Space 4e System Generation
 

What do people think of the new system generation rules in Space 4e?

I rolled up a system this morning, although it seems to my (limited) knowledge more scientifically accurate than most other systems I've run into. I only defined physical parameters for the system (an M7 Ve star with 4 gas giants (one epistellar), no terrestrial planets, no asteriods and 3 moons bigger than moonlets), and not social parameters yet, but those actually look quite easy. The only problems that I ran into was the headache I got while trying to generate planetary diameters for the moons (I think I got it right eventually), and trying to get the planetary orbits right. Up until working out the diameters I was stunned at how much simpler the system was compared to First In, but still more than adequate for gaming purposes. I think once I get that down I'll be in better shape.

I might try a few more tonight once (I have a red dwarf binary, another flare star, and G1 V/White Dwarf pair in the pipeline...) and see if I can get a habitable planet or more variation.

What are other peoples experiences? I'm curious as to what other people are doing with this part of the book...

Re: Space 4e System Generation
 

I'm going to turn it into an Excel spreadsheet in an attempt to ease my throbbing brain. It's an awful lot of detail...

When I was cooking up my first set of aliens, they were basically "people in funny suits". With the environmental/biological modifiers for social interaction, my next set of aliens will work MUCH better.

Re: Space 4e System Generation
 

I use Excel to chug through the formulae, but my Excel-fu isn't strong enough to really make a general purpose template (or whatever they're called...) There are so many variables that I just find it easier enter the values on my own.

I hadn't though of the alien generation stuff yet. I had planned on cribbing aliens from Traveller, Uplift and GURPS Aliens, but perhaps I will try and cook up some unspeakable strangnesses myself...

Re: Space 4e System Generation
 

I like it. I rolled up several systems. I made an excerpt with just the tables, and rearranged them somewhat. For example I integrated the table where one rolls for mass with the table which gives data for the mass. I also split it into three seperate parts: Star & System, Gas Giants and Moons, Terrestrials and Moons. That way it becomes a lot more handy.

I believe the Brown Dwarfs have a mass that is too large by a factor of 10, the given values would put them in the same range as K- and M-stars.

Re: Space 4e System Generation
 

I wondered about that too.

Re: Space 4e System Generation
 

I've instituted a "house rule" of sorts for placing planetary orbits in order to simplify the math: any time that orbital position and blackbody temperature interact, I determine orbital position relative to the Snow Line instead of using the star's luminosity. The relationship that I use is:

(orbital radius / snow line radius) = (126 Kelvins / blackbody temperature) squared.

(Why 126 Kelvins? Because that's the temperature that I get when I plug the Snow Line radius into the formula in step 25. I'm seriously considering using 125 Kelvins instead, since it's a nicer number and I doubt that one Kelvin out of 126 will trash the system.)

Step 21, placing a predesigned world: R = (126/B)^2 * Rs
Step 25, blackbody temperature: B = 126 / square root of (R / Rs)
(In both cases, Rs = snow line radius.)

World Type Assignment Table: I pencilled in a column giving appropriate orbital radii as percentages of the snow line radius.

I've replaced the luminosity-based Inner Limit with 0.2% of the Snow Line radius. It requires computing the Snow Line before computing the Inner Limit; but that's not a major problem IMHO.

I'm also inclined to say that not even epistellar gas giants can exist inside the luminosity-based inner limit. Incidently, this also places a hard upper limit of planetary blackbody temperatures: 2800 Kelvins.

I'm looking into guidelines for climate variations based on day vs. night, using the Tide-locked world rules as limits. My problem lies in figuring out how long a day can be before the limits are hit. I'm also interested in computing lattitude-based variations; while I know that there ought to be a simple formula for this, I don't know what it would be.

Re: Space 4e System Generation
 

I have some stuff which I copied somewhere, maybe Space 2e:

Average Temperature is up to two levels hotter at the equator, up to four levels colder at the poles.
Summers are one level hotter per 18° axial tilt, winters are one level colder per 12 ° axial tilt, but effects are felt only starting from the poles, with larger tilts affecting larger areas.
Days are one level warmer and nights are one level colder per 40 hours rotation, rounded up, up to a maximum of 5 levels.
Oceans damp nearby variations one level.

