Question on World Creation

[Tay]

Quick question (I Should know this but have a mental block).

A hydrographic percentage is obtained by rolling 2D-7 and adding the planet’s atmosphere, some atmospheres use the modifier listed below instead.
Size 0 or 1: Hydrographic 0
Atmosphere 0, 1, A, B or C: DM-4

Question : if Atmosphere 0, 1, A, B or C is the roll then 2D-7 + Atmos & then DM-4

or if Atmosphere 0, 1, A, B or C it's then 2D + Atmos and then DM-4

or Atmosphere 0, 1, A, B or C its then 2D & DM-4

Cheers in advance

 

[OrdosMalleus]

The "raw" Hydrographics roll is 2d6-7.

If Size is 0 or 1, then hydro = 0
If Atmo is 0, 1, A, B, or C then the modifier is -4 instead of -7.
Otherwise, add the atmo score to offset the -7.

That's how I read it, at least.

 

[Geir]

The intent is 2D-7 and then DM-4 for 0,1,A,B,C to prevent exotic plus from becoming fluid covered worlds.
It probably should also be for D and E for similar reasons, but that's not RAW.
I forget which Traveller version has Hydrographics as Size-7 instead of Atmopshere-7. I always liked basing it on size better, but that's not RAW either. It would work better for those D and E atmospheres, though.

 

[Tay]

Thanks Geir.

Mongoose 1st ed did it with size then errata was done .

T4 and Cepheus do it that way too.

 

[Geir]

The intent is 2D-7 and then DM-4 for 0,1,A,B,C to prevent exotic plus from becoming fluid covered worlds.
It probably should also be for D and E for similar reasons, but that's not RAW.
I forget which Traveller version has Hydrographics as Size-7 instead of Atmopshere-7. I always liked basing it on size better, but that's not RAW either. It would work better for those D and E atmospheres, though.

(Hey Matthew, if you're watching, probably want to remove the word 'instead' from the hydrographic text for clarity's sake ... and make 'modifier' plural)

 

[AnotherDilbert]

Some of the confusion probably comes from:

Hydrographic percentage is obtained from a two dice throw, with an automatic DM of –7 applied.
A further DM of + planetary size is also applied (a planetary size of 0 or 1 indicates an automatic result of 0).
If planetary atmosphere is 0, 1, or greater than 9, apply a DM of –4.

vs.

Hydrographic Percentage (2D-7+atmosphere;
if size 0 then hydrographics 0,
if atmosphere 0, 1, or A+, then apply DM -4)

LBB6 reverted to:

Hydrographics: Determine hydrographics with 2D - 7 + size.
...
If atmosphere 1- or A +, then DM - 4.

Errata and the current bible says:

Hyd= Flux [2D-7] + Atm + Mods. Max= A.
If Siz <2, Hyd =0
If Atm <2 or Atm >9, DM - 4.

In all cases the DM -4 is in addition to any other DMs.

 

[Geir]

Thanks. That's a great summary of the back and forth. I definitely think the DM-4 should apply to all atmospheres above 9.
But then again, I also invoke Rule 0 and use size and not atmosphere, but then further modify the result for small size (a reverse McKinney - from what I can tell he made the size bigger to explain the atmosphere). What can I say, I'm a rebel.

 

[AnotherDilbert]

But then again, I also invoke Rule 0 and use size and not atmosphere, but then further modify the result for small size (a reverse McKinney - from what I can tell he made the size bigger to explain the atmosphere).

From pure prejudice I would use atmosphere. I guess oceans would boil away without any atmosphere?

Or rather, if there are oceans, some of the fluid would boil away to form an atmosphere? Few, if any, liquids stay liquid in vacuum, I believe. Hence, if there is no atmosphere, there are no oceans.

 

[Geir]

But then again, I also invoke Rule 0 and use size and not atmosphere, but then further modify the result for small size (a reverse McKinney - from what I can tell he made the size bigger to explain the atmosphere).

From pure prejudice I would use atmosphere. I guess oceans would boil away without any atmosphere?

Or rather, if there are oceans, some of the fluid would boil away to form an atmosphere? Few, if any, liquids stay liquid in vacuum, I believe. Hence, if there is no atmosphere, there are no oceans.

Treat the results as ice if it's atmosphere 0 or 1. That's even RAW, so it works.

 

[AnotherDilbert]

Treat the results as ice if it's atmosphere 0 or 1. That's even RAW, so it works.

Might work for Trace atmosphere, but in vacuum even ice will sublimate away:

The bottom of the graph shows very low atmospheric pressure.

There might be some ice deposits in perpetual darkness, but even a little sunshine or any other heat would gasify the ice to form an atmosphere?