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Realistic Science-Fiction RPG Star Maps

ExileInParadise

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Early Sci-Fi RPGs
The earliest science-fiction RPGs were set on planets or within starships and did not include much at all regarding the stellar neighborhoods around them:
  • 1975 Empire of the Petal Throne set on the world of Tékumel.
  • 1975 Blackmoor set on the worlds Mystara, Greyhawk, Wilderlands, and Pelinore over the years.
  • 1976 Metamorphosis Alpha set inside the massive starship Warden.

2D Empire Building
In 1977, Traveller [1] by Game Design Workshop started humbly with a simple system of plotting 2D "space sectors" on hex paper.

In the 40+ years since, that humble beginning has lead to a massive sprawling empire of more than 11,000 systems detailed on a random-generated 2D map [2].

Since Traveller's earliest days, a recurring question is "why not use 3D star data and make the map 3D?"

The usual answers are ease of use and simpler math.

On a 2D map, you can simply "walk" your fingers from start to end and count along the way.

In 3D mapping, this doesn't work.

With a 2D map, the Distance between two star coordinates equals the Square Root of ( (EndingX - StartingX)^2 + (EndingY - StartingY)^2 )

Thanks Pythagoras!

With a 3D map, the math is ... less easy:
Distance = Square Root of ( (EndingX - StartingX)^2 + (EndingY - StartingY)^2 + (EndingZ - StartingZ)^2 )

Science-Fiction RPGs with Realistic Maps
Despite the ease of use and math friction, that did not stop some game companies exploring 3D star maps.

The earliest game based on a 3D map I have is Universe [3] by SPI from 1981.

Game Design Workshop released a futuristic Twilight 2000 update in 1986 called Traveller: 2300 [4] including a star map based on Gliese's Near Star Catalog.

In 1993 TSR published Amazing Engine: Bughunters [5] with a map very similar to the map from SPI's universe (possibly because TSR had acquired SPI years before).

Despite the occasional forays into realistic star maps, many or most games followed Traveller's lead, just including their own 2D maps of space to explore or systems to build 2D maps.

Recent Developments
In recent years, the availability of high-quality near star data and the computer power to easily manipulate it has led to a number of games which give 2D presentations of 3D star data.

Three examples:
  • 2016 Near Space[6] by Stellagama [7]
  • 2017 Hostile [8] by Zozer Games Free Maps and Other Downloads [9]
  • 2020 "The Stars of the Middle Heavens" map [10] by Fria Ligan/Free League for the ALIEN RPG.
Fundamentally, all three of these examples are based on the same core data and presented in the same manner using a standard "+X points to galactic core and Y plane is the plane of the galaxy" layout.

This allows you to intermix and interchange these maps and their data, or use data from these games to expand the others.

Building Your Own Realistic 2D *and* 3D Starmap From The Same Data
Even better, the 3D star maps described above all build from real astronomical data sources and you can too.

With the release of Traveller: 2300, gaming guru Winchell Chung began "Project Rho" to explore, explain, and expand on 3D star mapping for his own personal interest, which he also moved onto the world wide web to share with others.

Over time, Project Rho expanded into Atomic Rockets, a massive reference site about all things spaceflight.

OBLIGATORY WARNING: WARPED SPACETIME!
Visiting Project Rho and/or Atomic Rockets may result in lost time and productivity - these sites are a very cool vortex of science fiction information deceptively easy to get lost in for hours or days.

Winchell Chung put together the HabHYG [11] star maps and data and makes them freely available to improve the state of star mapping in literature and games.

From the link, you can download PNG and PDF map images, data spreadsheets, connection lists, and the StereoStar program with data files for:
  • 52 stars within 15 l.y.
  • 111 stars, 17 habitable, within 20 l.y.
  • 277 stars, 51 habitable, within 30 l.y.
  • 572 stars, 121 habitable, within 40 l.y.
  • 998 stars, 211 habitable, within 50 l.y.

These maps can be used as-is for plenty of science-fiction role-playing and have 3D coordinate data and can be plotted in 2D allow you to use and re-use them as you see fit.

The spreadsheet data format is documented for use with other tools.

3D Map Management
If you would like to visualize the 3D space, as well as track GM friendly information about planets, stations, stars, and empires within it, the "go to" tool for 3D star map management is AstroSynthesis [12] by NBOS Software.

Being able to plot, rotate, pivot, and pan through the 3D map data, and tag GM information to anything is a great management help.

My favorite feature of AstroSynthesis is one that touches on the hardest part of star map management... building the solar systems around those stars.

AstroSynthesis can build a stellar system from your star data with push-button ease.

This can save a GM many hours spent throwing dice at planet-building charts which is the procedure generally used within RPGs such as Traveller, FTL: 2446 and Midnight at the Well of Souls, or Traveller: 2300/2300 AD.