(Levels are the temperature bands defining "Cool" or "Tropical".)

2e also had rules to determine a Weather Factor, which influences how massive weather changes are.

Re: Space 4e System Generation
 

I had noticed that didn't seem right either, but I wasn't sure if it was a consistantly misplaced decimal point or something else. Hopefully errata will be forthcoming.

Re: Space 4e System Generation
 

I'm not sure about that -- haven't large gas giants been detected very close to thier primaries in other star systems? I think they can survive there if they formed further out and have sufficient mass to keep their atmosphere despite the increased heating, but I'm decidedly not an astrophysicist.

I have largely the same stuff from First In, so I'll just but a couple additional notes in:

Adding to what Pomphis wrote, for latitude based variation, the planets "average" climate zone should be in hex rows 4-5 (on the old icosahedral map), while rows 2-3 will be one categories warmer, while the equator will be two categories warmer. Repeat the same sequence heading towards the poles (6-7 one cooler, 8-9 two cooler, 10-11 three cooler, and 12-13 four cooler). While the book (First In) doesn't say either way, I think that this requires a substantial atmosphere to work and distribute the heat evenly. Of course, if there isn't an atmosphere, the PCs will probably have problems other than the temperature...

For seasonal variation, the only thing that I would add is, according to First In, axial tilts of 40 degrees or more will affect temperature to some degree all the way down the equator, while planets with 25 degrees of tilt would have "full seasonal effects" in rows 7-13, but not so much below that. I found that with First In I generated a lot of planets with high axial tilts, which would probably cause all sorts of headaches for settlers trying to do any sort of agriculture.

Re: Space 4e System Generation
 

Has anyone else noticed that the text on page 84 says to divide the average temperature by the black body correction makes no sense?

Doing it that way makes high greenhouse numbers COOL the planet.
A pretty glaring error.

Can someone confirm this just in case I've lost my mind, please.

Re: Space 4e System Generation
 

It makes sense. To determine whether environmental factors such as albedo or the greenhouse effect has cooled the world or warmed it, compare the blackbody temperature to the climate: if the climate is warmer than blackbody, then the environmental factors have warmed the world; if it is lower, then they have cooled it. Since dividing the climate by a greenhouse-dominated blackbody correction factor results in a blackbody temperature cooler than the climate, that means that the greenhouse effect has warmed the world.

Cooler blackbody temperatures equate to more distance from the sun; so what this calculation really means is that the planet has the listed climate, despite being too far from the sun to manage it without the greenhouse effect.

Personally, I postpone everything involving the blackbody temperature until Step 21 (Placing a Pre-Designed World; determine the Blackbody Correction, and divide the climate by it to get the temperature to use when placing the orbit) or Step 28 (determine the Blackbody Correction and multiply by the blackbody temperature by it to get the world's climate) - both of which are in the Advanced Worldbuilding chapter. You simply don't need the blackbody temperature for Basic Worldbuilding. Had I been in the playtest, I would have recommended moving the blackbody calculations into Step 28, and having Step 21 include a forward reference to them.

Re: Space 4e System Generation
 

But I start with the blackbody number, then try to find the actual surface temperature, or correction, as it says. This makes all greenhouse planets cooler.

Ohhhhh, waitaminute. I thought that the correction number was how to adjust the blackbody temperature arrived at based on AU distance. Otherwise am I just to guess at real surface temperatures?

Or should I continue to multiply by the correction since I started from the opposite end as expected?

Re: Space 4e System Generation
 

The correction factor is the ratio between the blackbody temperature and the climate. In Step 5, you start with the climate (that's what page 83 is all about), and you derive the blackbody temperature from it (page 84). In Step 28, you start with the blackbody temperature and derive the climate from it.

This is why I would have moved the concept of blackbody from Basic Worldbuilding's Step 5 to Advanced Worldbuilding's Step 28; you never use it in Basic Worldbuilding for anything. It only gets used in Advanced Worldbuilding.

