[Chroniques Galactiques] Générateur aléatoire de systèmes stellaires et espèces intelligentes (En Anglais) 18

Voilà, comme évoqué dans un autre sujet, je vous colle brut de fonderie une aide de jeu que j'avais trouvé il y a une vingtaine d'années, et que j'ai trouvé tout simplement géniale. Je laisse le nom de l'auteur, car ce n'est pas mon travail, bien entendu.
 
Je pense qu'elle serait très utile pour Chroniques Galactiques.
Par contre, c'est en Anglais, c'est assez aride (à l'époque sur Internet on ne s'embarassait pas trop de la mise en forme), et c'est basé sur les connaissance scientifiques de l'époque (en 1995 la première exoplanète venait d'être découverte, et on considérait encore Pluton comme une planète !)
 
 

From: Ross Smith
Newsgroups: rec.games.frp.misc
Subject: Planet generation system (part 1/2)
Date: 17 Dec 1995 11:29:05 GMT
I've finally got around to updating the planet generation system I first
posted here a couple of years ago. Besides minor changes to the star and
planet mechanics, I've added systems for generating colonies and
intelligent species.
I'm working on a set of programs for automatic generation of stars,
planets, colonies, and aliens; they should be ready early in the new year.
An HTML version is available; email me if you want it.
---------------------------------------------------------------------------
PLANET GENERATION SYSTEM
------------------------
Version 2.0 (4-Dec-95)
Copyright 1995 by Ross Smith

CONTENTS
--------
1. Introduction
2. Star Systems
3. Planetary Systems
4. Earthlike and Marginal Planets
    4.1. Physical Details
    4.2. Biological Details
    4.3. Special Features
    4.4. Examples
5. Colonisation
    5.1. Sector Characteristics
    5.2. Planet Quality
    5.3. Colonies
    5.4. Examples
6. Technology
7. Intelligent Life
    7.1. Physical Description
    7.2. Special Features
    7.3. Psychological Profile
    7.4. Technology
    7.5. Examples

1. INTRODUCTION
---------------
This is a reasonably quick and simple system for generating complete
planetary systems in rough detail, and the most interesting planets in
somewhat greater detail. It also includes a system for generating
intelligent life forms. It isn't tied to any particular game mechanics, and
should be usable with any SFRP system.
I designed it because I've never been very impressed by the planet
generation schemes in most SF role-playing games, which are usually either
too unrealistic or too complicated (or, frequently, both). I wanted a
scheme that was simple enough to generate systems fairly quickly, while
still being designed by someone who knew one end of a Hertzsprung-Russell
diagram from the other (hint: neither end is likely to have anything
resembling Earth orbiting it).
You will need some six-sided and ten-sided or twenty-sided dice (or, of
course, a computer with a good random number function). I assume you're
familiar with the usual dice notation (so you know what something like
"2D6+3" means). This system requires rolls on D6, D10, D20, and D100.
Unless otherwise stated, all results of less than zero should be counted as
zero, and all fractional results should be rounded to the nearest whole
number (round halves upwards).
This file is copyright 1995 by Ross Smith. It may be distributed and
archived freely, provided no changes are made. Comments can be mailed to me
at the address above, or posted to rec.games.frp.misc.
An HTML version is available; email me if you want it.
Version history:
1.0 (1-Aug-93): Original version.
1.1 (2-Oct-93): Expanded star type table; orbit periods added; various
minor changes.
1.2 (30-Oct-94): Minor revisions.
2.0 (4-Dec-95): Minor revisions to star and planet system; added sections
on colonisation and intelligent life.

