Thursday, October 31, 2019

Robot Design Revisited

Psi-Wars needs robots.  Star Wars has its droids, and cute sidekick robots and ominous kill-bots clutter up Pulp Space Opera.  They tell you that you're in a sci-fi world, and they occupy an interesting niche between tool and character, especially in pulp space opera.  They let us waive the complex technobabble by having a robot do it ("Reverse the polarity of the neutron flow" becomes "No, shut them ALL down!").

We have a few things that we need Psi-Wars robots to do.  They need, of course, to be trusted allies, someone our fighter ace counts on to keep his starfighter in tip-top shape, or someone our noble trusts with his agenda.  People will also want to play as one, because they've already been asking.  In both cases, we need to know the point totals involved.  Finally, people will want to buy robots, like picking up a hireling.  Sure, you can have that trusted Tech-bot fixing your starfighter, but if you don't care about your starfighter all that much and you don't need to be on a first name basis with your robot, won't any robot off the market do? In which case, how much money do you spend on your robot? So, we need to know a price for our robots.  If we're honest, we also need to know the weight and power-consumption of our robots too, at least in broad terms.

How to Build a Robot

The simplest thing we can do is just use the robots in Ultra-Tech.  They're pretty flexible and you can add and subtract a few gadgets, and this more-or-less works.  For earlier iterations this was fine, and it's how Iteration 3 worked, but if we're going to customize everything, we can do better.

We can also build them as racial templates.  We just decide what robots look like, because they're basically characters after all, and nobody demands we put every new racial template through a rigorous, secondary design process.  Even so, here we reach the crux of our problem: how do we go from point cost to dollar cost, weight and power-consumption?

Weight is easy to derive: divide their ST by 4, and then cube the quotient.  For power-consumption, we can make some guesses from the robots in Ultra-Tech.  We can do the same for cost too.  I carefully combed over all the robots in Ultra-Tech to get a sense of prices, and then created a system I called "Modular Robots."  The premise here was that a robot of a given size tends to cost X, and the more features you give it, and the more you remove, the more the price changes, and they seem to follow rough tiers.  And this basically works, and I suspect it's how a lot of robots were derived in GURPS Ultra-Tech, more or less, though I'm not convinced all of my results were correct.  For example, I rate the loss of speech pretty high when it comes to affecting the cost, but this is a guess because there aren't any mute robots in Ultra-Tech, and it's probably a wrong guess, because removing speakers and voice synthesis software at TL 10 probably amounts to saving a few buck, rather than halving the cost of the robot.

This was as far as I could go, though, because GURPS 4e is pretty fundamentally divorced from 3e about certain things.  For example, in 3e, ST was derived from the total power available to the robot, while in 4e, it comes from the mass of the robot. IQ and complexity have a totally new relationship, and how Ultra-Tech derives DX is a total mystery to me, but it's not derived in anyway similar to how Robots derives things.  So I closed the book on it. This was enough.


Reader Mwnrc asked me how I designed robots, and I gave him the above spiel.  This set off an entirely unexpected firestorm.  A surprising number of people had no idea how you derive HP from mass, or that this was a thing in GURPS (you can find it on page B558, page 10 of Pyramid #3/120, and it's in the very robot rules referenced by Mwnrc).  But then someone raised an interesting point:

"But Mailanka, the robot masses in UT vary."
What he means is that if you look at androids, their mass varies from as low as 50lbs for a TL 12 android, to as high as 250 lbs for any robot.  The Combat Android does this too.  None of the other robots that I looked at do, though: the tech-bot, the medical robot, and the war-bot all have fixed weights.  Even so, this was interesting.  Could it be that these were created using the robot design system that clearly doesn't work in 4e anymore?  Well, the least I could do is actually check.  So I ran some numbers. The following numbers look only at the Arm motors, the leg drivetrains, and fairly basic structure and with the computer brain added in.

TL7 TL 8 TL 9 TL 10 TL 11 TL12
0.3 0.2 0.015 0.1 0.075 0.05
80 60 40 30 20 15
6 4 3 2 1.5 1
2 Arm motors ST 14 3 7.8 5.2 0.39 2.6 1.95 1.3
Body ST assuming 200 lbs 250 23 17.25 11.5 8.625 5.75 4.3125
SA for human 30 180 120 90 60 45 30

210.8 142.45 101.89 71.225 52.7 35.6125
5 5 5 5 5 5

215.8 147.45 106.89 76.225 57.7 40.6125

Let me break down these results a little more clearly for you
  • In Ultra-Tech,  A TL 9 android is between 150 and 250 lbs; the above results show 107 lbs.
  • In Ultra-Tech,  A TL 10 android is between 100 and 250 lbs; the above results show 76 lbs.
  • In Ultra-Tech,  A TL 11 android is between 70 and 250 lbs; the above results show 58 lbs.
  • In Ultra-Tech,  A TL 12 android is between 50 and 250 lbs; the above results show 40 lbs.
Now, the values don't line up (though they do line up very nicely with the previous TL, ie a TL 11 robot is ~58 lbs in this while a TL 12 robot is down to 50 lbs), but we haven't touched on armor, communication systems, sculpting, or whatever else we'd like.  This is basically a back-of-the-envelope calculation and it shows the same basic progression.  In short, if you take a naked robot from 3e and translate him to 4e, the numbers line up pretty close.


