captainjack23
Cosmic Mongoose
star system generation:
A modest proposal
I suggest that a problem lies in conceptualizing what the sector maps are intended for. Generally they are seen as maps, and used to describe the geography of the area in question.
Conceptually, a better approach to the problem is to view them as charts rather than maps. The difference is that a map is detail and accuracy oriented, and highly descriptive. A chart is only accuracy oriented when it is functional. A great example is the age of exploration portolan charts - they have very fiddly detail about coasts, the depths and hazards within a few miles of the coast, and where fresh water is available on the coast.....and nothing else, just white space, inland. They were for Navigators, not cartographers or scientists.
I think reframing the traveller system maps this way will help. The subsectors are already obvious functional abstractions, given the actual stellar density compared to the charted planets with starports. They are clearly a navigators reference: where are the ports the inhabited planets, the interesting stuff; and where are the shoals: red zones, and rifts.
From the viewpoint of a working navigator, It seems like you need a bare minimum of information other than the planet.
1. where is it (which orbit)
2. Are there other important ports insystem.
3. how big is the 100/10d limit for the star
(this actually should be priority 1, I imagine,)
4. since we may or may not be playing space opera, and optional consideration is where are the asteroid belts .
5. where are the gas giant(s), if any.
A trader may have one more question: are there useful resources off(main) planet ?
So, the question is, I feel, NOT how can the generation system model real astrophysics per se, but rather to quickly allow a GM to answer the above 5 questions with a reasonable chance of the system not being impossible.
Notes
Orbits is a vague term here, its used to mean ‘the orbit of an actual planet). Specifically, from what I’ve been able to gather, there are no orbit patterns as posited via (for instance) bodes law. I assume that planets exist, that the orbit the star, and that they don’t share the same orbit.
No attempt is made to provide actual distances within the system. Travel time between planets should be either prorated, based on the general values in CT (near world, near gas giant, etc) made up, or based on actual distances generated with a more detailed system.
Most of the planets other than the homeworld and explicit choices by the GM should NOT be rolled for using this system beyond what is provided, nor do I recommend using a vanilla LBB3 system to roll up the non-mainworlds; this is mainly intended to locate the homeworld in relation to the non-homeworld planets, locate the belts (for space opera danger and mining campaigns) and locate the Gas Giants (for fuel). The LBB system assumes that an inhabited Mainworld is likely what is being generated.
Stellar type generation will be added in scouts, I presume. This is designed to allow easy plug in.
Once a stellar type and size is determined, one can plug in the actual diameter into the 100d limit, and generate actual orbital distances from the star based on one’s favorite system. Plus, detailed climate(s) can be calculated.
Finally, the system allows existing generated worlds to be positioned in systems with some degree of likelihood. It also allows the system to influence the world generation for new planets.
The actual relationships of the orbits to each other are categorical, not continuous – there are no actual distances implied or generated. Just the order of planets outward from the sun.
First roll the jump shadow (JS) of the star: 1d6 orbits. This defines the 100d sphere in which jump is risky. As the star is unspecified, this is a relative measurement, not absolute.
Second, roll the number of significant planet/orbits for the star: 1d6+JS (alternately, since its not clear if a bigger star will have significantly more planets, just roll 2d6)
Again, this is not intended to capture all the planets/orbital bodies….just the ones significant to play and or spaceship movement, broadly defined. Locally significant planets for earth = Mercury out to Neptune, say.
Third, determine if there are any gas giants. Roll standard traveller check, or 2d6 7+ = yes for 1d6 gas giants.
Fourth ,determine Habitable zone. Roll 2d6. The low dice is the number of the first habitable orbit; the high dice is the orbit number of the first orbit outside the habitable zone. A tie means no planet in a hab zone .
The orbit defined by the high dice (or the tie) is also the first of the outer orbits. (see next item)
Fifth, roll two d6 for each orbit testing from the star out: .
For each orbit:
Boxcars in any orbit indicates a significant (close) companion star in the last orbit.