2. STAR SYSTEMS
---------------
In the local region of the Galaxy, there is about one star system per 600
cubic light-years. I suggest using cube-shaped sectors either 25 or 50
light-years on a side. A 25 light-year sector has 8D6-2 star systems
(average 26); a 50 light-year sector has 6D20+145 systems (average 208;
more appropriate to generation by a computer program than by hand). Place
the systems at random within the sector (roll D100/4 or D100/2 for each of
the X, Y, and Z coordinates).
To find the number of stars in a system, roll D100 on the following table:
    D100   Stars
    -----  -----
    1-40   1
    41-90  2
    91-99  3
    100    4
Stars are classified into seven "spectral types", based on their
temperature and colour. The types are O (blue), B (blue-white), A (white),
F (yellow-white), G (yellow), K (orange), and M (red); astronomers use the
mnemonic "Oh, Be A Fine Girl, Kiss Me" to remember the sequence. The seven
types are each divided into ten subclasses, indicated by a digit from 0 to
9 after the spectral type (except type O, which is normally divided only
into subclasses 5 to 9). The Sun, for example, is type G2.
A Hertzsprung-Russell diagram is a plot of stars with spectral type on the
horizontal axis and luminosity on the vertical axis. The majority of stars
fall into the "main sequence", which runs roughly diagonally, from bright,
blue-white O-type stars at the top left of the diagram to dim M-type red
dwarfs at the bottom right, with yellow dwarfs like the Sun falling almost
exactly in the middle. Other types of stars are above or below the main
sequence.
Red giants (indicated by a "g" prefix on the spectral type, e.g. "gM5") and
supergiants (indicated by a "c" prefix, e.g. "cK0") are late stages in the
life cycle of massive stars. White dwarfs (indicated by a "D" prefix, e.g.
"DA"), much dimmer than most main sequence stars, are the final stage in
the evolution of most stars. The most massive stars will end up as neutron
stars or black holes (these have no spectral types; the tables below use
"NS" and "BH" to represent them).
For each star in a system, roll D100 (one to three times) on the following
table, to get the general description and the specific spectral class of
the star. A subclass number should also be generated for main sequence and
giant stars (white dwarfs are not usually given a subclass).
The stars in a system should be listed in descending order of luminosity.
Take the basic groups in order (supergiants, giants, main sequence, white
dwarfs, neutron stars, black holes); within each group, list stars in order
of spectral type.
    First  Second  Third   Basic          Spectral  Subclass
    D100   D100    D100    type           class
    -----  ------  ------  -------------  --------  ---------
    1      1       1-10    Supergiant     cB        D10-1
    ...    ...     11-20   ...            cA        D10-1
    ...    ...     21-40   ...            cF        D10-1
    ...    ...     41-60   ...            cG        D10-1
    ...    ...     61-80   ...            cK        D10-1
    ...    ...     81-100  ...            cM        D10-1
    ...    2-5     --      Giant          gF        D10-1
    ...    6-10    --      ...            gG        D10-1
    ...    11-55   --      ...            gK        D10-1
    ...    56-95   --      ...            gM        D10-1
    ...    96-99   --      Neutron star   NS        --
    ...    100     1-20    Black hole     BH        --
    ...    ...     21-100  Main sequence  O         (D10/2)+4
    2      --      --      ...            B         D10-1
    3-4    --      --      ...            A         D10-1
    5-8    --      --      ...            F         D10-1
    9-15   --      --      ...            G         D10-1
    16-30  --      --      ...            K         D10-1
    31-93  --      --      ...            M         D10-1
    94     --      --      White dwarf    DB        --
    95-96  --      --      ...            DA        --
    97-98  --      --      ...            DF        --
    99     --      --      ...            DG        --
    100    --      --      ...            DK        --
Many astronomical references use a more detailed system of "luminosity
classes", which run from I (supergiants) to VII (white dwarfs). This level
of detail is probably unnecessary for gaming. If you're using a star
catalogue that uses this system, you can convert the full luminosity
classes to the broad classes I've used here using the following table.
    Luminosity class               Description
    -----------------------------  -------------
    I                              Supergiant
    O-A II, F II-III, G-M II-IV    Giant
    O-A III-VI, F IV-VI, G-M V-VI  Main sequence
    VII                            White dwarf