Re: Space 4e System Generation
 

I am being deliberately provocative now but:

I was playing with the thought of buying GURPS Space, but somehow I could not find a good reason how I would utilize a System Generation Mechanic.
In most of the games I play the star system is flavor for the story.. some sugartoppings if you will. Nobody I ever played with (and there were a bunch of physicists among them) ever complained about things like: this system could never have a brown dwarf.. or .. the gravity of this planet has to be different etc. Not to even begin speaking about preparation time for something like this which is basically a background element (somewhat similar to the argument brought why spaceships are not in that book).

How do you utilize this in a game context? Isn't it somewhat like worrying: What kind of grass grows in the Orcish Swamps of my fantasy world?

Re: Space 4e System Generation
 

Oh fer cripes sake. Now that you point it out, it's obvious. I don't know how I overlooked that.
I certainly agree that its placement makes it far to easy to missinterpret and screw up.

Re: Space 4e System Generation
 

It can be, depending on whether or not you use it excessively. (What "excessive" means is an open question.)

However: even if you don't use the particular mechanics of the design sequence, it pays to at least look over the steps when envisioning a world. In particular, the Basic Worldbuilding chapter focuses on the environment that the PCs will find themselves in: atmosphere, climate, and surface gravity play the most prominent roles, with "wet" vs. "dry" playing an important backup role; and unless your group has no problem with the Firefly effect (where every world bears a suspicious resemblance to every other world), keeping these factors in mind can be a big help.

Another major use is the classification scheme given: the breakdown of worlds into Garden, Barren, and Hostile is itself a useful pidgeonholing of concepts, as is Tiny/Small/Medium/Large; and the full set of World Types can provide a basis for an in-setting classification scheme (such as Star Trek's famous "Class M world" ("Standard (Garden)" World Type).

In terms of the Social Parameters, I'll admit that population itself tends to be about as meaningless as a concept can be when it comes to roleplaying; population pressure, OTOH... And the other social parameters can be quite useful.

Besides: consider the hue and cry that arose when it was announced that GURPS Space wasn't going to have a starship design system. Can you imagine how much worse it would have been if they had left out worldbuilding as well? :)

Re: Space 4e System Generation
 

Actually it depends on the type of GM you are. I am the type who will use this. I was thinking of running a space exploration game, which this sort of detail is important. I think the fact so many people are interested in it kind of shows there are quite a few people interested.

As far as the time it takes, you see people are already looking at creating spreadsheets and I was thinking what a nice little C# program this would be. You have to understand there are a lot of gearheads and some non gearheads that might use it. I have files and files of stuff I reuse so it is never really used once and thrown away. For example I have probably 120 spacecraft I have created for Gurps Traveller, my players know them well enough they can probably name 40 of them off the top of their head.

Basically what I am saying it depends on the type of GM you are. Like the difference between prepers and wingers.

Vesper

Re: Space 4e System Generation
 

I also use it outside of games. That´s why I made excerpts of the relevant tables. That way I can design systems during otherwise boring meetings without raised eyebrows. If somebody has some papers, and sometimes writes something down, nobody is bothered. Much more discreet than reading a newspaper for example.

Re: Space 4e System Generation
 

I will have to remember that for my next meeting. I had a guy who use to work with me that use to create his own generators for his games. He said well management looks and sees visual studio open and assumes he is hard at work. The funny part is he still use to get as much real work done as two other developers

Vesper

Re: Space 4e System Generation
 

I noticed that, too. I checked some sources and they all seem to agree that a brown dwarf should mass about 10 to 80 Jupiter masses (i.e., about .01 to .08 solar masses). I'm going to treat it as a typo (i.e., treat the range in the book as .0015 to .07 solar masses, not .15 to .7 solar masses). Hopefully, there will be an official errata notice eventually.

Mark

Re: Space 4e System Generation
 

How's it going? I look forward to playing with it. :)

Re: Space 4e System Generation
 

I find this is going to be extremely helpful with the white dwarf system I'm currently working on. I mean I know they have a stated luminosity of .001, but there have got to be exceptions, and I like to do the math to see what happens.