Pairs suggest a gas giant, if any exist (from above)
In the inner system, only paired ones (snakeyes) places a GG;
in the outer system any pair, or a total > half the orbit . (stop this step once you've allocated all the GGs)
( If you don’t place all the required Gas giants, add them to the outside of the system in new orbits (but inside any companion start, naturally)
Then, read the individual dice to identify the non GG occupant of that orbit.
For orbits in the inner region, look at the lower dice,
for outer region, read the high one :
1 small rock, (optionally of size 1-3)
2 large rock, (optionally of size 4+)
3 planetoid or belt (optionally of size 0-1)
4 small ice, (optionally of size 2-4)
5 Large ice (optionally of size 5+)
6 planetoid or belt. (optionally of size 0-1)
For orbits with GG , one can optionally use the number rolled to specify some particular significant moon (Saturn would have been generated by a 66 (the ring) or possibly a 22 (titan ?) . Yes, I’m assuming that inner GG will have a 11 – its optional, and possibly likely that no “significant” satellite exists.
Empty orbits are ignored.
Move to the next orbit.
Sixth Mainworld planetary generation. This only covers the Mainworld. One can either generate the planet now, which will influence its most appropriate place in the system , or preassign an orbit to it which will influence its creation.
Method I : Preassigned orbit.
Most homeworlds will be in the Hab zone. If no Hab zone, they will be in the last inner orbit. Optionally, test each inner zone orbit from the last one in: 1d6 3+ to be the orbit. If no inner zone or Hab Zone world is indicated, it will be in the first outerzone orbit; alternately, test each orbit going outwards: 3+ to be the orbit. Note: this is where the GG moon main worlds will be generated.
World creation effects:
Any inner orbit
-2 to the atmos roll.
-2 to Hydrosphere.
(optional) If first orbit (or optionally inner half of the inner zone)
-3 Atmos
-3 Hydro.
Any Hab zone
-1 Atmos
Any Outer zone:
(optional) +1 Size if size >4 (optionally, all taint atmospheres should be treated as type A)
Planet NOT in Hab zone, last inner orbit, or first outer orbit(optional).
-2 Population.
Now, using the above DMs, generate the homeworld.
Method II: Pregenerated world.
Generate the homeworld. as normal . Final orbit location is determined by planet atmosphere. This will replace the rolled orbit occupant (eg large rock, etc)
Atmos A+ need to be either in the last hab zone, or an outer zone orbit:
Start at the last hab zone orbit, and roll outwards for each non GG orbit : 1d6 roll of 3+ places the planet.
If it fails to place, it replaces the first Gas Giant in the Outer zone which moves to the last orbit (inside a companion)
Atmos 4-9 are placed in hab zones if available.
roll for each Hab zone orbit: d6 for 3+ places the planet. If the orbit contains a GG, the Mainworld is a moon of the GG.
if not in the hab zone, the last inner zone and then the first outer zone should be checked for d6 5+ ;
if this fails to place, it is a moon of the first Gas Giant in the Outer zone.
Atmos 0-3 can go in any orbit.
Start in the first hab zone orbit test outwards for 4+ on d6 to last hab zone;
Then last inner zone orbit and inwards; then first outer zone orbit outwards.
If it fails to place, it is a moon of the first Gas Giant in the Outer zone.
Size 0, 1 or S are generally moons or planetoids in a belt.
Initial placement is the first belt in the hab zone, or as a moon of the first planet in the hab zone (optionally, roll d6 for 2+ for each planet in the hab zone, working outward)
If not placed, choose the belt closest to the hab zone. If equidistant, take the one closest to the sun. Otherwise, test each gas giant going outwards for 3+ on d6 for it to be a moon.
If still not placed, roll for each non GG orbit starting from the first for 3+ on D6.
If STILL unplaced, it is the satellite of any companion, or in the last inner orbit.
If no belt, it is a moon of a planet in the hab zone
Size 1 can be in a belt (1-3) or an orbit (4-5) satellite of any world of type large or bigger orbit (6)
A stellar companion is always in the last orbit.
World generation:
Either pure LBB3, or the following:
Roll Starport
Roll size.
Roll Atmosphere type
Apply DMs as needed as above.
If final size >4, roll atmosphere as normal.
