What RPG has the best spaceship design system?

[Rupert]

One thing to consider is what sort of shiny spaceships you want the system to encourage. Do you want a setting where it's "WWI in space"? Or "WWII in space?" Or maybe "The Cold War in space" or "galleys in space".

This often boils down to it being a 'big ship' or a 'small ship' setting. One where ships can carry weapons that easily destroy other ships regardless of size will encourage small (and thus cheap) ships. One where only big ships can hurt other big ships will tend towards warships becoming as large as the governments paying for them can afford, assuming no other limited exists.

As all spacecraft are moving through the same medium (magical drives aside), the aircraft vs ship distinction that so affected WWII naval warfare doesn't apply, so getting 'WWII in space' requires some fairly arbitrary rules and/or technological features, and is very hard to balance so that it's vaguely balanced and fun. Of course, if you're planning a game where everything is in transition to (or from) carriers, this won't be a problem.

Most WWII in space rules I've seen seem to expect it to be a sort of steady state, where powers will be battlestarships and carriers plus their 'fighters' and they'll all be useful. They'll probably have some sort of battlecarrier with fighters and guns in there too, and the rules will bend around it to make it actually useful.

[Fred Brackin]

Originally Posted by Rupert

My recollection of that system is that how fast ships were and how manoeuvrable was strongly based on what hull you chose and was pretty arbitrary.

There were breakpoints for speed and maneuverability but the really dubious areas involved engine size and number. One I remebr was that a size 19 ship required 4 class "C" engines but the size 20 ship (one larger) needed 8 for the same speed and maneuverability. Size 19 ended up being a lot cheaper.

The rules could also be arbitrary and simple but nonsensical. Ships carried one unit of cargo per size class. I think size 20 was something like 100x longer than size 1 never mind the other 2 dimensions.

[RogerBW]

There's presumably some foundational work of 1950s-1960s SF that defined the orthodoxy of WWII-like ship classes in space, but I haven't read it. (Certainly Traveller took it on board.) My general feeling is that even if you have crewed combat spacecraft in the first place, justifying space fighters is really hard without the advantage of a different medium to work in.

"So You Want To Build A Spaceship" (Pyramid3-94), which Timothy Ponce and I co-wrote, talks about how to select options in the GURPS Spaceships design system to get a particular feel.

[Anaraxes]

Originally Posted by RogerBW

There's presumably some foundational work of 1950s-1960s SF that defined the orthodoxy of WWII-like ship classes in space, but I haven't read it. (Certainly Traveller took it on board.)

I suspect the existence of fighters and carriers in Traveller was mostly influenced by Star Wars and Battlestar Galactica, rather than anything from the 50s-60s. I'm not recalling much, if anything, written in those decades that was carrier-battle-like. (Most of the military SF was more tightly focused and planet-based -- Starship Troopers / The Forever War / Armor, Dorsai, Hammer's Slammers, Pournelle's Falkenberg books.) People that wanted to make WW2-like movies or books were generally still just cranking out war movies set in the actual war at that point.

Starfire was intentionally directly modelled on WW2 (made obvious from the thinly-veiled events in the progression in its future history).

My general feeling is that even if you have crewed combat spacecraft in the first place, justifying space fighters is really hard without the advantage of a different medium to work in.

The key tactical features the setting needs to feel like WW2 carrier warfare are (1) small ships are significantly faster than bigger ones (10-20x the speed), but much more limited endurance (so they have to be carried and refueled); and (2) small ships have a much larger range than ship-mounted weapons (again, a factor or 10 or 20). You'll also probably need to limit the sortie rate with some restocking rules for the fighters, unless the travel times vs. distances in the rules alone take care of the differences. So, the space drive mechanics need a pretty quick penalty based on ship size. On Earth, in WW2, that came from different mediums to move through, but that doesn't mean you need two different kinds of space. (You will already have them

All the big boring space works in your favor, though it's much to justify spotting without weather and limited detection ranges (whether from atmospheric effects or the curvature of the Earth limiting radar ranges).

The harder thing to deal with IMO is explaining why you need the pilots instead of launching drones / AKvs or expendable missiles. You need expensive high-speed drives to make missiles unattractive, and (from a modern point of view) remarkably dumb computers to need a dashing human in a cockpit.

With all that, though, the space-naval warfare should feel like carrier warfare. It still won't look a lot like Star Wars, though. The battleships won't usually directly mix it up while also throwing out the fighters that they also carry. You do occasionally get fighter-only strikes at a distance in those shows -- out of necessity at Yavin, as that's all the Rebels had, more commonly in BSG, which sticks closer to its WW2 inspiration with the speed difference and also the fact that the battlestars and base stars aren't really heavily armed compared to their fighter complement, just a bunch of AA weapons and one or two BFGs making special appearances in a couple of episodes -- probably needing some spinal mount type rules.

