The World Builder's Handbook - It Is Here!
- Thread starter MongooseMatt
- Start date
Geir
Emperor Mongoose
You mean the Sudarsky classification? It seems a bit provisional to me (okay, and so is just about everything about exoplanet and certainly about their atmospheres and life forms) but at least it's out there. Gas giant details definitely goes on the list of potential articles. I'm not the greatest fan of the Companion's approach to skimming, mainly because it seems overly burdensome unless it's the focus of an adventure (okay I put it straight into one of those JTAS Patron encounters that got pulled from the Spinward Extents, so it's not like I hate it - but for 'background use' a single roll of success and another for duration seems about all you'd want to do in most circumstances), but adding general rules about gravity, radiation, and temperature issues of specific gas giant types or properties would be a good idea.
I just checked the wiki article on Sudarsky's and it doesn't look like it covers ice giants, so it might not be an ideal method of covering the spectrum of everything from a gas dwarf to a superjovian, but its a start.
Geir
Emperor Mongoose
I'd love to do a proper ecosystem book (Climates and Critters?), but I think that would be behind three others that I've sort of committed to do... and really need to get cracking on...@Geir I have to say, I love this material so much that I have ordered a new 12" tablet just so that I can read the pdf easily while waiting for my hardcopy. I look forward to full books on social, economic and religious materials with the same level of depth
PeterDebney
Banded Mongoose
I have always loved the world-building aspects of Traveller, whether in the core rules or in the original Scout handbook. This new supplement has taken those and more than filled in all the gaps. I am really looking forward to getting my hands on the hard copy, because PDFs are just not as useful.
Speaking of which, I have noted a couple of errors:
When viewing the latest version, at least in the iPhone version of Acrobat, the index is mostly broken. Only a few links go to actual pages:
Secondly, the example for terrestrial planets is confused/ing. The DM is -1, which means that DM+D3-1 should give numbers from -1 to +1: +2 should not be possible. Or have I misread it?
Speaking of which, I have noted a couple of errors:
When viewing the latest version, at least in the iPhone version of Acrobat, the index is mostly broken. Only a few links go to actual pages:
Secondly, the example for terrestrial planets is confused/ing. The DM is -1, which means that DM+D3-1 should give numbers from -1 to +1: +2 should not be possible. Or have I misread it?
PeterDebney
Banded Mongoose
Yes, but there is also the DM of -1
Epabaa
Mongoose
For the post stellar object that is part of the system
Geir
Emperor Mongoose
(coffee not working, but I'll try to answer correctly)
So the DM for post stellar stellar was applied to the first roll (a 12 -2 - the post stellar DM(1) = 9 ) and the D3-1 roll came up as 3-1 = 2 and 9 +2 =11. The original language was a little unclear, so in the updated file it makes it clear that at this point we just add D3-1.
Original download:
New download:
(argh... if it wasn't for the little red underling I wouldn't be able to type this at all - I think the caffeine leached out of the coffee pod)
Geir
Emperor Mongoose
Second cup of coffee seems to be working better.
So why the weirdness in the terrestrial planets calculation, you might ask?
Well even if you don't care, here it is:
I had two goals, one was to match the T5 and therefore Travellermap requirement of having at least 2 and not more than 12 "other worlds", but with the Mainworld being counted separately, unless the Mainworld is a moon, you need to have at least 3 things that aren't gas giants or asteroid belts, so that sets the (always safe) lower limit at 3. The upper limit is I guess technically 13, since T5 determines these with a straight 2D, and then adds, potentially but not always, 1 for the Terrestrial aka 'other worlds' plus the Mainworld. So to be safe (avoiding any out-of-bounds result), I stuck with 12 as the upper limit because it would never violate the condition. But, for my second goal of trying to be realistic, I thought 7 was way too many terrestrial planets on average, especially in systems where a star may have gone through a red giant phase and eaten many of its children (hence that DM-1 for post-stellar objects). I wanted 2D-2 with a mean (and mode and average in this case) of 5, but of course that can go below 3 and never gets higher than 10. So, I decided to keep the 2D-2 bell curve, but mess with the boundary conditions (see previous post). The probability map looks like this:
So I get my curve maxing at 5 (and probably a little less with dead stars in the mix). The point (if there is one) of this is to point out that the number of terrestrial planets ends up being something that conforms to the game parameters, not necessarily to 'reality'. If the WBH was game system agnostic, it would likely have been done differently, without trying to jam a result into a pre-defined box. But for Traveller, this works fine, and hopefully for reality it's not too implausible.
