I've been dicing up subsectors for my Traveller game and decided to try the Space Opera/Hard Sci-Fi algorithms from Mongoose Traveller.
Instead of system after system of overpopulated airless pebbles (and pebbles with air) and uninhabited garden worlds with class A starports I now have a bunch of grittier systems. Uninhabited airless rocks, populated systems with class E and X starports. I like the results.
The standard Traveller procedure works for areas that have been inhabited and terraformedb for thousands of years, but the alternate Mongoose system gives me a hardscrabble frontier, like something out of Alien/s. A region with far more wiggle room for grifters, hustlers, warlords and murder hoboes.
I also like the systems in Book 6: Scouts. Any other alternate procedures anyone can recommend?
Keep an eye on the science wires for new and interesting theories/facts about the universe, there's usually something wacky but big fun every couple of weeks.
Quote from: Planet Algol;717464I also like the systems in Book 6: Scouts. Any other alternate procedures anyone can recommend?
if you have copies of DIASPORA or GURPS SPACE, they've got system/planet-gen routines -- the former cleverly quick'n'dirty, the latter pointlessly detailed.
Generally I have been using Heaven and Earth, but someone is working on a new generator based off of T5 (no world map yet); though I will do a sector at a time and weave it all together, changing things as needed. But there isn't one way to do it, certain assumptions have to be made, such as High Tech or Low Tech for example.
Here are some of my favorites from The Missouri Archive (http://traveller.mu.org/):
Alternative World Generation Rules (http://traveller.mu.org/house/altWorldGeneration.html)
The Book 6 Scouts Update (http://traveller.mu.org/house/egs.html)
Or for something a little more fantastic, Try the Star Frontiers Star System Generator.
Reprinted here for your convenience:
STAR FRONTIERS STAR SYSTEM GENERATOR
By Scott Ireland
There are many times when the players will want to go and explore new stars. Given the vast expanse of space, there are virtually infinite stars the players could visit. A referee may often have to generate solar system's on the fly as the players decide where they wish to go. It can be a difficult task as there are many questions that must be answered. What follows is a guide for generating star systems. It should be noted that some broad assumptions are made. This by no means is meant to cover every single cosmic condition possible. It is merely a tool for creating worlds within an imaginary setting.
STAR LOCATION
The first step is to determine if a particular space contains a celestial object. There are several methods for doing this:
METHOD 1
The referee can generate a star system as the players demand for it. Should the players wish to travel in a particular direction, the referee can simply say they will come across a star after so many light years. Roll on the following table:
Roll (d10) Result
1-5 Star is d10 LY distant in the desired direction.
6-10 Star is d10 + 10 LY distant in the desired direction.
If the players travel to the star, proceed to the section on SOLAR SYSTEM GENERATION for further details.
METHOD 2
The referee can map out a region of space ahead of time. The referee can just simply place the stars (10d10) and nebula where he or she wishes on a standard piece of grid graph paper. The referee can generate the solar systems ahead of time, or wait until the players travel to the star and generate them as needed.
METHOD 3
The referee can map out a region of space ahead of time using random die rolls to place celestial objects. The referee would take a sheet of standard grid paper and roll for each space on TABLE IA. Should the referee desire a higher probability of stars being present, a modifier of 1 or 2 could be added to the roll:
TABLE IA
Roll (d10) Result
1-8 Empty
9 Nebula
10+ Star
Nebula's tend to be large in size. If a nebula is indicated, roll on TABLE IB for each square that touches a nebula square. If a nebula is no longer indicated, switch to TABLE IA. The type of nebula can be found by rolling on TABLE IC.
TABLE IB
Roll (d10) Result
1-4 Empty
5-9 Nebula
10+ Star
TABLE IC
Roll (d10) Result
1-4 Absorption Nebula
5-8 Emission Nebula
9-10 Stellar Nebula
Explanation of Nebula Types
Absorption Nebula These nebula are made up of "dark matter", containing no developing stars.
Emission Nebula These nebula are made up of the gases of developing stars.
Stellar Nebula These nebula are made up of the debris from stars that have gone nova. They are more dangerous to navigate through due to high levels of shock waves and radiation.
Should a star be indicated on either table, continue with the section on SOLAR SYSTEM GENERATION.
SOLAR SYSTEM GENERATION
The next step is to determine what type of star is present. Roll first on TABLE IIA for the number of stars, and then roll on TABLE IIB; once for single stars, twice for binary stars.
