World Builder's Handbook - Suggestions and opinions welcome

[MasterGwydion]

Tidal forces... That took a lot longer than I thought and hurt my brain more than I wanted.
Have to balance realism with level of effort and complexity and the ability to roll 2D and get an answer.

So there are three effects of tidal forces:
Tidal lock - that's the one we think about with regards to red dwarf worlds and moons of gas giants. That I can do as a table with a ton of DMs.
Tides - That's what happens when you're not locked and the water (or whatever) sloshes around the world. Three possible sources: the primary on the world, the moon on a world, and moons on one another. Formulas for each.
Tidal heating - Think Io and Enceladus - they're locked, but because their orbits aren't circular they still experience tidal forces that deform the surface and cause seismic stress. And causes mental stress:

From the wikipedia article on tidal heating:

... [the constant] represents the imaginary portion of the second-order Love number which measures the efficiency at which the satellite dissipates tidal energy into frictional heat.

Yeah, thanks for that.

I kludged together something good enough to be workable for those who care to delve into that detail. The kludged formula gives a result of 101 for Io, 11 for Enceladus, and 0.017 for Luna - good enough. It only actual matters when the satellite is in a resonance orbit with another satellite and that factor prevents circularization of the orbit. If eccentricity drops to zero, so does the tidal heating effect. And that ends the Science lesson for today.

Ouch! Thanks for the effort man. That made My head hurt just reading your post...lol...

 

[gilthy]

Very interesting (and interested ).

I'm a long time player, so (somewhere) are LBB-6 Scouts, DGP's Grand Survey and Grand Census, the MT World Builder's Handbook and the TNE World Tamer's Handbook.

I can also recommend to read (or browse) through the Mindjammer Traveller book, which has a more detailed (and modern) look on generating systems and worlds, while providing info on how to translate that to a more canonical Traveller UWP.

The MegaTraveller sourcebook Hard Times has info on how to the Rebellion and the Hard Times following it have an effect on UWPs.

 

[MasterGwydion]

Very interesting (and interested ).

I'm a long time player, so (somewhere) are LBB-6 Scouts, DGP's Grand Survey and Grand Census, the MT World Builder's Handbook and the TNE World Tamer's Handbook.

I can also recommend to read (or browse) through the Mindjammer Traveller book, which has a more detailed (and modern) look on generating systems and worlds, while providing info on how to translate that to a more canonical Traveller UWP.

The MegaTraveller sourcebook Hard Times has info on how to the Rebellion and the Hard Times following it have an effect on UWPs.

Nice list of references! Now I am jealous that I don't have most of those books...

 

[Geir]

Very interesting (and interested ).

I'm a long time player, so (somewhere) are LBB-6 Scouts, DGP's Grand Survey and Grand Census, the MT World Builder's Handbook and the TNE World Tamer's Handbook.

I can also recommend to read (or browse) through the Mindjammer Traveller book, which has a more detailed (and modern) look on generating systems and worlds, while providing info on how to translate that to a more canonical Traveller UWP.

The MegaTraveller sourcebook Hard Times has info on how to the Rebellion and the Hard Times following it have an effect on UWPs.

Thanks for the list.
I don't have Mindjammer, but all the rest are in a pile next to my desk right now. Okay, Hard Times isn't; I have it somewhere, but for these purposes, it's not necessary. Though if you remember where someone wrote the guidelines for reverting 1105 data to Milleu 0, then I would be interested. I'm pretty sure I didn't hallucinate it, but I can't recall where it was... (and don't talk to me about the T4 First survey: Vland: B967344-A 220 ? - come on, where the heck did all the people go?)

 

[AndrewW]

(and don't talk to me about the T4 First survey: Vland: B967344-A 220 ? - come on, where the heck did all the people go?)

They where eaten by a grue.

 

[Lurking Grue]

(and don't talk to me about the T4 First survey: Vland: B967344-A 220 ? - come on, where the heck did all the people go?)

They where eaten by a grue.

Hey!! I resent that! It is not even pitch black on Vland... :lol:

 

[gilthy]

Thanks for the list.
I don't have Mindjammer, but all the rest are in a pile next to my desk right now. Okay, Hard Times isn't; I have it somewhere, but for these purposes, it's not necessary. Though if you remember where someone wrote the guidelines for reverting 1105 data to Milleu 0, then I would be interested. I'm pretty sure I didn't hallucinate it, but I can't recall where it was... (and don't talk to me about the T4 First survey: Vland: B967344-A 220 ? - come on, where the heck did all the people go?)