[Varyon]

Originally Posted by RogerBW

My general feeling is that even if you have crewed combat spacecraft in the first place, justifying space fighters is really hard without the advantage of a different medium to work in.

As Anaraxes notes, you can copy a lot of the relevant bits of watercraft vs aircraft, even with both going through the same medium. Your watercraft analogues (capital ships) need low speed and mobility, but high endurance; your aircraft analogues (fighters) need to be just the opposite - high speed and mobility, but low endurance.

Personally, what I think can make capital ships vs fighters interesting is for the latter to have markedly better close-in accuracy but lack the power to directly take down the former. Instead, the fighters serve to take out the close-defense or long-range anti-capital-ship weaponry on the enemy capital ship (or take down the shields, or whatever), which allows (depending on which you took out) either for boarding transports to attach (taking over and/or destroying the ship from the inside) or your own capital ships to blast them to pieces. Fighters are also often your best defense against other fighters, of course. Note this is largely reliant on your spaceships being unrealistically resilient (realistically, a small fighter can carry enough firepower - possibly simply in the form of having high relative velocity - to annihilate a capital ship, particularly if nukes are available). I also suspect it's not the kind of thing OP is looking for, but I may be mistaken.

[Michael Thayne]

Originally Posted by Rupert

One thing to consider is what sort of shiny spaceships you want the system to encourage. Do you want a setting where it's "WWI in space"? Or "WWII in space?" Or maybe "The Cold War in space" or "galleys in space".

This often boils down to it being a 'big ship' or a 'small ship' setting. One where ships can carry weapons that easily destroy other ships regardless of size will encourage small (and thus cheap) ships. One where only big ships can hurt other big ships will tend towards warships becoming as large as the governments paying for them can afford, assuming no other limited exists.

I tend towards "Cold War in space" and "small ships", but am open to a variety of approaches if it all hangs together logically. One thing I would like to see more of is sophisticated missile-design rules, since I don't see how you get a spacefaring society without also having some incredibly destructive missiles, thus making missiles very important to space combat. And if you want to boost point-defense to mitigate that, the implications should be applied consistently across the setting.

[Fred Brackin]

Originally Posted by Michael Thayne

I tend towards "Cold War in space" and "small ships", but am open to a variety of approaches if it all hangs together logically. One thing I would like to see more of is sophisticated missile-design rules,

Then it's Ve2 possibly even with the "build missiles as small vehicles" option. After that pickings get _thin _.

[Anthony]

Originally Posted by Michael Thayne

I tend towards "Cold War in space" and "small ships", but am open to a variety of approaches if it all hangs together logically. One thing I would like to see more of is sophisticated missile-design rules, since I don't see how you get a spacefaring society without also having some incredibly destructive missiles, thus making missiles very important to space combat. And if you want to boost point-defense to mitigate that, the implications should be applied consistently across the setting.

Functionally, a missile is just a small drone vehicle that you classify as expendable.

I would note that "good missiles" and "interesting space combat" are mostly incompatible; missile combat tends to devolve into "if you launch enough missiles to overwhelm point defense the target dies, otherwise you wasted your ammunition".

[Michael Thayne]

Originally Posted by Fred Brackin

Then it's Ve2 possibly even with the "build missiles as small vehicles" option. After that pickings get _thin _.

Sigh. You may be right. Possibly my reluctance to embrace Ve2 is because it's so easy to see some of the things you'd surely want to fix in VDS 4e. Sadly, I didn't get into GURPS until circa 2010, so I missed out on being able to be a part of that playtest. (I understand the playtesters are still occasionally getting mileage out of designing things going off the playtest draft.)

Originally Posted by Anthony

Functionally, a missile is just a small drone vehicle that you classify as expendable.

Sure. Though systems like GURPS Spaceships 4e don't support building drones as small as you'd like the missiles to be.

Originally Posted by Anthony

I would note that "good missiles" and "interesting space combat" are mostly incompatible; missile combat tends to devolve into "if you launch enough missiles to overwhelm point defense the target dies, otherwise you wasted your ammunition".

I don't think this is necessarily true. For example, the board game Attack Vector: Tactical has pretty interesting rules for kinetic weapons. My only issue with AV:T is that it doesn't have a ship design system.

[Anthony]

Originally Posted by Michael Thayne

I don't think this is necessarily true. For example, the board game Attack Vector: Tactical has pretty interesting rules for kinetic weapons. My only issue with AV:T is that it doesn't have a ship design system.

AV:T makes some extremely dubious assumptions about performance of kinetics (I haven't been in contact with Ken Burnside for quite a while now, but we used to both hang out on sfconsim-l), particularly in the amount of course correction he gives them. I know why he did it, "missiles always hit" isn't super interesting game play, but having performance worse than 20th century missiles isn't terribly convincing.