TABLE IIA
Roll (d10) Result
1-7 Single Star
8-10 Binary Star
TABLE IIB
Roll (d10) Result
1 Black Hole / Neutron Star (50% / 50%)
2-10 Normal Star - Roll on TABLE III
TABLE III
Roll (d10) Class Max. Planets #1 Habitable #2
1 WD (White Dwarf) 0 no
2 M 10 no
3 K 15 yes
4 G 15 yes
5 F 10 yes
6 A 5 no
7 B 0 no
8 O 0 no
9 RG (Red Giant) 5 no
10 SG (Super Giant) 0 no
#1 Indicates the maximum number of planets possible in the system.
#2 Indicates that the system has the possibility to contain habitable planets.
For the main sequence stars (roll 2-8 on TABLE III), roll an additional d10. This is the star's spectral subclass (0-9).
For binary stars, the max. planets number is divided in half for each star.
Once the type of star has been determined, the number of planetary orbits must be computed. This can be done by using the following formula, where P = # of Planets:
P = d100 x (Max. Planets / 100)
After the number of planets have been determined, each world must then be classified by what ZONE it is in. There are 3 possible zones for habitable systems: Inner Zone, Habitable Zone, and Outer Zone. There are 2 possible zones for inhabitable systems: Inner Zone and Outer Zone. This may seem confusing, but it is important. Planets in the Inner Zone (i.e. closer to the sun) are more likely to be hotter, with a reduced chance for a standard atmosphere and liquid water. Worlds in the outer zone (i.e. farther away from the sun) are more likely to be colder with reduced chances for a standard atmosphere and liquid water as well. Planets in the habitable zone are more likely to contain an atmosphere and liquid water capable of supporting life. It should be noted that because a world is in a habitable zone doesn't mean it will be habitable.
Systems marked as habitable should first determine which orbit is the base HZ (habitable zone):
HZ = P / 3
In addition, there is a chance that up to 2 additional planets may be habitable. Roll on the following 2 tables:
TABLE IVA
Roll (d10) Result
1-5 One planet closer towards the star (HZ - 1) is habitable (if the planet exists).
6-10 Next closer planet isn't habitable.
TABLE IVB
Roll (d10) Result
1-5 One planet further from the star (HZ + 1) is habitable (if the planet exists).
6-10 Next further planet isn't habitable.
Every planet number between the lowest habitable zone and the star is considered in the Inner Zone.
Every planet number larger than the highest habitable zone is considered in the Outer Zone.
For star systems that contain planets, but aren't habitable, the base outer zone is figured by the following formula:
OZ = P / 3
Any planet number between the star and the above number is considered in the Inner Zone. All of the rest of the planets are considered in Outer Zone.
WORLD CREATION
Now that we know what our star is, how many planets there are, and which zone each planet is in, we can flesh out some of the general details about each world. We will first determine the type of world present. For each planet, roll on the following table:
TABLE IV
Roll (d10) Result
1-2 Asteroid Belt
3-6 Planet
7-10 Gas Giant
WORLD SIZE (S)
Each world will have a size associated with it. For each world, roll on the appropriate table below:
ASTEROID BELT (AB)
All asteroids are considered to have a size of 0 (S0).
PLANET (P)
Roll (d10) Result (Diameter x1000 km)
1-5 d10
6-10 d10 + 10
GAS GIANT (GG) *
Roll (d10) Result (Diameter x1000 km)
1-5 10 + 10d10
6-10 100 + 10d10
* Gas Giants have a 50% chance of having rings (r)
ATMOSPHERE (A)
Once the world sizes are determined, the type of atmosphere on each world can be found. For each planet, roll on the following table, noting the exceptions and modifiers that follow:
Roll (S + d10 - d10) ** Result
0- None
1 Trace
2 Very Thin *
3 Thin *
4 Thin *
5 Standard *
6 Standard *
7 Dense *
8 Dense*
9 Very Dense *
10+ Exotic
** Modifiers to Atmosphere Type
Inner / Outer Zone Worlds Roll (d10) Result
1-6 Roll @ -5
7-9 Exotic Atmosphere - ignore roll
10 No modifier
World S0 or S1 No Atmosphere - ignore roll
Gas Giant Exotic Atmosphere - ignore roll
* 50% Chance of being tainted (!)