So I did a little extra investigation.  It seems obvious to me that Ultra-Tech was heavily influenced by Transhuman Space and Reign of Steel, two of GURPS' more successful settings.  Surely those had major updates to their dollar cost and weights.  I checked in 3e, and found that 3e had explicit dollar costs and weight values for both series (I found it quite surprising in Reign of Steel, which looks explicitly built using the Robots book, and you can find the price of an Overlord chassis down to the penny).  This isn't relevant to us as economics fundamentally changed between editions except... the conversions don't list new prices or new weights.  They list them for alternate versions unique to 4e, but if you're using an Overlord or a Cyberdoll, then you're using the original version, only with an updated character template.  This means that GURPS 4e accepts robots built using GURPS 3e's robot design system as canon. Intersting.

Can you Convert Robots 3e to 4e?

A last experiment: let's just build an android in 3e and see what pops out.  Keeping in mind that an Android in 4e for TL 10 (where I tend to center my robots in Psi-Wars) are 100-250 lbs and $50,000, I came to 144 lbs and $63,000. That's... really not that far off.

Mwnrc had a system he was using which purports to convert robots from 3e to 4e.  You can get it here. When I ran those numbers, I cam eot a robot that weighed 101.75 and cost $45,370.  If you round that up, that's almost precisely the weight and cost of a TL 10 android.  Wow!

For me, the android is sacred.  What I want out of my design system is to essentially get the robots, especially the android, from first principles.  This gives me pretty spot on.  I could try some others to be sure, but this definitely gives me some hope.

Robots 4e Deep Dive

Let's take a closer look at this document, shall we?

Robot Brains: Personally, you should just use the computers from Ultra-Tech, as it clearly does, and that's what I'll be doing, but this more or less does the same.  The main difference is that it reduces weight of the computer at higher TLs, but I'm not sure why it does that.  It seems to be some sort of compromise between 3e and 4e.  I won't be doing that.

Sensors and Communicators: These are a major sticking point for me for customizing the robots from Ultra-Tech.  How much does removing a voice box save you? What if we drop a robot down to a single camera eye? What are the savings?  This document seems to have derived some cost and some weight and I have no real way of telling if they're right or wrong, except with the radios and such.  I will note that this document gives the radio range as 100 miles, while the robots in Ultra-Tech are priced at 10 miles, though I will also note that Psi-Wars communicators are much better than bog standard radios, so that might need to be something addressed.  In any case, this gives me basic sensors and voice boxes and his prices and weights are as good as anyone else's, and given how accurate his prices ending up being, I'll stick with it.

Arm Motors: Look to be derived directly from 3e, which looks fine.

Weapons and Accessories: The document seems to suggest you just take UT gadgets and slot them in.  This seems exactly right to me.  It's what I'd do.

Body: We skip drive train and go straight to structure, sculpting and armor.  He does some weird things with volume and surface area, but it ultimately derives from size modifier, which is a good choice.  I originally objected to the fact that a sphere has way more surface area for the same size modifier as a human, but that's because a person's size modifier is very large for their surface area, rather than the other way around, so fair enough.  That said, I'd rather just use the volume-based rules of Vehicles, but it doesn't matter: you just need to derive A surface area.

From there, the rest looks fine.  I think I'd substitute psi-wars armors in place of generic armor, but that's to be expected.

Drivetrain: Finally we reach propulsion; interesting choice to put it at the end, but I understand the logic.  You need to know the final weight for this to work, and it can create a feedback loop if you do it too early, so it makes sense to wait until the end.  He does some fancy math that let's you essentially just focus on your move and your weight and derive the weight and cost from it, and it seems to work.  My only objection is he asks you to first figure out the power requirements, but gives no instructions on how to do so.  I just assumed the same power requirements as an android and moved on.  Still, a red mark there.  In general, the power requirement rules are kind of strange, but I get it.  What can you do without a KW value?

The Stats
ST and HP work as expected, though it doesn't actually give "correct" results as far as UT is concerned: my android ended up at Arm ST 14 and HP 20, but also body ST 20, which doesn't line up with HT.  However, we can ignore the body ST idea and just say arm ST is ST if we want, while "body ST" represents HP.