3. PLANETARY SYSTEMS
--------------------
Refer to the following table to generate the number of planets for each
star. First determine whether there are any planets; for multiple star
systems, roll only once for the whole system, using the spectral type of
the primary star. If the result is affirmative, generate the number of
planets for each star, based on the star's own spectral type.
    Star                     Spectral  Probability  Number of
    type                     class     of planets   planets
    -----------------------  --------  -----------  ---------
    Giant/supergiant         All       10%          D6
    Main sequence            O-B       10%          D10
    ...                      A         50%          D10
    ...                      F-G       99%          2D6+3
    ...                      K         99%          2D6
    ...                      M         50%          D6
    White dwarf              All       10%          D6/2
    Neutron star/black hole  All       5%           D6/2
Planetary systems are divided into three zones; different types of planet
will tend to form in each zone. Zone A is the inner or hot zone; zone B is
the intermediate or life zone; and zone C is the outer or cold zone (in our
system, Mercury and Venus are in zone A, Earth and Mars are in zone B, and
the asteroids and outer planets are in zone C). The following table
indicates which planets are in each zone for main sequence, giant, and
supergiant stars; all planets of white dwarfs, neutron stars, and black
holes are considered to be in zone C.
    Total    Planets in   Planets in   Planets in
    planets  zone A       zone B       zone C
    -------  -----------  -----------  ----------
    1-3      --           Planet 1     Planets 2+
    4-5      Planet 1     Planet 2     Planets 3+
    6-7      Planet 1     Planets 2-3  Planets 4+
    8+       Planets 1-2  Planets 3-4  Planets 5+
At this point, if the star is a member of a multiple system, remove the
outermost D6+1 planets (this may leave the star with no planets). Determine
the planetary zones before deleting planets.
For each planet, three parameters are determined: type, size, and number of
moons. Roll D100 and refer to the following table for planet type, then
generate the size and moons.
    Planet         D100                    Diameter      Number
    type           Zone A  Zone B  Zone C  (km)          of moons
    -------------  ------  ------  ------  ------------  --------
    Asteroids      1-5     1-5     1-5     --            --
    Giant          --      6-8     6-75    3D6x10000     2D10
    Rock           6-60    9-40    76-80   D10x1000      D6xD6/10
    Cold           --      --      81-90   D10x1000      D6xD6/10
    Desert         61-70   41-60   91-95   (2D6+2)x1000  D6xD6/10
    Hostile [*1]   71-100  61-80   96-100  (3D6+1)x1000  D6xD6/10
    Marginal [*2]  --      81-90   --      (2D6+5)x1000  D6xD6/10
    Earthlike [*2] --      91-100  --      (2D6+5)x1000  D6xD6/10
    [*1: Count as "cold" if the star is a white dwarf, neutron star, or
    black hole.]
    [*2: Count as "hostile" if the star is anything other than a main
    sequence star of type F, G, or K.]
Asteroids: A collection of rocks that never combined to form a planet.
Usually there will be a handful of large asteroids a few hundred kilometres
across, and a vast number of smaller objects.
Giant: A huge planet consisting mainly of hydrogen, ranging from ten to a
thousand times the Earth's mass. Example: Jupiter.
Rock: A small, rocky planet with no atmosphere. Example: Mercury.
Cold: A small planet with no atmosphere, composed mainly of ice; found only
in the outer part of a system. Example: Pluto.
Desert: Comparable in size to Earth, but with a barren surface and a thin,
inert atmosphere. Example: Mars.
Hostile: Comparable in size to Earth, with an atmosphere containing no (or
a negligible amount of) oxygen, but possibly with some other active
component. Hostile planets may occasionally have native life forms, but
they will be based on a very non-Earthlike biochemistry. Example: Venus.
Marginal: Almost Earthlike, with oxygen in the atmosphere, but with some
serious problem that makes it an unpleasant place to live, such as very
high or low temperature, atmospheric pressure, or oxygen level; traces of
some toxic gas in the atmosphere; dangerous volcanic activity; or high
radiation level. No examples in our solar system.
Earthlike: Oxygen atmosphere, temperatures not too far outside the human
comfort zone, and a reasonably stable surface. Note that the presence of
oxygen in the atmosphere necessarily implies the presence of life (oxygen
is too reactive to occur in large amounts from geological processes alone,
and would disappear in a relatively short time if life were to become
extinct). Example: Earth.
The details of a system's planets can be conveniently written using the
initial letter of the planet type, the size in thousands of kilometres, and
a dot followed by the number of moons, if any. Asteroid belts are simply
indicated by an "A" with no numbers (and are not counted towards the
"official" number of planets). Use slashes to mark the zone boundaries.
Here are some examples, using our solar system and an imaginary one
generated for Alpha Centauri.
Sun
    G2, 9 planets: R5 H12 / E13.1 D7.2 / A G143.16 G121.18 G51.15 G51.8 C2.1
Alpha Centauri
    A: G2, 6 planets: R9.3 H8 / H10 M15.2 / C5.1 G110.9
    B: K0, 2 planets: R10.2 / H8 /
    C: M5, 1 planet: H17.1 / /