A bit of searching and guessing brought me to this article in Freelance Traveller about converting from 1100 to Milieu 0. Maybe that's what what you came across?

(And I assume the Milieu 0 data in Travellermap is from the T4 supplement...)

https://www.freelancetraveller.com/features/rules/convert/1100to0.html

About sources: while searching I came across this article on Freelance Traveller, and realised I also have GURPS Traveller: First In around here somewhere. This is the GURPS equivalent of LBB Scouts; it has chapters on Stars, Worlds and Cultures (which gives an alternate sequence for detailing the universe).

 

[Geir]

Thanks for the list.
I don't have Mindjammer, but all the rest are in a pile next to my desk right now. Okay, Hard Times isn't; I have it somewhere, but for these purposes, it's not necessary. Though if you remember where someone wrote the guidelines for reverting 1105 data to Milleu 0, then I would be interested. I'm pretty sure I didn't hallucinate it, but I can't recall where it was... (and don't talk to me about the T4 First survey: Vland: B967344-A 220 ? - come on, where the heck did all the people go?)

A bit of searching and guessing brought me to this article in Freelance Traveller about converting from 1100 to Milieu 0. Maybe that's what what you came across?

(And I assume the Milieu 0 data in Travellermap is from the T4 supplement...)

https://www.freelancetraveller.com/features/rules/convert/1100to0.html

About sources: while searching I came across this article on Freelance Traveller, and realised I also have GURPS Traveller: First In around here somewhere. This is the GURPS equivalent of LBB Scouts; it has chapters on Stars, Worlds and Cultures (which gives an alternate sequence for detailing the universe).

Thanks!
I think that was it.
I also have First In - an actual paper copy - in my pile. And I forked out for a PDF copy of Mindjammer Traveller, too - research budget. Would probably grab a physical copy if I could, because I'm a hoarde- um, ah.. collector, yeah, that's it. (Pay no attention to the Mercenary set still lying on the bedroom floor).

 

[Rikki Tikki Traveller]

I am also excited about this...

My suggestion: Remember the original UWP generation tables were specifically designed for MAINWORLDS. When you want to create non-mainworlds, you need to have an expanded SIZE and ATMO generation method (Sizes should probably go up to about J to reflect super-Earth's). Also Gas Giants range in size from about Size J all the way up to about 1.5 Jupiter diameters (but mass goes up to about 20 Joves).

PLEASE try to use current planetary science info...

2nd Suggestion: GET RID OF FIXED ORBITS! I humbly suggest something like was used in the original 2300AD book - roll initial orbit, roll orbit multipliers.

I have actually been working on a version of this type of book myself and have a LOT of ideas. Happy to share what I have done privates if you are interested.

 

[NOLATrav]

I am also excited about this...

My suggestion: Remember the original UWP generation tables were specifically designed for MAINWORLDS. When you want to create non-mainworlds, you need to have an expanded SIZE and ATMO generation method (Sizes should probably go up to about J to reflect super-Earth's). Also Gas Giants range in size from about Size J all the way up to about 1.5 Jupiter diameters (but mass goes up to about 20 Joves).

PLEASE try to use current planetary science info...

2nd Suggestion: GET RID OF FIXED ORBITS! I humbly suggest something like was used in the original 2300AD book - roll initial orbit, roll orbit multipliers.

I have actually been working on a version of this type of book myself and have a LOT of ideas. Happy to share what I have done privates if you are interested.

This.

+1 on all this. Geir, I’ve been working on expanded system gen for quite some time, based on real-world science with a nod to ease-of-use and playability. Happy to kick some things out privately if you think they may be of help.

Best of luck with this!

 

[Geir]

Real science is messy (and not always anything more than somebody's non-provable model after you read twenty pages of an article...). I've been starting with the complicated, then parring down to the playable. Temperature stuff is a real bugger, if you want to do it right, but you don't need to do more than one temperature for a world if you don't want to. I'm also trying to emulate some of more specific stuff done in the old WBH so you could, in theory, if it mattered to the game, and if a fudge won't do, figure out the temperature range based on not only overall greenhouse effect and albedo, but for a particular latitude and altitude with a particular day length based on axial tilt and eccentricity, with other stars, time of year and day, and internal heat: one of those odd tools for the toolbox that you don't need to fix the sink but you might need once every twelve years - but not something you would do unless it you really needed to.