Explanation of Atmosphere Types
Trace This atmosphere contains just a hint of gas. Characters must wear a space suit in order to survive.
Very Thin This atmosphere is slightly denser than Trace. Characters must wear a space suit in order to survive. Characters exposed without protection can survive for a number of rounds equal to their STAMINA score, taking 1 point of damage per round.
Thin Characters can survive in this atmosphere without protection. Due to the low pressure, characters will tire more easily (i.e. adventure for only half as long as normal). During times of strenuous physical exertion (ex. Combat), a STAMINA check must be made per round. A failed check indicates that all activities are at a -2 CS penalty until the character rests or is treated (i.e. given a Stim Dose).
Standard Characters suffer no ill effects in this type of atmosphere.
Dense Characters can survive in this atmosphere without protection. Due to the high pressure, characters will tire more easily (i.e. adventure for only half as long as normal). During times of strenuous physical exertion (ex. Combat), a STAMINA check must be made per round. A failed check indicates that all activities are at a -2 CS penalty until the character rests or is treated (i.e. given a Stim Dose).
Very Dense Characters must wear a space suit in order to survive in this type of atmosphere. Characters exposed to this air without protection can survive for a number of rounds equal to their STAMINA score, taking 1 point of damage per round.
Exotic This atmosphere contains a wild mix of numerous lethal gases. Characters must wear a space suit in order to survive.
Tainted Atmospheres marked as tainted (!) are not breathable without some protection. Characters must wear some sort of filter mask in order to survive, or suffer the effects of the air (poison, corrosive, etc.)
HYDROGRAPHICS (H)
After the atmosphere as been determined, each worlds hydrographics (surface liquid) can be determined. Roll for each world on the following table, noting the modifiers that follow:
Roll (S + d10 - d10) ** Result *
0- None
1 10%
2 20%
3 30%
4 40%
5 50%
6 60%
7 70%
8 80%
9 90%
10+ 100%
** Modifiers to Hydrographics Type
Inner Zone Worlds No water - ignore roll
Outer Zone Worlds Roll (d10) Result
1-9 Roll @ -5
10 No modifier
Atmosphere <= Trace (A1) or >= Exotic (A10) Roll @ -5
Gas Giant 100% Liquid
* If the atmosphere is exotic (A10), then the surface water is tainted (!). Otherwise, there is a 50% chance the surface water is tainted.
Explanation of Hydrographic Types
Gas Giant Gas Giants will contain a liquid surface, though this is usually a liquid metal of some form.
Outer Zone Non gas giants in the Outer Zone with a hydrographics rating will have their surface water in the form of ice.
Tainted The surface water must be filtered before it can be used. It can be poison, corrosive, etc.
MOONS (M)
One final detail to add is the number of moons a world may have. The number of moons are determined by the following table:
Roll (d10) Result
1-3 #M = (S / 10) - d5
4-7 #M = (S / 10)
8-10 #M = (S / 10) + d5
Most moons will be small airless, waterless planetoids (S0/A0/H0). A few might contain an atmosphere and water. For each moon, roll on the following table. If a higher chance of a special moon is desired, a modifier of 1 or 2 can be added. Moons are considered to be in the same ZONE as the world they orbit. Moons must be of a size less than the world they orbit.
MOON SIZE
Roll (d10) Result
1-9 S0/A0/H0
10+ S = d10 roll for A and H
EXAMPLES
Here are some example systems, showing notation that can be used when describing them. The following guide shows what the TYPE and STATISTIC notations represent:
P = Planet
AB = Asteroid Belt. All Asteroid Belts have S0/A0/H0/M0 as their statistics.
GG = Gas Giant. All Gas Giants have A10/H10 as their statistics.
S = Size.
A = Atmosphere
H = Hydrographics
M = Moon.
+ = World in Habitable Zone
! = Tainted
r = Rings
EXAMPLE 1
Star Orbit Type Statistics
G7 1 P+ S6/A4/H3/M0
2 AB
3 GG S75r/M6
M2 S4/A2/H1!
M6 S10/A5!/H5
4 GG S50/M2
NOTES:
Star is single. It is class G7 with 4 worlds.
World 1 is within the habitable zone (+). It is 6000 km (S6) in diameter. It possesses a thin atmosphere (A4). It is 30% covered in water (H3). It has no moons (M0).
World 2 is within the outer zone . It is an asteroid belt.