4. EARTHLIKE AND MARGINAL PLANETS
---------------------------------
4.1. PHYSICAL DETAILS
Generate a planet's orbit period using the table below, dependent on the
spectral type of its sun. If there are two Earthlike or marginal planets
orbiting the same star, generate two periods and assign them in the correct
order (the inner planet, obviously, gets the shorter period). If the outer
period is less than 25% more than the inner one, generate both of them
again.
    Star type  Orbit period
               (Earth days)
    ---------  -------------
    F0-F4      (2D100x3)+600
    F5-F9      (2D100x2)+400
    G0-G4      2D100+270
    G5-G9      2D100+150
    K0-K4      D100+120
    K5-K9      D100+70
To find the planet's rotation period, roll D100, add 10 for each moon, add
10 if the planet orbits a K-type star, and refer to the following table.
    Result   Rotation
    -------  ------------
    1-65     D20+9 hours
    66-90    D20+20 hours
    91-98    D10 days
    99-103   D100 days
    104-150  D10 days
Roll D6/2+3 (keep fractions, don't round) for the planet's density in grams
per cubic centimetre. Multiply diameter by density and divide by 70000 to
calculate the surface gravity in Earth gravities (round to the nearest
0.1).
Roll 2D6-4 for Earthlike planets, or D10+D6-6 for marginal planets, and
multiply by 5 to find the average surface temperature in degrees Celsius
(negative numbers should be retained here, not counted as zero). If a star
has two planets in zone B and both of them are Earthlike or marginal, make
sure the temperatures are in the right order; the outer planet should have
a temperature no higher than the inner one (greenhouse effects and similar
phenomena can affect a planet's temperature, but not by all that much on a
planet with an approximately Earthlike atmosphere). If the outer planet's
temperature comes out higher, either swap them around (if the planets are
both Earthlike or both marginal) or generate both temperatures again (if
there is one of each).
Use the following table to determine the proportion of the planet's surface
covered by dry land, water, and ice. Roll dice for the water and ice areas
(count less than zero as zero, more than 100% as 100%); the land area is
whatever remains. If the water and ice areas add up to more than 100%, roll
both again.
    Average       Water        Ice
    temperature   area         area
    ------------  -----------  ------------
    -20 to -10 C  (D10-5)x5 %  (D10+10)x5 %
    -5 to 5 C     (D20-5)x5 %  D10x5 %
    10 to 20 C    (5D6-8)x5 %  (D6-2)x5 %
    25 to 35 C    (5D6-8)x5 %  (D6-3)x5 %
    40 to 50 C    (5D6-8)x5 %  (D6-4)x5 %
If the land and water percentages are both greater than zero, the oceans
are assumed to be salt water (unless the planet has the "freshwater oceans"
special feature; see below). If the land percentage is zero, any oceans
will be fresh water (salt reaches the ocean through runoff from the land;
if there's no land, there's no salt).
A planet's mineral resources are measured on an arbitrary scale, running
from 1 (worst) to 100 (best). The Earth is rated 80, fairly high, because
of its high density (implying a relatively high ratio of metal to rock),
and its active volcanic and tectonic processes (which carry minerals from
deep in the interior to the surface). A planet's mineral resources rating
is generated by the formula:
    Minerals = (Diameter / 500) + (Density x 10) + (D100 / 2) - 45