So why the weirdness in the terrestrial planets calculation, you might ask?
Well even if you don't care, here it is:
I had two goals, one was to match the T5 and therefore Travellermap requirement of having at least 2 and not more than 12 "other worlds", but with the Mainworld being counted separately, unless the Mainworld is a moon, you need to have at least 3 things that aren't gas giants or asteroid belts, so that sets the (always safe) lower limit at 3. The upper limit is I guess technically 13, since T5 determines these with a straight 2D, and then adds, potentially but not always, 1 for the Terrestrial aka 'other worlds' plus the Mainworld. So to be safe (avoiding any out-of-bounds result), I stuck with 12 as the upper limit because it would never violate the condition. But, for my second goal of trying to be realistic, I thought 7 was way too many terrestrial planets on average, especially in systems where a star may have gone through a red giant phase and eaten many of its children (hence that DM-1 for post-stellar objects). I wanted 2D-2 with a mean (and mode and average in this case) of 5, but of course that can go below 3 and never gets higher than 10. So, I decided to keep the 2D-2 bell curve, but mess with the boundary conditions (see previous post). The probability map looks like this:
So I get my curve maxing at 5 (and probably a little less with dead stars in the mix). The point (if there is one) of this is to point out that the number of terrestrial planets ends up being something that conforms to the game parameters, not necessarily to 'reality'. If the WBH was game system agnostic, it would likely have been done differently, without trying to jam a result into a pre-defined box. But for Traveller, this works fine, and hopefully for reality it's not too implausible.
@Geir So, I'm going through the book trying to automate everything (huge project, I know), and I'm stuck on calculating available orbit numbers in multi-star systems. The procedure starts with this:
which implies that the MAO of each star should be calculated from the table. So far so good. But then immediately after it says this:
Which implies the minimum is .5 + eccentricity. It would make more sense for me to be MAO from the table + 0.5 + eccentricity, is that what's intended? It also raises questions in systems with multiple very large stars. Twinned F5 Ia stars take up a lot of space!
Additionally, earlier in the book you assign stellar orbit#'s with this table:
But that makes no consideration of the MAO which at its most extreme from the table could be 7.8, wiping out the entire Close range, let alone the companion. Do the orbit #'s start from the surface not the center of the primary?
Hopefully all that made sense lol, just trying to figure this sucker out. I love the book as a whole!
which implies that the MAO of each star should be calculated from the table. So far so good. But then immediately after it says this:
Which implies the minimum is .5 + eccentricity. It would make more sense for me to be MAO from the table + 0.5 + eccentricity, is that what's intended? It also raises questions in systems with multiple very large stars. Twinned F5 Ia stars take up a lot of space!
Additionally, earlier in the book you assign stellar orbit#'s with this table:
But that makes no consideration of the MAO which at its most extreme from the table could be 7.8, wiping out the entire Close range, let alone the companion. Do the orbit #'s start from the surface not the center of the primary?
Hopefully all that made sense lol, just trying to figure this sucker out. I love the book as a whole!
Geir
Emperor Mongoose
Oh yeah, took me more than a month to spreadsheet it properly - dissecting strings in a cell without macros was a real headscratcher for a few days - hopefully you're doing it in an actual programming language.
It doesn't say that, but that's a really good idea for bigger stars. I have, honestly, a lazy reason for not wanting to make that change globally in that all the example text would need close examination and updating. And there would be carry-on effects for binary secondary star pairs disrupting orbits... so a bunch of text and calculations to fix for a .02 orbit effect.
Keep in mind that anything big enough to cause actual problems, like the F5 Ia twins mentioned, would follow the Primordial Star rules in Special Circumstances when it comes to making their planets. And they would be rare, like a handful a sector.
So, trying not to completely trash the 11 rules starting on page 38... rule 2 is already fairly long, but adding a sentence in the middle, right before 'Optionally':
For stars with an MAO of greater than 0.2 add the MAO of the larger star to the range of unavailable orbits.
