The State of (My) GURPS Vehicles

If you've been following my blog for awhile, you know that I have a vehicles systems that's an update of 3e Vehicles with 4e values and rules, where I can find them. My patrons have asked me to give an update on that system, and you can find the latest rules here (Available to any $1+ patron).

I also wanted to talk about my experience working with Vehicles throughout the past year to build the gear for Psi-Wars, what I think works, what I think doesn't, and my feelings in general on the Vehicles vs Spaceships debate.

Was it worth it? Yes!

So, the first question is "Has all of my work been worth it?" The answer is complicated, but the first half is "Definitely, yes."

I work as a programmer, and one thing that a lot of fellow coders like to comment on is misusing X to do Y, when you should just build Y to do Y, and I think that sort of thinking has helped Psi-Wars immensely.  Previously, I had used GURPS Spacehips to "fake" the space combat of Psi-Wars, but when you accept that what it really is are (space) ships fighitng (space) fighters, and build a system around that, everything falls into place nicely.  The Action Vehicular Combat system has, for me, been a godsend.  I find everything makes much more sense, and works pretty much the way someone would expect.

Of course, I'm here to talk about Vehicles, but that's key to this.  The problem with GURPS Spacehips is that it's built to deal with spaceships, and it turns out that beyond atmospheres, you should be measuring speeds in miles per second and distances in AU, and Star Wars and Space Opera just don't work like that.  They work more at "ground speeds and distances," and those require a ground based system and Spaceships is, at best, wonky when it comes to that.

The new vehicles system has allowed me to get very precise when I need to, to put guns that are "too big" on a vehicle, or guns that are "too small," and to fiddle with electronics or room design in very specific ways that Spaceships would never allow.

It's also not nearly as difficult as you might think. Sure, you need spreadsheets to make heads or tails of it, but you're here, right now, reading this on a computer, and chances are, you work with office software all the time. You can put together a basic spreadsheet.  Some stuff I have do is complicated, sure, but you can find ways around that and just do it by hand.  In the end, I really noticed I was using more and more complex rules to properly model my vehicles and sort of reverse engineering values out of various pyramid articles, so this system has acted to collate all of those little notes into one consistent place.

Was it worth it? No, not really.

On the other hand, I often feel a twinge of regret for leaving the Spaceships system.  The biggest revelation is that most of the stuff I do doesn't really matter.  For example, I often put a Link between multiple guns that are designed to fire together.  The guns, often huge blasters, will be $1,000,000 credits each, and the link itself will be $50.  When the complete vehicle is done, it'll be something like $498,001,155 or whatever, and I'll just round it up to $500,000,000 and whether I had noted a link or not literally doesn't matter.

I find this "doesn't really matter" applies to a lot of things, especially the larger vehicle.  Does it really matter exactly how many cabins or bunks a Dreadnought has?  Does it really matter the exact speed?  Speed is actually really interesting because, based on the Action rules, you have a logarithmic scale of speed, which means you need more and more of it to make a difference, so at the very high end, the difference between a vehicle that goes 1000 yards per second and a vehicle that goes 1500 yards per second is a difference of +/-1 on your rolls!  That's a feature, rather than a bug, for me, but it often means I shrug at minor differences in speed.

I find, in fact, that I begin to arbitrarily use values: a +1 Handling or HT here, a -1 Stability there.  Increasingly, I use my Vehicles system as a more "order of magnitude estimation" of what's possible and what's complete nonsense, and then set my stats based on that. I don't mean to say I make no use of the stats, or that the vehicles aren't close to the final designs; I am saying I fudge, and if you're going to fudge, why not use the Spaceships system?

I will note that Spaceships does modularity a lot better than Vehicles does.  One of the things I came across pretty early on in my vehicles design was the revelation that some players will want to "mod" their spaceships.  They don't want an X-wing, they want a special, unique version with a boosted force screens and a dodgy energy system that their Astromech has to pay constant attention to, which means you need to be able to remove some parts and replace them with others. Spaceships does this very well, because they're all just slots.  With GURPS Vehicles, though, it's a nightmare, so I've been experimenting with RedJack ships and modularity.  The hardest part is handling the speed: if you can keep all the weights and volume the same and not mess with motive thrust, then you can slot things in and out pretty much interchangeably.  But when you start leaving parts off, though, or adding more engines, you start needing a spreadsheet to recalculate everything, which is a hassle.