The logic of GURPS Robots and this design sheet (and GURPS vehicles) is that if you can move X amount of lbs at Speed Y, then you have Z body strength, period.  You can't really have a twenty ton robot with the ability to race around at sonic speeds with an ST of 1; it's ST 135.  Ultra-Tech doesn't seem to agree, so the choice is: who do you trust here? 

DX is also interesting.  This document follows GURPS Robots and gives DX as an aspect of computer complexity.  This creates a hard connection between DX and IQ, however.  If you're IQ 10, you have a complexity of 8, which means you have a DX of 12, period.  There's now way to have low DX on a high IQ robot or vice versa.  Ultra-Tech definitely seems to disagree with this.

There's some interesting logic here too. What is DX? In one sense, it's your ability to process the outside world and carefully calibrate your actions to create the effects that you want. This means accurately modeling the world, your position in it and what will happen when you do a thing: hitting someone with a bullet, for example, involves calculating trajectories extremely well; that we do it unconsciously and transfer that calculation accurately to our bodies is why we call it "DX" rather than "IQ," but in this sense, the complexity of a computer as basis for DX makes sense: a smarter computer calculates trajectories better and is thus more accurate.

On the other hand, the chassis matters to.  DX also covers reaction time, balance, the ability to move one's body with a great deal of precision and the flexibility to achieve the position you need to. If you have one of those weird, stiff robot arms with metallic grippers, it doesn't matter how smart the machine is because it cannot translate those calculations to its body correctly, as it lacks the body to carry them out.  Reaction time seems to be mainly a complexity thing in Ultra-Tech too, at least if you want Enhanced Time Sense, but that's not quite the same as Basic Speed: knowing you need to draw your sword instantly isn't the same as being able to draw your sword instantly.  However, balance, flexibility and manual dexterity tend to be covered by advantages, and Ultra-Tech seems to use Advantages to cover them: I see a lot of Manual Dexterity in Ultra-Tech robots, for example.

So I suspect we need something like how GURPS Robots handles DX, but perhaps lower, perhaps (Complexity/2)+6 with an option of buying a "reflex booster" like they have in GURPS Robots.  Incidentally, if you want to see the hard relationship between IQ and DX in this work, see below:

Complexity DX IQ
1 8 NA
2 9 NA
3 9 0
4 10 2
5 10 4
6 11 6
7 11 8
8 12 10
9 12 12
10 13 14
11 13 16
12 14 18
13 14 20

You can see why I'm a little iffy on the DX 12; to have human level intellect, according to these rules, you must start to have high DX; only sub-human-average IQ robots have human average DX.

IQ is based on complexity, fitting Ultra-Tech.  That's fine.

HT is based on a complex equation that amounts to: the heavier your frame and the lighter your robot, the better your ST.  I think I would replace this more with guidelines.  Stronger frames means more HT, and more system redundancy (like ruggedized electronics systems and hardened brains) give higher HT.  Interestingly, robots tend to be built out of various components which can be more rugged than other components.  What do you do when hit with a surging attack when you have a Hardened Computer, but a Cheap set of power-cells except your brain has a backup battery that's also hardened? Do you roll one HT for consciousness and another for your electrical system? Do you roll a third system if your structure is made of average components to see if damage destroyed you?  I think in the end a sort of "Combine various elements together broadly."  Focusing on structure isn't too bad an idea, though: expensive structures probably have more resilient housing for its electronics and better interconnections, which matters: who cares if all your components are still working if they're scattered to the wind because the balsa wood and bailing wire holding them together failed? On the other hand, the quality of those components matter too, so it's a balancing act and I tend to favor more of "rough guidelines" than "hard values" for HT.

Do we need a Design System?

I've been building robots for awhile already, and I found myself rather hostile to shifting to a design system, because it's much easier to just put character traits together, and it covers 90% of what people actually care about.  With vehicles, I often found that when I designed a vehicle, I had to go through a lot of work to make certain values "line up," and that would be a nightmare if I was trying to create vehicles-as-characters.

With Robots, as I explored it more carefully, I quickly found that I could probably just design the character and then find out what the cost and weight would be.  I have no good guidelines on power requirements, but I think people will just accept whatever values I use, as long as they feel close to right.  The other interesting thing about a design system is that interesting cost/benefits start to pop out, like surface sensors are stupidly expensive, especially on larger robots.  Does a robot tank really need surface sensors?  Going through a design system might make your robots feel "cohesive" and "logical" in the sense that the design makes sense, and thus it feels like a robot, rather than just another character with robot-like traits.

I think having seen both of these in action and worked with them a bit, I'm willing to work with a slightly updated version of the 4e design set. Most of the changes I'll make will reflect Psi-Wars peculiarities or my own specific opinions on things, rather than failings of the 4e Robots Design system.

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