I've had Homeworld on the brain recently. There was something remarkable about the atmosphere of Homeworld, and I've been struggling to put my finger on it.
For all that space resembles an ocean, and is full of cruisers and such, in Homeworld space is also a desert. The backgrounds are often bright nebulae, red and orange and purple, rather than the starry blackness one associates with space games, and visibility is sometimes restricted in a way that resembles dust more than anything nautical. Names like Seljuk and Sojent-Ra, peoples organized not in states but tribes (eg Kith Somtaaw). The combat music is drums and pipes and horns, not at all space-age. The storyline of Homeworld 1 is accurately summarized as "Exodus on a spaceship", and the Garden of Kadesh is full of religious fanatics. The juxtaposition of the ancient and the futuristic is powerful; technology may change, but people don't.
There is a certain desolateness and desperateness about the whole affair. A whole lot of empty, and of salvaging. There's a bit of post-apocalypse in it as well; your small craft can run out of fuel and be stranded, and the ruins of the ship graveyard tell of fallen empires of immense power (those are capital ships he's panning around).
And it makes sense. The universe is a desert. Space is big, and empty, and inimical to mankind. It is very hot and very cold. There is nothing to drink, nothing to eat, nothing to breathe. Beautiful in its starkness and vastness.
So the question on my mind is, how do I bring that feeling to Traveller? I mentioned Classic Trav to the group the other day, and ultimately realized that there's a bit of confusion about what you're supposed to do in Traveller. Part of this is that the source fiction is not stuff familiar to us (Space Viking? The hell is Space Viking?). It's from a completely different era of science fiction than we are. It's pre-transhumanist, pre-Singularitarian, pre-cyberpunk, practically pre-Star Wars (I recall seeing stats for "Luke Starkiller" in the Classic Traveller book of NPCs, but he's a farmboy pilot with no psionic powers, from when Star Wars was the name of a single movie rather than a franchise). Probably the closest things I've read were Dune and Foundation, and neither of those 1) seem like particularly plausible futures to us, or 2) are particularly gameable.
Another part of the problem is that Traveller does not have the clear progression you see in D&D, from low to high levels, or adventurer to king. There are lots of little subsystems that let you do all kinds of different things but it's not clear what you should do. So I think, if I were to run Traveller, that some sort of objective function would be a welcome addition. Absolute freedom paralyzes absolutely.
But anyway, some thoughts for "Space is a Desert":
Rare Oases: Gas giants 1/3 as common as usual, jump uses 1/3 as much fuel as usual.
Despoiled Gardens: Most planets were never going to support human life. The ones that were, humanity did to as humanity does, and now they barely support human life either.
Babylon: An empire collapsed or collapsing as a result of its hubris, decadent sin, and barbarians at the outer reaches.
Your money is useless here: If the universe is shattered into little isolated autonomous clans, and there is no faith in the Imperial Fiat Currency, suddenly Traveller's trading minigame actually matters, because you have to carry your wealth in goods that you can trade when you arrive. Pretty good bets: spare parts, food and hydroponics, chemical air filters, maybe weapons.
The Ruins of Empire: Sometimes spacers run out of fuel, orbital stations suffer a life support failure, and colonies die out due to plague, inbreeding, wildlife, civil war, environmental catastrophe, or whatever. Loot, ho!
Life Support: There's actually a rule about shipboard life support, and we have traditionally ignored it. Wastewater is easy to purify given fusion-heat and CO2's pretty easy to scrub chemically, but the complex organic foodmolecules required to sustain human life are much less common in the cosmos than the hydrogen required to power the reactor.
Light Cavalry: Emphasis on high-speed light units; in the space context, fightercraft. Maybe not sensible, but traditional. Paint some heraldry on that fuselage and make ready your particle-lance.
Swords: Nothing says Ancient Future like some bloke trying to cut your vacc suit open with a scimitar. If the orbital habitats aren't as sturdily-constructed as is typical in Traveller, firing a gun indoors may be a one-way ticket out the airlock by civil convention, and melee combat the norm aboard ships.
Hokey Religions to go along with your Ancient Weapons: When the situation gets grim, people go crazy and start hearing gods. Always have, always will.
No Pirates: There will always be those who seek to use force to take things of value, but "pirate" is too naval a term. Brigand or bandit might serve. Homeworld used "Turanic Raiders", and I could see using barbarians. Unfortunately no really evocative word that means quite what I want is springing to mind.
If I were to steal a little more from Homeworld, rather than just thematically, I might throw in:
Back into Space: The players' home planet has been cut off for a long time, and recently re-discovered jump drive. The PCs are the first out to do reconnaissance, and are Astronaut Material (former test pilots with two PhDs, you know the type), which might have some effects on chargen... and then there's an exploration game, where scientists are useful for eg looking at exoplanet spectra for atmospheric composition to see if there's a gas giant in-system before jumping in.
Fleet Command: The trouble with using Starmada in Traveller typically is that it's too deadly, but if you have multiple ships, that problem diminishes. And Stars Without Number has such tempting rules for building battleships as a PC activity... There's a lot of other good stuff in SWN that I should steal, particularly on the worldbuilding front.
To the Stars: Having been stuck on a desert hole of a world, some folks on the PCs' homeworld are going to want to move to space if opportunities arise. Ties nicely to the exploration game (finding habitable worlds) and the fleet command game (keeping them safe).
Relatedly, if I were to steal a couple of things from ACKS, they would be henchmen/hirelings (should be simpler than ACKS' henchmen, and you need crew for your ships...), reaction and morale (which Traveller already sort of has), maybe mortal wounds (or something like them, as an excuse for cybernetics), and, uh... not much else. Oh, and ACKS' initiative system, actually - it could make autofire initiative penalties and leadership/tactics initiative bonuses interesting for once.
If I were to steal just a few things from Classic Traveller, I'd strongly consider weapon-vs-armor tables and the increased encumbrance limits. Weapon-vs-armor tables do a marvelous job resolving the Armor Problem we've had with Traveller in the past, that anything that can hurt the guy in combat armor will instantly pulp anyone else. With weapon-vs-armor tables, an anti-armor weapon (say a high-velocity rifle) can hurt the guy in heavy armor, but won't instagib everyone else. For simplicity's sake you could even do something like just having two main types of armor (hard and soft) for attack DM modifiers, and then some small DR values and weights differentiate within those types.