Mgt Scout mainworld cartography help

[The Chef]

Hi all,

i'm being dense but i cannot figure out what the instructions are telling me on page 92.

Now i don't want an essay on how unrealistic it is, or how other people do it, i just want someone to tell me line for line which bits mean what and what i should be rolling.

cos i'm a confussed chef.

Thanks

Chef....

 

[rust]

a) Determine Jump Shadow (JS) with 1d6
b) Determine total of orbits / planets with 1d6+JS
c) Determine the 3 Zones with 2d6, low dice = last inner orbit,
high dice = first outer orbit, anything in between is habitable
zone

Now you have the total number of orbits and know where the
jump shadow and the 3 zones of the system are.

The next step (5. in the book) is done for every single orbit to de-
termine what is in this orbit, gas giant or planet, and what kind of it.
I think it is not that difficult to understand, so I do not repeat it here
- otherwise just ask again.

Once you have done (5.) for all orbits, you move to step (6.), the
mainworld of the system.
There are not many die rolls involved (if any), the book only descri-
bes some optional methods for the placement of the mainworld of
the system, based upon the UWP of the planet.

If this does not help at all, please tell me where exactly you have the
problem, and I will try to find a solution. :wink:

 

[The Chef]

c) Determine the 3 Zones with 2d6, low dice = last inner orbit,
high dice = first outer orbit, anything in between is habitable
zone

Thanks Rust

so lets say that i roll 1 for JS 3 for significant orbits so i have 4 orbits,

Now i roll 2d6 and get a 3 and a 6. So does that mean i have 3 orbits in my inner zone of which 1 may contain something, 3 in my Habitable (the difference between 3 and 6) with 2 containing something, and 6+ for the outerzone of which 1 orbit can contain something.

and as i've already prerolled my planets i follow the little note at the bottom of P92 and i suppose i swap out one of the planets i may have assigned to the correct orbit?

also the Jump shadow.. i know its 100d's from the main star, so i take it that number on the d6 is the number of dimensions is a safe jump. Would that mean that the bigger the shadow the bigger the star?

Chef

 

[rust]

If I get it right (no guarantee for that ...):

You have rolled 1 for the jump shadow, so 1 of the system's orbits is
within the jump shadow.
Then you have rolled 3 for the other significant orbits, which gives the
system a total of 4 significant orbits.

With a 3 and a 6 you have determined the system's zones: the 3 orbits
(not necessarily significant ones) 1, 2 and 3 are in the inner zone, orbit
6 is the first orbit of the outer zone - and therefore the orbits 4 and 5
are in the habitable zone.

There is a minor problem with your dice results, because your system
has a total of at least 6 orbits according to the calculation of the zones,
but only 4 significant orbits to fill with something noteworthy.
I think it is up to you how to treat this, either creating something for
the two "surplus" orbits, or leaving them as empty orbits.

The way you place your mainworld is completely up to you, the book gi-
ves some options as examples, but I would just put it where I think it
fits best for my game.

"The bigger the jump shadow, the more massive the star" will usually be
true, but remember that this system only gives the number of orbits in-
side the jump shadow - it could be a small star with very tight orbits or
a big star with more space between orbits.

 

[EDG]

"The bigger the jump shadow, the more massive the star" will usually be true, but remember that this system only gives the number of orbits inside the jump shadow - it could be a small star with very tight orbits or a big star with more space between orbits.

If a planet is inside a star's jump shadow, it's usually because it's a K or M V star and the habitable zone (containing the planet) is very close to the star. For an M V star the shadow will extend to between about 0.2-0.3 AU, for a K V star it'll be around the 0.4-0.7 AU mark, and for a G V star it'll be around 0.8 to 1.1 AU (IIRC Venus would be inside Sol's jump shadow, but Earth is outside).

Giant stars are the ones with the huge jump shadows - Antares' jump shadow is 1000AU in diameter!

 

[The Chef]

Thanks Rust,

was trying to work it all out earlier and was getting very confussed.

still getting to grips with star mapping and planet generation. I do like the way traveller deals with this in a highly simplistic yet detailed way. but just couldn't get my head round the details presented in scout.

chef

 

[captainjack23]

If I get it right (no guarantee for that ...):

You have rolled 1 for the jump shadow, so 1 of the system's orbits is
within the jump shadow.
Then you have rolled 3 for the other significant orbits, which gives the
system a total of 4 significant orbits.

