Anyone know of a game with a good solar system generator that is easy/quick to use but gives you more or less accurate results?

I like the Mongoose Traveller system except that it only really applies to terrestrial planets and expects you to handwave the gas giants.  I'd really rather have rules to use to accurately place the gas giants and give them different sizes and what not.

I've also looked at the GURPS Space (4th) and 2300 AD systems, but both of those apparently want me to spend hours doing math and tracking numbers just to generate a a quicky solar system.  I like that they are more accurate and all, but I don't want to role-play being an astrophysicist or a tax accountant for a couple of hours while doing my prep work.

Quote from: jgants;250903Anyone know of a game with a good solar system generator that is easy/quick to use but gives you more or less accurate results?

I like the Mongoose Traveller system except that it only really applies to terrestrial planets and expects you to handwave the gas giants.  I'd really rather have rules to use to accurately place the gas giants and give them different sizes and what not.

I've also looked at the GURPS Space (4th) and 2300 AD systems, but both of those apparently want me to spend hours doing math and tracking numbers just to generate a a quicky solar system.  I like that they are more accurate and all, but I don't want to role-play being an astrophysicist or a tax accountant for a couple of hours while doing my prep work.

Dang it, you just reminded me I was supposed to be working up some charts for that.

Mongoose Traveller does have a 'space opera' section that focusses more or less entirely on terrestrial-like planets, but there were some kind of goofy results from that, if I recall.

The Galaxies in Shadow one is mostly done.  There's no rules for generating civilizations yet, just physical data.

I've been working on an Excel spreadsheet that generates Classic Traveller subsectors and star systems using the Scouts book.  It's on hiatus now as I ran into a bit of a roadblock (read: got lazy) when I realized that I needed to have it potentially generate dozens of moons per system (I know macros and VBasic would make it easy, but this is a sort of self-challenge: do it using formulas only!).  Reduces an hour of work per system to a simple SHIFT+F9.

I really need to finish that thing up.

Quote from: KenHR;250920I've been working on an Excel spreadsheet that generates Classic Traveller subsectors and star systems using the Scouts book.  It's on hiatus now as I ran into a bit of a roadblock (read: got lazy) when I realized that I needed to have it potentially generate dozens of moons per system (I know macros and VBasic would make it easy, but this is a sort of self-challenge: do it using formulas only!).  Reduces an hour of work per system to a simple SHIFT+F9.

I really need to finish that thing up.

Shoot it over when you are done, I might be able to set it up in a database.  I have been meaning to play around with the Ultimate++ IDE I installed recently, and it looks like a fast prototyping kind of project.

Quote from: StormBringer;250953Shoot it over when you are done, I might be able to set it up in a database.  I have been meaning to play around with the Ultimate++ IDE I installed recently, and it looks like a fast prototyping kind of project.

Now I have a reason to finish the damn thing.

Really, I just have to do the formulae for moons...just a lot of them to potentially do!

And when it is done and you look at the sheet, you're not allowed to laugh at my kludgy formulae...though I did learn a couple tricks in the course of making this one.

Quote from: KenHR;250962Now I have a reason to finish the damn thing.

Really, I just have to do the formulae for moons...just a lot of them to potentially do!

And when it is done and you look at the sheet, you're not allowed to laugh at my kludgy formulae...though I did learn a couple tricks in the course of making this one.

If it's a kludge and it works, it's not a kludge.  

I use AstroSynthesis.

-clash

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).

Quote from: flyingmice;250986I use AstroSynthesis.

-clash

How do you like it? I've been leaning towards buying it myself.

Quote from: CavScout;251143How do you like it? I've been leaning towards buying it myself.

It's excellent! I did all the solar system generation for the Oikumene* of Cold Space and FTL Now using it. Saved me eons of work!

*The Oikumene is the approximately 20 LY diameter sphere around Earth where the major extrasolar colonies all are. There are small private colonies established past the Oikumene, but little is known about them.

-clash

Quote from: flyingmice;251148It's excellent! I did all the solar system generation for the Oikumene* of Cold Space and FTL Now using it. Saved me eons of work!

*The Oikumene is the approximately 20 LY diameter sphere around Earth where the major extrasolar colonies all are. There are small private colonies established past the Oikumene, but little is known about them.

-clash

I'll bet they are hippies.  Space hippies.

KHAAAAAAAAAAAN!

Quote from: StormBringer;251154I'll bet they are hippies.  Space hippies.

KHAAAAAAAAAAAN!

Some of them definitely are.

-clash

Quote from: flyingmice;251148It's excellent! I did all the solar system generation for the Oikumene* of Cold Space and FTL Now using it. Saved me eons of work!

*The Oikumene is the approximately 20 LY diameter sphere around Earth where the major extrasolar colonies all are. There are small private colonies established past the Oikumene, but little is known about them.

-clash

Nice, you may have jsut persuaded me to drop down the cash for it.

Quote from: CavScout;251170Nice, you may have jsut persuaded me to drop down the cash for it.

The Astrosynthesis files for Cold Space and FTL Now are freely downloadable - click on the links. Nbos has a trial version that can read these files - click on the link! This'll let you see what is possible with this program.

-clash