And then for rule 5 (page 39), At the end add:
If a secondary star has an MAO of greater 0.2, add its MAO to the exclusion zone around the primary star.
That's pretty much a straight T5 port, but I see your point here too. And we can't refer to MAO this early, since its' 'facts not in evidence' or some such. Okay, then, page 23:
Yes. Thanks. I may have glazed on those cases in testing, since my mind went to: nasty, don't want to go to a system like that - all primordial and hard to jump to - pick a cool (temperature-wise) planetoid belt for the mainworld and move on. But a graphical view would have showed the problem.
I think the above three changes will cover 99% of the big star cases without disrupting the flow (or breaking the example).
(Well, maybe not in the biggest Class III in multi-star systems, but you could force your code to exclude objects inside of stars... although there are such things as contact binaries, and there might actually be 'survivor' planets in the rarefied atmospheres of Class IIIs - I think they found one such (former) candidate around a white dwarf, though it probably just migrated from an interaction with an undetected body.)
edit: table updated to match what I put in the feedback link (so it's now correct in both, hoping that doesn't cause confusion)
Last edited:
Question: by definition, about 80% of a belt's population orbits within its main span, but if you use the significant body orbit # generation procedure on page 74:
then only about 2/3 of the significant bodies will have orbit #s that fall within the main span. Is there a physical reason for this, or is this a design compromise to simplify orbit determination?
then only about 2/3 of the significant bodies will have orbit #s that fall within the main span. Is there a physical reason for this, or is this a design compromise to simplify orbit determination?
Geir
Emperor Mongoose
Ok, I think I follow: any result greater than +/- 2 on the 2D-7 would be outside the span, because the span is half above and half below, so yes, that is 1/3 outside.
I think I actually didn't think it entirely through (thinking that only +/- 5 would violate the span - which actually stuffs over 94% in)... so,
The above formula on p. 74:
The denominator should be 8, not 4.
Which makes for a tighter, not looser range, with the statement: Additional 10% variance to the span may be appropriate to add
pushing half the '3's and '11's outside the range, getting us to 88.8% of the significant bodies inside the span, which was my intent.
And on p. 75 for the examples, it should read (changes in bold):
No attempt is made to determine orbits for these
bodies at this time but for Aab PI bodies it would be
2.7 + (2D-7) × 0.25÷8 and for C PI it would be 1.4 +
(2D-7) × 0.3÷8.
I'll link the feedback thread back to this answer.
Thanks so much for the detailed response. I think your proposals make a lot of sense, and I'll follow through on them. Again, it's a wonderful resource for people who love this sort of thing, keep up the great work.
Geir
Emperor Mongoose
Thanks. As I think about it more, there's still a problem with your twin supergiant scenario if they are companions. I need to write an exception for giant star companions to push them out to something like 1D x MAO... but once I word that right I'll stick it in the feedback thread to make Bella's life easier.
Demon Samurai
Banded Mongoose
I am so happy that I've put this thought into your mind (if it wasn't already there). Loving the WBH.
Geir
Emperor Mongoose
Thanks! I'm really glad the WBH is turning out to be a strong seller. I know how much I wanted something like this, but that didn't mean that others would be as interested.
(But be careful putting thoughts in my mind. They often get lost, distorted, spindled, or mutilated. Spindled. Don't own a spindle, especially the kind you impale paper onto... oh, yeah, tangents, that's another problem with my mind.)
Geir
Emperor Mongoose
If there is another set of JTAS books in the future, I could do an article in each. Already have three topics scribbled down: Trace atmospheres, variable stars (including flares), and gas giant types.
Seffix
Emperor Mongoose
First, I certainly hope there are more JTASes. That said, I would prefer these articles (and Oort clouds, Wolf Rayet stars (the nearest is probably less than 10 sectors away...), and so on in a common volume for easier reference.
Dalton Calford
Banded Mongoose
It would be good to do an expansion of the "cubic parsec" concept - the one issue I have with the current WBH is the comment about a single system within the parsec. You could easily fit more into an volume of (3.26 by 3.26 by 3.26ly). Firefly/Serenity works within such a configuration.