I've set the cut-off for planet Size at F - convenient from a hexadecimal standpoint and pretty much a cut-off before you get to mini-Neptunes. Gas giants get their own system with a a UWP kludge of size G, then S, M, L, for basic tee-shirt size mass range and then a hexidecimal value for diameters in Terras (so a gas giant size 4 is actual 4 x 8 size). Detailed mass range pushes from 10 Earths (Terras) all the way up to 4000 and after that it's a brown dwarf... Oh, and by extending the atmosphere types to G and H, you get G = gassy, mostly helium and H = Mostly hydrogen, so you could get a smaller 'gas dwarf' with a normal Size as a small as C. All this is provisional first draft stuff.

As I've said, Orbits has to stay in some form. What I've done so far is emphasize the fractional: tenths for numbers above 1, hundredths for those below, and orbit 0.00 set to 0.00 AU. Then I set a 'spread' value for the system, so each world orbit is a multiple of the spread (+/- the random fudge) - and the spread will mostly be less than one. So if the mainworld was at orbit 2.1 and the spread was 0.6, then the world orbit inside would be at 2.5 and the one outside would be at 2.7, etc. Spread can vary and so can the location - world#-wise - of the planet closest to the habitable zone. This allows for very compact systems and rather sparse ones. All with keeping within the T5 limit of mainworld + gas giants + belts + 2D worlds (I really, really wish that was 2D-2 instead, but not pushing it yet). Of course Orbits has to be converted to AU to do temperature and year-length calculation, among others, so handy table and formulas included for that...

One thing about reality though: it's complicated. A real orbit has six parameter, but Traveller orbits are only going to have two: semi-major axis (Orbit and AU for stars and planets, planetary diameters and kilometers for moons), and eccentricity. I'll make a note about the others, but leave it up to the OCD referee to work out dealing with those other four parameters on their own. Also, the model of a multi-star system is based on a primary star-centric view, sort of like T5 - my attempt to use barycenters went down the n-body wormhole and I realized I could get good enough answers without that complication.

92 pages into this first draft and still on physical characteristics, haven't started on social yet and I'm supposed to come in at 160 pages...

 

[MasterGwydion]

Real science is messy (and not always anything more than somebody's non-provable model after you read twenty pages of an article...). I've been starting with the complicated, then parring down to the playable. Temperature stuff is a real bugger, if you want to do it right, but you don't need to do more than one temperature for a world if you don't want to. I'm also trying to emulate some of more specific stuff done in the old WBH so you could, in theory, if it mattered to the game, and if a fudge won't do, figure out the temperature range based on not only overall greenhouse effect and albedo, but for a particular latitude and altitude with a particular day length based on axial tilt and eccentricity, with other stars, time of year and day, and internal heat: one of those odd tools for the toolbox that you don't need to fix the sink but you might need once every twelve years - but not something you would do unless it you really needed to.

I've set the cut-off for planet Size at F - convenient from a hexadecimal standpoint and pretty much a cut-off before you get to mini-Neptunes. Gas giants get their own system with a a UWP kludge of size G, then S, M, L, for basic tee-shirt size mass range and then a hexidecimal value for diameters in Terras (so a gas giant size 4 is actual 4 x 8 size). Detailed mass range pushes from 10 Earths (Terras) all the way up to 4000 and after that it's a brown dwarf... Oh, and by extending the atmosphere types to G and H, you get G = gassy, mostly helium and H = Mostly hydrogen, so you could get a smaller 'gas dwarf' with a normal Size as a small as C. All this is provisional first draft stuff.

As I've said, Orbits has to stay in some form. What I've done so far is emphasize the fractional: tenths for numbers above 1, hundredths for those below, and orbit 0.00 set to 0.00 AU. Then I set a 'spread' value for the system, so each world orbit is a multiple of the spread (+/- the random fudge) - and the spread will mostly be less than one. So if the mainworld was at orbit 2.1 and the spread was 0.6, then the world orbit inside would be at 2.5 and the one outside would be at 2.7, etc. Spread can vary and so can the location - world#-wise - of the planet closest to the habitable zone. This allows for very compact systems and rather sparse ones. All with keeping within the T5 limit of mainworld + gas giants + belts + 2D worlds (I really, really wish that was 2D-2 instead, but not pushing it yet). Of course Orbits has to be converted to AU to do temperature and year-length calculation, among others, so handy table and formulas included for that...

