what happens in a system after a disaster, given the speed-of-starships limitation on communication. I'm here assuming a worldwide disaster: something affecting an orbital station, or the tiny settlement on a low-population world, or something along those lines.
Assuming someone immediately goes for help, that's a week. And a week for any help to come back, after whatever time it takes to organize whatever sort of help is needed. That is a pretty good window for "Only The Player-Characters Can Help."
Within the various interstellar polities, there's probably something like FEMA, that can respond to various disaster types. There are probably regional bases with ready-to-go modular headquarters and housing and whatnot, though it'll still be weeks or even months depending on what happens and where.
It means planets are pretty vulnerable to attack without a rapid response, without military bases and patrols. The small size of the map means simple piracy is a little less of an issue, except across borders - but the bottlenecks leading to/from each separate area make that pretty controllable. So I guess we can assume that Sundtia has a pretty solid naval presence. And/or maybe Adriannia, though I think the Zhdez probably are a bit more proprietary about it.