4.2. BIOLOGICAL DETAILS
Roll D100 on each of the following tables to determine the evolutionary
level of the local life forms, and their chemical basis.
    D100                  Level of development
    Earthlike  Marginal
    ---------  ---------  --------------------------------------------------
    --         1          No life
    1-10       2-30       I: Single-celled organisms only
    11-20      31-45      II: Simple invertebrates and plants (in seas)
    21-30      46-60      III: Advanced invertebrates and plants (on land)
    31-40      61-75      IV: Simple vertebrates (fish, amphibians)
    41-100     76-100     V: Advanced vertebrates (reptiles, birds, mammals)
If you get the "No life" result, life must have become extinct fairly
recently by geological standards, or the oxygen in the atmosphere would
have combined with surface materials and disappeared (it's difficult to say
how long this would take -- perhaps a few million years). The extinction
was probably caused by nuclear war or an astronomical disaster such as an
asteroid strike or a nearby supernova.
    D100                 Biochemistry
    Earthlike  Marginal
    ---------  --------  ----------------
    1-20       1-5       Earthlike
    21-80      6-60      Protein-based
    81-100     61-99     Carbon-based
    --         100       Non-carbon-based
For simplicity, the many possible varieties of biochemistry are divided
into four broad classes.
Earthlike: Essentially the same chemical basis as Earth's life forms, with
only small differences, if any. Plants and animals with Earthlike
biochemistry can often be safely eaten by humans (and vice versa).
Protein-based: Similar to Earth life in its basic chemical components, but
with enough differences to make the biochemistries incompatible. Life of
this type will nearly always be inedible, and frequently poisonous, to
humans.
Carbon-based: Based on the same elements as Earth life, but arranged in
very different compounds. Always inedible, and usually extremely poisonous.
Non-carbon-based: Completely different to Earth's biochemistry in every
way. Invariably poisonous. Very rare, at least on anything resembling an
Earthlike planet.

4.3. SPECIAL FEATURES
There is no such thing as a typical Earthlike planet; every world is
unique. To reflect this, some Earthlike or marginal planets will have one
or more "special features" that are not covered by the usual planetary
parameters. Roll a D100 three times on the following table to determine
what the features are. If you get the same result (other than "No special
feature") twice, roll again.
Most features are restricted to planets with certain properties (for
example, the "Freshwater oceans" feature obviously requires an ocean
percentage greater than zero), or are incompatible with certain other
features (for example, a planet can't have both "High inclination" and "No
seasons"). Some features are sufficiently hazardous to human health that
they are restricted to marginal planets. See the detailed descriptions
below for explanations of the incompatibilities and prerequisites. If you
get an result incompatible with what you already know about the planet,
roll again.
    D100    Special feature
    ------  -------------------------
            Astronomical features
    1           Eccentric orbit
    2           High inclination
    3           High tides
    4           Meteor storms
    5           No seasons
    6           Rings
            Geological features
    7           Radiation hazard
    8           Rugged terrain
    9           Volcanic activity
            Hydrographic features
    10          Freshwater oceans
    11          Many islands
    12          Poisonous oceans
    13          Swampy surface
            Atmospheric features
    14          Cloud cover
    15          Toxic gas
    16          Unstable climate
    17          Very dense atmosphere
    18          Very thin atmosphere
            Biological features
    19          Intelligent life
    20          Semi-intelligent life
    21          World forest
            Archaeological features
    22          Ancient artifacts
    23-100  No special feature

ASTRONOMICAL FEATURES
Eccentric orbit: The planet's orbit is highly elliptical, producing
extremes of temperature at closest approach (periastron) and furthest
distance (apastron). Incompatible with "No seasons".
High inclination: The planet's axis is tilted by more than 45 degrees,
producing extreme temperature differences between summer and winter.
Incompatible with "No seasons".
High tides: A large, close moon or sun produces extremely high tides.
Requires either a K-type sun or at least one moon, and both land and water
areas to be non-zero.
Meteor storms: The planet suffers frequent meteor storms, often including
large asteroid or comet impacts, making the planet's surface a dangerous
place. Marginal planets only.
No seasons: The planet has close to zero axial inclination and orbital
eccentricity, so there are no seasonal effects. Requires a single star;
incompatible with "Eccentric orbit" or "High inclination".
Rings: The planet has a natural ring system.

GEOLOGICAL FEATURES
Radiation hazard: Radioactive minerals, or fallout from a nuclear war,
create a significant radiation hazard over large parts of the planet.
Marginal planets only.
Rugged terrain: The planet's land surface is almost entirely covered with
mountains and rough, rocky terrain, with practically no flat plains or
rounded hills. Requires a non-zero land area; incompatible with "Swampy
surface".
Volcanic activity: The planet has many active volcanos, enough to make life
dangerous over a large part of its surface. Marginal planets only.