If <5, roll as 1d6 -7 + size. Any negative number = type 0; if 2+ treat as A.
If final Atm >A , -2 pop.
Roll Hydrosphere
Apply DMs as needed from above
Roll Population
Roll Govt
Roll Law Level
Determine Tech
THEN: Modify for starport type
If the population is below 6, there is the possibility that the Population, LL and Govt will be a reflection of the starport and immediate community, rather than the planet as a whole.
First note actual tech Pop, Govt and LL values as generated. If the UPP is altered by the starport, these will be the UPP used for the rest of the planet.
In general, the UPP won’t be changed from the CT data: however, the starport rating will provide a constant minimum set of values applicable to the starport as opposed to the planet.
If starport type D,
If population < 4 set population and LL to 2
If Tech < 7 set tech to 6
If starport type C,
If population < 4 set population and LL to 3
If Tech < 8 set tech to 7
If starport type B,
If population < 5 set population and LL to 4
If Tech < 9 set tech to 8
If starport type A ,
Population < 6 set population and LL to 5
If Tech < 10 set tech to 9
The above are the mimimum values for a given starport rating – they will be the no-frills, basic fill up and service ports of the region. Not all type A ports are alike, after all, and not all are Imperial Terra , Sylea or Trantor. Port values on planets that exceed the minimum values above are likely larger and fancier versions of that type of port facility.
Done, all with d6, no more than 2d dice per fact, and in just under 2 double sided pages.
Notes
The Sociological ratings (Govt, Pop, .LL) are assumed to be based on human transplants, all of which arrived within about the last 30-50000 years. Given that timespan, the age of the star, and thus the planets is irrelevant to the settlements colonist population. .
For native life, however, it is crucial. My thought would be to use the age of the star to determine likelihood of local life beyond the bare minimum needed to oxygenate the atmosphere.
Keep in mind the repeated use of the hedgeword "significant". There may be more planets, more moons, a farther companion, a system around the companion, etc. They just aren't useful at the moment.
Thanks especially to EDG (if he wants to be associated with this), and to the others on the socio-planetary thrashing forum :wink:
A modest proposal
I suggest that a problem lies in conceptualizing what the sector maps are intended for. Generally they are seen as maps, and used to describe the geography of the area in question.
Conceptually, a better approach to the problem is to view them as charts rather than maps. The difference is that a map is detail and accuracy oriented, and highly descriptive. A chart is only accuracy oriented when it is functional. A great example is the age of exploration portolan charts - they have very fiddly detail about coasts, the depths and hazards within a few miles of the coast, and where fresh water is available on the coast.....and nothing else, just white space, inland. They were for Navigators, not cartographers or scientists.
I think reframing the traveller system maps this way will help. The subsectors are already obvious functional abstractions, given the actual stellar density compared to the charted planets with starports. They are clearly a navigators reference: where are the ports the inhabited planets, the interesting stuff; and where are the shoals: red zones, and rifts.
From the viewpoint of a working navigator, It seems like you need a bare minimum of information other than the planet.
1. where is it (which orbit)
2. Are there other important ports insystem.
3. how big is the 100/10d limit for the star
(this actually should be priority 1, I imagine,)
4. since we may or may not be playing space opera, and optional consideration is where are the asteroid belts .
5. where are the gas giant(s), if any.
A trader may have one more question: are there useful resources off(main) planet ?
So, the question is, I feel, NOT how can the generation system model real astrophysics per se, but rather to quickly allow a GM to answer the above 5 questions with a reasonable chance of the system not being impossible.
Notes
Orbits is a vague term here, its used to mean ‘the orbit of an actual planet). Specifically, from what I’ve been able to gather, there are no orbit patterns as posited via (for instance) bodes law. I assume that planets exist, that the orbit the star, and that they don’t share the same orbit.
No attempt is made to provide actual distances within the system. Travel time between planets should be either prorated, based on the general values in CT (near world, near gas giant, etc) made up, or based on actual distances generated with a more detailed system.