World 3 is within the outer zone. It is a gas giant that measures 75,000 km in diameter and has rings (S75r). It has 6 moons (M6). Moons 1, 3, 4, 5 are all small planetoids. Moon 2 has a very thin atmosphere (A2) and 10% covered in toxic ice (H1!, outer zone). Moon 6 is a large moon (S10) and has a tainted standard atmosphere (A5!). It's surface is covered by 50% ice (H5, outer zone).
World 4 is within the outer zone. It is a gas giant that measures 50,000 km in diameter (S50). It has 2 small moons.
EXAMPLE 2
Star Orbit Type Statistics
O4
K2 1 P S2/A0/H0/M0
2 P+ S6/A10/H0/M0
3 P+ S6/A5/H6/M1
M1 S2/A0/H0
4 AB
5 GG S62r/M2
6 P S3/A0/H0/M0
NOTES:
Star is binary. The primary star is class O4 with no planets. The secondary star is class K2 with 6 worlds.
World 1 is in the inner zone. It is 2000 km in diameter (S2). It has no atmosphere, water, or moon (A0/H0/M0).
World 2 is in the habitable zone (+). It is 6000 km in diameter (S6). It has an exotic atmosphere (H10). It has no water or moons (H0/M0).
World 3 is in the habitable zone (+). It is 6000 km in diameter (S6). It has a standard atmosphere (A5). It is 60% covered in water (H6) and has 1 moon (M1). Moon 1 is 2000 km in diameter (S2) and has no air or water (A0/H0).
World 4 is in the outer zone. It is an asteroid belt.
World 5 is in the outer zone. It is a gas giant. It is 62,000 km in diameter with rings (S62r). It has 2 moons (M2). Both moons are small planetoids.
World 6 is in the outer zone. It is 3000 km in diameter (S3). It has no atmosphere, water or moon (A0/H0/M0).
I should also mention, if you are looking for a star system generation or world generation computer program there are a lot out there. These are a few that I like:
Donjon's Traveller Simple System Generator. (http://donjon.bin.sh/scifi/tsg/)
The Worldbuilder Deluxe (http://www.downport.com/wbd/World_Builder_Deluxe.htm)
A bunch to sort through on Freelance Traveller. (http://www.freelancetraveller.com/infocenter/swlist/winprogs.html)
And 1001 Subsectors from the beloved Zhodani Base. (http://zho.berka.com/stuff/generators/random-subsector-generator/)
Quote from: jeff37923;717502I should also mention, if you are looking for a star system generation or world generation computer program there are a lot out there. These are a few that I like:
Donjon's Traveller Simple System Generator. (http://donjon.bin.sh/scifi/tsg/)
The Worldbuilder Deluxe (http://www.downport.com/wbd/World_Builder_Deluxe.htm)
A bunch to sort through on Freelance Traveller. (http://www.freelancetraveller.com/infocenter/swlist/winprogs.html)
And 1001 Subsectors from the beloved Zhodani Base. (http://zho.berka.com/stuff/generators/random-subsector-generator/)
Does anyone remember a program for Star Master (the SF version of Rolemaster) that would generate a galaxy, solar systems, planets, even right down to city maps?
It was all in ASCII graphics (this had to be the early 90s), but it was really amazing, yet I can't find it again. I remember getting it from a BBS...
Quote from: JeremyR;717511Does anyone remember a program for Star Master (the SF version of Rolemaster) that would generate a galaxy, solar systems, planets, even right down to city maps?
It was all in ASCII graphics (this had to be the early 90s), but it was really amazing, yet I can't find it again. I remember getting it from a BBS...
Wow. If you can find that, I would love to try it out!
You will have to dig a bit, but Evil Dr Ganymede, aka Dr Constantine Thomas, has an alternative world gen process. He set up Mongoose Traveller's alternate rules, I believe.
http://evildrganymede.net/rpgs/stellar-mapping/
So much useful stuff -- thanks! I've been playing Stars Without Number, but I see that Traveller worldgen is a bit more in-depth, and these alt versions look fun to try, too.
I wrote programs that use various Traveller edition worldgens, and GURPS Space worldgens. I too like the Mongoose Scout book for system building. Lately I've been using the space opera settings. SPI Universe is my favorite world generator still.
I use a mix of Book 6, DGP's Grand Survey, and GURPS Space.
FGU's Space Opera had some nifty bits, if memory serves, such a set of planet types described in terms of orbital eccentricity and axial tilt.