A Final Thought...
Of course, all of this may be far too much time, effort, and/or money for the harried GM to bother with.

If you just need a space map, and you need it right now, you cannot go wrong with The Only Sci-Fi Star Chart You'll Ever Need [13].

Disclaimer and Disclosure
Not every science-fiction RPG could be covered here.
This list primarily touches on games contained in the my personal library.
I provide financial support to Atomic Rockets through Patreon.
I am also an AstroSynthesis license holder and long-ago script contributor.

References
[1] https://en.wikipedia.org/wiki/Traveller_(role-playing_game)
[2] https://www.travellermap.com
[3] https://en.wikipedia.org/wiki/Universe_(role-playing_game)
[4] https://en.wikipedia.org/wiki/2300_AD
[5] https://en.wikipedia.org/wiki/Amazing_Engine
[6] https://www.drivethrurpg.com/product/192332/Near-Space
[7] https://www.stellagamapublishing.com/
[8] https://www.paulelliottbooks.com/hostile.html
[9] https://www.paulelliottbooks.com/hostile-resources.html
[10] https://www.geeknative.com/65748/alien-rpg-stars-of-the-middle-heavens-and-campaign-play/
[11] http://www.projectrho.com/public_html/starmaps/mapindex.php#winch
[12] https://nbos.com/products/astrosynthesis
[13] https://boingboing.net/2017/04/17/every-sci-fi-star-map.html
 
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ExileInParadise

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Here's an example of the HabHYG50ly realistic star map data in use.

I've pasted up a draft of my version of the Free League ALIEN RPG starmap data, with 2D/3D coordinates using Winchell Chung's HabHYG 50ly data.

Systems that I could not match up were commented as ## XXX.

The rest of the data is in CSV format with a header line explain the fields, which are also detailed on Winchell Chungs HabHYG download page.

https://pastebin.com/jwf85iHs

This should be easily convertible to use in NBOS AstroSynthesis 3 or with Winchell's own StereoStar program.

And an additional note since its implied rather than stated:
The 2D map coordinates are the Xg, and Yg, parts of the 3D coordinates - so you get both in the same place.
The 3D coordinates allow you to find the true distance (and time required) for jumps from star to star.
Distance = square root of ( (X2 - X1)^2 + (Y2 - Y1)^2 + (Z2 - Z1)^2 ) where XYZ1 is your start system and XYZ2 is your destination.
https://dqydj.com/3d-distance-calculator/

The map changes dramatically once you start looking at the true distances between places...

In the Display Name field, I've added tags for the polities:
3WE is Three World Empire (UK, etc)
UA is United Americas
UPP is Union of Progressive Peoples
ICSC is Independent Core Systems Colonies
I've also put colony or station name followed by the Alien Map name etc.
 

JochenL

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I thought I could go with Near Space. I wanted to use it for expanding the Euro Sector not described in Hostile. It only contains twelve systems of the subsector "Konigreich", though. Easy, I thought, I will just expand it using publically available data. Then everything broke. The map seems to arbitrarily distribute known systems on a 2D grid. Stars are not located relative to each other as I would expect from consulting first and second sources.

Now I will roll my own.

EDIT: I will start with SIMBAD. This is my query: http://simbad.u-strasbg.fr/simbad/s...list.plxsel=on&list.fluxsel=off&notedisplay=A
 
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JochenL

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This is my current state, all stars within 15 parsecs of Sol, seen from Galactic North. Top is Coreward, Left is Spinward, etc., 1 square = 1 parsec.
I used the Galactic Longitude and Distance from Sol to calculate 2D coordinates, so direction and distance from Sol are true.
To thin out the boundary, I will reduce the sphere of the source data to a disc and drop some stars.

temp.png
 

ExileInParadise

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I thought I could go with Near Space. I wanted to use it for expanding the Euro Sector not described in Hostile. It only contains twelve systems of the subsector "Konigreich", though. Easy, I thought, I will just expand it using publically available data. Then everything broke. The map seems to arbitrarily distribute known systems on a 2D grid. Stars are not located relative to each other as I would expect from consulting first and second sources.

Now I will roll my own.

I had not tried expanding Hostile or Near Space that way - but I do know that stuff was "moved" to fit more in the Traveller-style hex maps - so its not surprising.

And, you reminded me - we should probably pester Paul Elliott for the rest of the HOSTILE map ... the sectors are named ... I'd bet he's got them in his notebooks.

I also found the ALIEN RPG star map "fudged" quite a few things.

The only way I've seen really work well with real data is the NBOS AstroSynthesis program ($PAID)
... or you can use Winchell Chung's StereoStar program and HabHYG data.