With a 3 and a 6 you have determined the system's zones: the 3 orbits
(not necessarily significant ones) 1, 2 and 3 are in the inner zone, orbit
6 is the first orbit of the outer zone - and therefore the orbits 4 and 5
are in the habitable zone.

There is a minor problem with your dice results, because your system
has a total of at least 6 orbits according to the calculation of the zones,
but only 4 significant orbits to fill with something noteworthy.
I think it is up to you how to treat this, either creating something for
the two "surplus" orbits, or leaving them as empty orbits.

The way you place your mainworld is completely up to you, the book gi-
ves some options as examples, but I would just put it where I think it
fits best for my game.

"The bigger the jump shadow, the more massive the star" will usually be
true, but remember that this system only gives the number of orbits in-
side the jump shadow - it could be a small star with very tight orbits or
a big star with more space between orbits.

Yes, I think you have it right, and thanks for stepping up to explain, rust.

The stars Jump shadow covers the first orbit; the habitable zone starts with orbit 4; there are not necessarily any more than 4 significant orbits , total.
So, generally, the mainworld would be in orbit 4 -unless you want to put it elsewhere !

In particular, and this wasn't addressed to save space, and probably should have been, non "earthy"mainworlds, particularly with very thin and below atmos, can be placed anywhere. My assumption was that the hab zone was generally a likely place for the closest match to an earth type in that system, even if it wasn't very close (such as mars) and for variety of reasons which would still be useful even with a less habitable planet planet: liklihood of easy access to liquid(ish) water, solar power vs solar radiation balance, outside of jump shadow, system resource access.

The only other issue is if the planet has a GG or not, which is determined as per the main rules.

The non-significant orbits would be ones I'd either just leave unfilled, or would put any required gas giant into -in this case, orbit 6; unless you wanted the oddity of a GG in the habitable zone, in which case it would be orbit 5 -and one could make the mainworld a moon of it, if you wanted.

Really, I wish I'd had one more editing pass at it -I think that I erred on the side of terse......ah well. It does what it does.

So, is that helpful Chief ? Feel free to ask more questions -I'm sure if you found some, others have too.

 

[captainjack23]

"The bigger the jump shadow, the more massive the star" will usually be true, but remember that this system only gives the number of orbits inside the jump shadow - it could be a small star with very tight orbits or a big star with more space between orbits.

Both the mass/shadow assumption, and the caveat are what I worked from. Interestingly, expert opinion seems to suggest that stellar size is not easily or reliably related to number of planets -or in this case, the orbits.

If a planet is inside a star's jump shadow, it's usually because it's a K or M V star and the habitable zone (containing the planet) is very close to the star. For an M V star the shadow will extend to between about 0.2-0.3 AU, for a K V star it'll be around the 0.4-0.7 AU mark, and for a G V star it'll be around 0.8 to 1.1 AU (IIRC Venus would be inside Sol's jump shadow, but Earth is outside).

Giant stars are the ones with the huge jump shadows - Antares' jump shadow is 1000AU in diameter!

I should note that the system as published says nothing about the stellar type or even the spacing of the orbits; not do I recommend attempting to reverse engineer the stellar type from the information generated. If that's the level of detail needed, I'd recommend either waiting for the MGT world builders book, or looking at First in from GURPS traveller, or even Interstellar Wars (if I can be pardoned for discussing a non-MGT compliant product ).

 

[The Chef]

Thanks Rust, EDG and Captainjack,

i imagine a lot of people would look at that page and get it straight away but i tend to struggle with numbers and normally i handwave over the whole science thing.

But i'm aiming for at least a touch of detail with this new campaign, and where planets are in a system will matter a lot to my players.

thanks

Chef

 

[Rikki Tikki Traveller]

I use the TEMPERATURE roll during UWP creation to place the mainworld. If the mainworld has a Roasting temperature, it is inside the Habitable Zone. If it is Frozen, it is Outside the Habitable Zone.

How far inside or outside depends on how nasty I want the place to be.