One thing about reality though: it's complicated. A real orbit has six parameter, but Traveller orbits are only going to have two: semi-major axis (Orbit and AU for stars and planets, planetary diameters and kilometers for moons), and eccentricity. I'll make a note about the others, but leave it up to the OCD referee to work out dealing with those other four parameters on their own. Also, the model of a multi-star system is based on a primary star-centric view, sort of like T5 - my attempt to use barycenters went down the n-body wormhole and I realized I could get good enough answers without that complication.

92 pages into this first draft and still on physical characteristics, haven't started on social yet and I'm supposed to come in at 160 pages...

Sounds great man! I do not envy you having to edit down what will probably be 250+ pages of material down to 160. Maybe save the other 70+ pages and do it as a PDF expansion to the mainbook, not required to use the mainbook, just cool add-on stuff that didn't fit in the mainbook. I know that I would live that. Not sure about how anyone else would feel about that among the fanbase or at Mongoose.

 

[phavoc]

Something that you may find helpful would be to post a chapter listing, with a short summary of what you want to accomplish with each chapter. Knowing tidal forces, orbital periods, etc, is important to building a more realistic system setting. However I don't think it's that important for playability. Knowing more about asteroid density (where can I had that pirate ship), or laying out what is reasonable for a planetary environment for an adventure is, I think, more useful to more players.

So knowing, kind of at least, what the chapters are going to be laid out and discussing might give people more opportunities to provide useful feedback in a targetted fashion.

 

[Geir]

Something that you may find helpful would be to post a chapter listing, with a short summary of what you want to accomplish with each chapter. Knowing tidal forces, orbital periods, etc, is important to building a more realistic system setting. However I don't think it's that important for playability. Knowing more about asteroid density (where can I had that pirate ship), or laying out what is reasonable for a planetary environment for an adventure is, I think, more useful to more players.

So knowing, kind of at least, what the chapters are going to be laid out and discussing might give people more opportunities to provide useful feedback in a targetted fashion.

That's a good idea. Not easy to do today, but I can do that soonish, especially as I go off on tangents. It's all first draft at this point, so focusing on some stuff and ignoring or scaling back others is definitely where input would be welcome. One point that I'm trying to make clear is that it's meant as a toolset for delving into what the referee feels is important to the adventure or campaign. Detailing every significant body in a system will lead to referee fatigue and create a lot of unused data.

Some things are just for color. Literally. I added a box for 'What Colour is the Sky' (complicated) and one for 'How Big is That Thing in the Sky?' (easy, mostly) and I want to do one for 'How Bright is That Thing in the Sky?' - but I want to make sure my math is both correct and simple to figure out before I tackle that one. And as for asteroid density, good luck with that: if you want to hide a pirate ship, you should try a ring system instead. Asteroids are too spread out - except maybe in a primordial system, which I'm putting in a cheekily named chapter called 'Special Circumstances' that I haven't gotten to yet...

 

[phavoc]

Something that you may find helpful would be to post a chapter listing, with a short summary of what you want to accomplish with each chapter. Knowing tidal forces, orbital periods, etc, is important to building a more realistic system setting. However I don't think it's that important for playability. Knowing more about asteroid density (where can I had that pirate ship), or laying out what is reasonable for a planetary environment for an adventure is, I think, more useful to more players.

So knowing, kind of at least, what the chapters are going to be laid out and discussing might give people more opportunities to provide useful feedback in a targetted fashion.

That's a good idea. Not easy to do today, but I can do that soonish, especially as I go off on tangents. It's all first draft at this point, so focusing on some stuff and ignoring or scaling back others is definitely where input would be welcome. One point that I'm trying to make clear is that it's meant as a toolset for delving into what the referee feels is important to the adventure or campaign. Detailing every significant body in a system will lead to referee fatigue and create a lot of unused data.