Also, since I designed my Vehicles system, a new Pyramid issue has come out that details how to convert handling and stability.  It's actually a great issue overall for creating your own vehicles, so if you want to ditch my system and just build your own, this is actually pretty good: "Describing Vehicles" in Pyramid #3/120.  I've not yet used it for my vehicle calculations, in part because some bits I disagree with, and others I just have't looked at in sufficient detail, and it would require revisiting a lot of other vehicles to make sure they were correct, but I may.  The main things I disagree with are how he assigns Handling and SR.  He's not wrong, mind you: eyeballing it is basically the way to go, but I chose to go with a more detailed system that I felt defensible for what I wanted (and it's also all over the map if you look at actual vehicles and their actual handling), so I've not bothered with it.  That's not to say you couldn't use it, though.

GURPS Vehicles vs Spaceships

So, should you use Spaceships or Vehicles?  I think it depends on what you're trying to do, but I would broadly say: Spaceships is a decent estimation tool, but it has some pretty glaring flaws.

The first is how it handles mass vs volume and how it scales. I've wanted to do a cross-post series with Worlds Beyond Earth who takes a deeper look into the flaws of Spaceships, but my numbers keep disagreeing with his, I don't want to start a blog fight, and I'm pretty sure if we sat down and worked out the numbers between us, the differences (and who was making the mistake) would emerge and both of our numbers would improve as a result, but I don't have the time for it right now; nonetheless, I do recommend you look at his series.

When it comes the mass/volume of things like super-science devices (which could be anything, so its guess is as good as yours), rooms, cargo space, hangars, and large-scale industrial equipment, it looks pretty spot on.  It also looks pretty good for large vehicles: my dreadnoughts look really close to Spaceship's dreadnoughts.

Energy usage is off, and I'm not sure why.  Spaceships seems to argue that, say, Fusion is about 2× as good as Fission, while Vehicles (and Ultra-Tech and most physics I've seen) suggests you're looking at more like 10×.

Armor is fine for mass (you can quibble about the values, especially what the material of each armor is made of, but my numbers say they look about right), but it's totally off for volume.  There's a fix for that, though; alternatively, you can skip the armor step, come up with the vehicle, and layer the armor atop it, but then you need to come up with your own mass vs thrust ratios to determine the final speed.

Electronics is totally off.  My experience again and again on equipment is that your sensors, ECM and computers take up basically no volume or mass budget of the vehicle, and they're often very critical and specific.  Spaceships treats them as a big, broad thing, with a few little minor elements suitable for space, but you don't get into the gritty details like you do in GURPS Vehicles and, as a result, I've been left pretty in the dark on quite a few gadgets and how to deal with them.  There is definitely no way that an ECM system would take up 3/20ths of a vehicle, or a sensor system unless you're talking a really small vehicle with a giant ECM or sensor system meant to cover a huge area, and Spaceships doesn't treat them like that. Cost is a much bigger deal. Frankly, when it comes to electronics, I think you're better of grabbing ultra-tech, taking its electronics, and just slotting them into a cargo slot and saying they're integrated with the rest of the vehicle, or just ignoring that altogether and adding the costs of those electronics to the vehicle.

Weapons are another element that I think are totally off.  I think they're ultimately just given arbitrary values that feel "gameable."  I did something similar with my Psi-Wars designs, and you end up in a similar situation of "photon torpedoes let fighters kill really big ships but have limited ammo, and blasters are only good against other fighters" but I have a lot more flexibility about the designs I put together.  This is double trouble, though, because we don't have a decent ballistic design system (though we have some larger missiles in some of the older Pyramid issues) and we don't have a decent energy conversion rate between Spaceships and the blaster design system; that said, I find I end up using power cells anyway and assume they recharge during down time, so you can just do the same for your Spaceships, skip the weapons from GURPS SS, design your own, and then add their mass to the ship.  You'll need some help if you want them to have turrets and stabilizers, etc, but at that point, you're better off with the full Vehicle design system anyway.  Honestly, weapons are where it goes wrong the most, especially on the very small scale.

So, would I do it all over again?  I think so, but I wouldn't throw Spaceships out completely.  I wouldn't mind seeing a revision that looked more carefully at power-requirements (and maybe provided some conversions, especially with power-cells), weapons (especially if we had a proper weapon design system), electronics (and some more details on how they worked, especially ECM) and armor, I think you'd have a perfect system, but I'm not sure how different that would look from a simpler vehicle design system anyway, so maybe we're left waiting, hoping, for the release of the new Vehicles system!