Most of the planets other than the homeworld and explicit choices by the GM should NOT be rolled for using this system beyond what is provided, nor do I recommend using a vanilla LBB3 system to roll up the non-mainworlds; this is mainly intended to locate the homeworld in relation to the non-homeworld planets, locate the belts (for space opera danger and mining campaigns) and locate the Gas Giants (for fuel). The LBB system assumes that an inhabited Mainworld is likely what is being generated.
Stellar type generation will be added in scouts, I presume. This is designed to allow easy plug in.
Once a stellar type and size is determined, one can plug in the actual diameter into the 100d limit, and generate actual orbital distances from the star based on one’s favorite system. Plus, detailed climate(s) can be calculated.
Finally, the system allows existing generated worlds to be positioned in systems with some degree of likelihood. It also allows the system to influence the world generation for new planets.
The actual relationships of the orbits to each other are categorical, not continuous – there are no actual distances implied or generated. Just the order of planets outward from the sun.
First roll the jump shadow (JS) of the star: 1d6 orbits. This defines the 100d sphere in which jump is risky. As the star is unspecified, this is a relative measurement, not absolute.
Second, roll the number of significant planet/orbits for the star: 1d6+JS (alternately, since its not clear if a bigger star will have significantly more planets, just roll 2d6)
Again, this is not intended to capture all the planets/orbital bodies….just the ones significant to play and or spaceship movement, broadly defined. Locally significant planets for earth = Mercury out to Neptune, say.
Third, determine if there are any gas giants. Roll standard traveller check, or 2d6 7+ = yes for 1d6 gas giants.
Fourth ,determine Habitable zone. Roll 2d6. The low dice is the number of the first habitable orbit; the high dice is the orbit number of the first orbit outside the habitable zone. A tie means no planet in a hab zone .
The orbit defined by the high dice (or the tie) is also the first of the outer orbits. (see next item)
Fifth, roll two d6 for each orbit testing from the star out: .
For each orbit:
Boxcars in any orbit indicates a significant (close) companion star in the last orbit.
Pairs suggest a gas giant, if any exist (from above)
In the inner system, only paired ones (snakeyes) places a GG;
in the outer system any pair, or a total > half the orbit . (stop this step once you've allocated all the GGs)
( If you don’t place all the required Gas giants, add them to the outside of the system in new orbits (but inside any companion start, naturally)
Then, read the individual dice to identify the non GG occupant of that orbit.
For orbits in the inner region, look at the lower dice,
for outer region, read the high one :
1 small rock, (optionally of size 1-3)
2 large rock, (optionally of size 4+)
3 planetoid or belt (optionally of size 0-1)
4 small ice, (optionally of size 2-4)
5 Large ice (optionally of size 5+)
6 planetoid or belt. (optionally of size 0-1)
For orbits with GG , one can optionally use the number rolled to specify some particular significant moon (Saturn would have been generated by a 66 (the ring) or possibly a 22 (titan ?) . Yes, I’m assuming that inner GG will have a 11 – its optional, and possibly likely that no “significant” satellite exists.
Empty orbits are ignored.
Move to the next orbit.
Sixth Mainworld planetary generation. This only covers the Mainworld. One can either generate the planet now, which will influence its most appropriate place in the system , or preassign an orbit to it which will influence its creation.
Method I : Preassigned orbit.
Most homeworlds will be in the Hab zone. If no Hab zone, they will be in the last inner orbit. Optionally, test each inner zone orbit from the last one in: 1d6 3+ to be the orbit. If no inner zone or Hab Zone world is indicated, it will be in the first outerzone orbit; alternately, test each orbit going outwards: 3+ to be the orbit. Note: this is where the GG moon main worlds will be generated.
World creation effects:
Any inner orbit
-2 to the atmos roll.
-2 to Hydrosphere.
(optional) If first orbit (or optionally inner half of the inner zone)
-3 Atmos
-3 Hydro.
Any Hab zone
-1 Atmos
Any Outer zone:
(optional) +1 Size if size >4 (optionally, all taint atmospheres should be treated as type A)
Planet NOT in Hab zone, last inner orbit, or first outer orbit(optional).
-2 Population.
Now, using the above DMs, generate the homeworld.
Method II: Pregenerated world.