Some things are just for color. Literally. I added a box for 'What Colour is the Sky' (complicated) and one for 'How Big is That Thing in the Sky?' (easy, mostly) and I want to do one for 'How Bright is That Thing in the Sky?' - but I want to make sure my math is both correct and simple to figure out before I tackle that one. And as for asteroid density, good luck with that: if you want to hide a pirate ship, you should try a ring system instead. Asteroids are too spread out - except maybe in a primordial system, which I'm putting in a cheekily named chapter called 'Special Circumstances' that I haven't gotten to yet...

An outline may be very helpful to you as well.

I think you may find that being able to focus your effort on fleshing out the ideas to the right level will be a good use of your creative energies. One need not put the entire kitchen into the sink when all you need for now is the sink. I think the goal should be a book that gives players and referees a good understanding of how to build a star system so that it's fun and playable and believable. You may come up with the perfect design set for creating 1AU rings and dyson spheres for "infinite" playing area... but will that actually be useful to the majority of people out there interested in your product?

Remember that no good idea survives editing!!

 

[Geir]

An outline may be very helpful to you as well.

I think you may find that being able to focus your effort on fleshing out the ideas to the right level will be a good use of your creative energies. One need not put the entire kitchen into the sink when all you need for now is the sink. I think the goal should be a book that gives players and referees a good understanding of how to build a star system so that it's fun and playable and believable. You may come up with the perfect design set for creating 1AU rings and dyson spheres for "infinite" playing area... but will that actually be useful to the majority of people out there interested in your product?

Remember that no good idea survives editing!!

Oh, I've got an outline. But no good, bad, or indifferent outline survives contact with the writer. Hmm, Dyson spheres... I wasn't going to go there, or ring worlds, or Orbitals - now that last one really ought to be in Special Circumstances... nope. Already have too much to cover in the pages allocated.

 

[torus]

This sounds great and is something MgT fans have been wanting for a while. BTW I think one of the best - possibly the best - world generation systems that has ever been produced for Traveller is the one in Mindjammer Traveller. Worth a look if you haven't seen it.

 

[Rikki Tikki Traveller]

Based on current astronomy, I think Gas Giants should have FOUR sizes - Small GG (SGG) - Mini-Neptunes; Medium GG (MGG) - Neptunes, Large GG (LGG) - Saturn and Jupiter (100 -600 earth-masses); and Huge GG (HGG) - SuperJovians (5-30 jupiter-masses).

 

[Dalton Calford]

Hi Geir,
I just joined the forums and saw this post.
I have been working on this project for my own purposes, on and off for over a year.
I have been working through a great deal of material, as well as figuring out how to include/support earlier versions of Traveller.
I started with astronomy texts and support from friends who are studying this (benefits of living in a university city)
The article in JTAS 6 about how the traveller hexagonal map is a 2d mapping projection of 3d space (a great deal of the original article was left out due to space considerations and it being boring to non math types) was part of my project.
I have been automating the process I came up with as well, but, everything started with die rolling mechanics (including proper odds of haveing systems appear, based upon stellar density)
With the knowledge of a hexagon on a traveller map, being a cubic parsec, ie ~34.64 cubic light years, a single hex has more than enough room for multiple barycentres (a series of far systems, if using CT/MT terms) with each barycentre having the possiblity of containing one or more stars.
Then the stars have multiple zones, based upon temperature etc (simple black body emmision) and each zone can have multiple orbits.
So, if you are interested, reach out to me and I can provide you with my material.
I also included BioDensity/BioDiversity/BioComplexity for detailing biospheres.
I am currently working out the process of how to convert existing CT/MT/T5/MGT2 stated systems into

 

[Geir]

Based on current astronomy, I think Gas Giants should have FOUR sizes - Small GG (SGG) - Mini-Neptunes; Medium GG (MGG) - Neptunes, Large GG (LGG) - Saturn and Jupiter (100 -600 earth-masses); and Huge GG (HGG) - SuperJovians (5-30 jupiter-masses).

I sort of did it that way, there are small (which include Uranus and Neptune) Medium (Jupiter and Satrun) and large - superjovians to 13 Mj, which is the brown dwarf cut-off. I also added two atmosphere classes for oversized 'terrestrials' G, and H, helium-dominated and hydrogen dominated, so a world of size C+ could have an H atmosphere and be a mini-Neptune. All this is draft one (still ongoing) I'll need to work through it a few times to iron out how it works in practice rather than theory.