There is a really great data set for AstroSynthesis based on HIPPARCOS data for all the stars within 100 l.y created by Terry Kepner - available from the NBOS download pages.

That's what I've been using for my personal sci-fi game - almost 2500 star systems is "plenty"

I setup my story such that the further humanity has explored is ~48 l.y. which is basically half the available radius.

Lots of room for interior developed star systems (sandbox) and exploring further out (hexcrawl).
 

ExileInParadise

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My Salvage Space star map with the core setting system Gliese 14 / BD +40 45 highlighted

1652390671400.png
 

JochenL

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Are there Cepheus-based System generation rules out there?
 

ExileInParadise

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Are there Cepheus-based System generation rules out there?

SOLO by Zozer Games has one as part of its "Scouts" solo campaign - you solo roleplay mapping and exploring a new star system as part of mapping a new sector of space from scratch.

But, any Traveller 2d6 system will work too, especially Classic Traveller or Mongoose Traveller v1 - which Cepheus is derived from:
http://taunoyen.com/traveller/SystemGenerator.html
https://wiki.rpg.net/index.php/RTT_Worldgen

As much fun as it is to chuck dice, generating sectors and star systems is hours of rolling.
I tend to use a tool like AstroSynthesis, StarForm, or one of the online generators like that one above.
 

JochenL

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I thought I could go with Near Space
After some serious calculation, I am pretty sure that there are several "errors" due to misinterpreting data. Equatorial (right ascension and declination) and galactical coordinates (longitude and latitude) are right-handed systems, i.e., hours/angles increase COUNTER-clockwise. Additionally, equatorial coordinates have a tilted plane (based on Earth's equator) and are oriented towards equinoxes and not the galactic core/rim. In the map I am creating this is changed to galactic coordinates in the right-hand system and correctly oriented towards coreward, rimward, spinward, and trailing.
 

ExileInParadise

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After some serious calculation, I am pretty sure that there are several "errors" due to misinterpreting data. Equatorial (right ascension and declination) and galactical coordinates (longitude and latitude) are right-handed systems, i.e., hours/angles increase COUNTER-clockwise. Additionally, equatorial coordinates have a tilted plane (based on Earth's equator) and are oriented towards equinoxes and not the galactic core/rim. In the map I am creating this is changed to galactic coordinates in the right-hand system and correctly oriented towards coreward, rimward, spinward, and trailing.

Welcome to the eternal tradeoff between "simulation" and "abstraction".

The funny part is - even astronomers can't agree on the real positions of things ... the HIPPARCOS data, for example, has a correction applied to it in order to deal with a malfunctioning thruster that left it in a more elliptical orbit than originally planned.
That skews all of the parallax data.

The sad part is that you sound like me - even if the data is "good enough" for a table game - knowing its "not right" somehow still bothers you.

On another, related, thread, Stephan asked me "all that is great, but what do you use it for at the table?" which is a great question to hone prep like this.

Do your players, or their characters, need astronomer accurate stellar data in order to play the game and solve the encounters?

This is one of the places where the Traveller grognards smile and nod.

The debate on "2D" sector maps versus "3D" sector maps goes back to the 1970s and usually ends up like this:

If you want to do the extra work, go for it but it really gets you nothing extra for Traveller by going 3D.

Traveller mappers take a page of hex paper, and almost literally flip a coin hex by hex:
Heads there's a star system to adventure in for that hex and tails, there's not.

Now, you have a sandbox to space trade in - done and dusted!

The reason I mention all of this comes from my view that ultimately, the role of a GM is to "cast illusion" on a table.

If this level of detail is what you need to cast your spell - great! Do it!
But, if you can cast illusion and throw a great game with less - then that is great too.

Traveller players and their 2D flat maps that have no basis in space (despite having SOL on the map!?!) still have fun and ignoring the technical discrepancy is part of the contract to do that.

Everyone knows the data is made up - and plays anyway because the data still enables the fun.

The message here is "be willing to use 'willing suspension of disbelief'" when you're casting your GM illusions.

That is part of why I simply cheat like a fiend and get a program to draw me the night sky map from the planet/star I've chosen as a stage.

Is that map correct? No idea - I couldn't begin to do the math and spend the time to validate the data.

Do I have a cool night sky map to fire my, and my players, imaginations? Heck yeah! Game On!

So, be willing to give yourself permission to "fudge the details" in favor of fun, especially when it comes to background stuff like this.

And no, its not easy - the starmap in the ALIEN RPG still taunts me with its "so close, but NOT RIGHT" aspects.
Can I game on it as is? Certainly.
Can I fix it? Maybe ... and someday I may spend the time to do so...

So, here's the 64 million quatloo question:
Can you run your space game on the Near Space map and have fun as well as help a group of others have fun?
I bet the answer is still yes...
 
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