Generate the homeworld. as normal . Final orbit location is determined by planet atmosphere. This will replace the rolled orbit occupant (eg large rock, etc)
Atmos A+ need to be either in the last hab zone, or an outer zone orbit:
Start at the last hab zone orbit, and roll outwards for each non GG orbit : 1d6 roll of 3+ places the planet.
If it fails to place, it replaces the first Gas Giant in the Outer zone which moves to the last orbit (inside a companion)
Atmos 4-9 are placed in hab zones if available.
roll for each Hab zone orbit: d6 for 3+ places the planet. If the orbit contains a GG, the Mainworld is a moon of the GG.
if not in the hab zone, the last inner zone and then the first outer zone should be checked for d6 5+ ;
if this fails to place, it is a moon of the first Gas Giant in the Outer zone.
Atmos 0-3 can go in any orbit.
Start in the first hab zone orbit test outwards for 4+ on d6 to last hab zone;
Then last inner zone orbit and inwards; then first outer zone orbit outwards.
If it fails to place, it is a moon of the first Gas Giant in the Outer zone.
Size 0, 1 or S are generally moons or planetoids in a belt.
Initial placement is the first belt in the hab zone, or as a moon of the first planet in the hab zone (optionally, roll d6 for 2+ for each planet in the hab zone, working outward)
If not placed, choose the belt closest to the hab zone. If equidistant, take the one closest to the sun. Otherwise, test each gas giant going outwards for 3+ on d6 for it to be a moon.
If still not placed, roll for each non GG orbit starting from the first for 3+ on D6.
If STILL unplaced, it is the satellite of any companion, or in the last inner orbit.
If no belt, it is a moon of a planet in the hab zone
Size 1 can be in a belt (1-3) or an orbit (4-5) satellite of any world of type large or bigger orbit (6)
A stellar companion is always in the last orbit.
World generation:
Either pure LBB3, or the following:
Roll Starport
Roll size.
Roll Atmosphere type
Apply DMs as needed as above.
If final size >4, roll atmosphere as normal.
If <5, roll as 1d6 -7 + size. Any negative number = type 0; if 2+ treat as A.
If final Atm >A , -2 pop.
Roll Hydrosphere
Apply DMs as needed from above
Roll Population
Roll Govt
Roll Law Level
Determine Tech
THEN: Modify for starport type
If the population is below 6, there is the possibility that the Population, LL and Govt will be a reflection of the starport and immediate community, rather than the planet as a whole.
First note actual tech Pop, Govt and LL values as generated. If the UPP is altered by the starport, these will be the UPP used for the rest of the planet.
In general, the UPP won’t be changed from the CT data: however, the starport rating will provide a constant minimum set of values applicable to the starport as opposed to the planet.
If starport type D,
If population < 4 set population and LL to 2
If Tech < 7 set tech to 6
If starport type C,
If population < 4 set population and LL to 3
If Tech < 8 set tech to 7
If starport type B,
If population < 5 set population and LL to 4
If Tech < 9 set tech to 8
If starport type A ,
Population < 6 set population and LL to 5
If Tech < 10 set tech to 9
The above are the mimimum values for a given starport rating – they will be the no-frills, basic fill up and service ports of the region. Not all type A ports are alike, after all, and not all are Imperial Terra , Sylea or Trantor. Port values on planets that exceed the minimum values above are likely larger and fancier versions of that type of port facility.
Done, all with d6, no more than 2d dice per fact, and in just under 2 double sided pages.
Notes
The Sociological ratings (Govt, Pop, .LL) are assumed to be based on human transplants, all of which arrived within about the last 30-50000 years. Given that timespan, the age of the star, and thus the planets is irrelevant to the settlements colonist population. .
For native life, however, it is crucial. My thought would be to use the age of the star to determine likelihood of local life beyond the bare minimum needed to oxygenate the atmosphere.
Keep in mind the repeated use of the hedgeword "significant". There may be more planets, more moons, a farther companion, a system around the companion, etc. They just aren't useful at the moment.
Thanks especially to EDG (if he wants to be associated with this), and to the others on the socio-planetary thrashing forum :wink:
. I love the Onion!