HYDROGRAPHIC FEATURES
Freshwater oceans: The planet's oceans have very little salt in them,
either because they're geologically young or because some life form has
affected their composition. Requires both the land and water areas to be
non-zero. If the land area is zero and the water area is non-zero, this
feature is automatically present, independently of the special feature
rolls.
Many islands: The planet's land surface is broken up into a large number of
small islands, with no large continents. Requires both the land and water
areas to be non-zero.
Poisonous oceans: The oceans contain some contaminant or (more likely) life
form that makes the planet's sea water (and probably some of its fresh
water) poisonous to humans. Marginal planets only; requires a non-zero
ocean area.
Swampy surface: Most of the planet's land surface is low-lying and covered
with swamps, marshes, mud, quicksand, and so on. Requires a non-zero land
area; incompatible with "Rugged terrain".

ATMOSPHERIC FEATURES
Cloud cover: The planet has a permanent cloud cover over its entire
surface; it probably rains most of the time. Requires a temperature greater
than zero; incompatible with "Very thin atmosphere".
Toxic gas: The atmosphere contains some gas which is poisonous to humans,
making filter masks necessary. Marginal planets only.
Unstable climate: The climate undergoes severe and unpredictable changes
from year to year.
Very dense atmosphere: The atmosphere is dense enough to be unbreathable
without special respirator equipment, except perhaps on very high
mountains. Marginal planets only; incompatible with "Very thin atmosphere".
Very thin atmosphere: The atmosphere is too thin to breathe without special
respirator equipment, except perhaps in very deep valleys. Marginal planets
only; incompatible with "Cloud cover" or "Very dense atmosphere".

BIOLOGICAL FEATURES
Intelligent life: The planet has a native sentient life form, which may or
may not have advanced technology. Requires at least level III life;
incompatible with "Semi-intelligent life". Less likely with life below
level V (25% chance, otherwise roll again).
Semi-intelligent life: The planet has a native life form which is not fully
sentient yet, but comes close, and may develop further. Requires at least
level III life; incompatible with "Intelligent life". Less likely with life
below level V (25% chance, otherwise roll again).
World forest: The entire land surface (except ice caps, probably) is
covered by a single huge forest. Requires a non-zero land area, and at
least level II life.

ARCHAEOLOGICAL FEATURES
Ancient artifacts: Artifacts left behind by aliens, thousands or millions
of years ago, exist on the planet. The aliens may or may not have been
natives.

4.4. EXAMPLES
Sun
    G2, 9 planets: R5 H12 / E13.1 D7.2 / A G143.16 G121.18 G51.15 G51.8 C2.1
    3. Earth: Earthlike, diameter 13000 km, density 5.5 g/cm3, gravity 1.0
        G, rotation 24 h, orbit period 365 d (365 local days), temperature
        15 C, surface 25% L 70% W 5% I, minerals 80, 1 moon, advanced
        vertebrates, Earthlike biochemistry; intelligent life
Alpha Centauri
    A: G2, 6 planets: R9.3 H8 / H10 M15.2 / C5.1 G110.9
    A4: Marginal, diameter 15000 km, density 5.0 g/cm3, gravity 1.1 G,
        rotation 8 d, orbit period 324 d (40.5 local days), temperature -5
        C, surface 35% L 35% W 30% I, minerals 64, 2 moons, advanced
        invertebrates, protein-based biochemistry; eccentric orbit,
        volcanic activity
    B: K0, 2 planets: R10.2 / H8 /
    C: M5, 1 planet: H17.1 / /

5. COLONISATION
---------------
5.1. SECTOR CHARACTERISTICS
Two characteristics need to be determined for an entire sector. First,
decide how "civilised" the sector is -- that is, how much contact it has
had with interstellar society in general, and how much development has been
done. Second, choose the "opening date" for the sector -- the date at which
colonisation of the sector began.
Ideally, these should be decided before you start, rather than generated at
random. The following table is a suggestion for those who want one.
    D100    Sector description  Initial colonisation
    ------  ------------------  ----------------------
    1-30    Unexplored          D6x50 years ago
    31-60   Frontier            2D6x50 years ago
    61-90   Typical             (2D6x50)+250 years ago
    91-100  Developed           (2D6x50)+500 years ago

5.2. PLANET QUALITY
Habitable (Earthlike or marginal) planets can be rated according to their
desirability for human colonisation. Of course, aliens may have different
criteria; if your universe includes many alien colonies, you may have to
modify these rules.
Planet quality (PQ) ranges from 1 to 99 for habitable planets (a planet
rated 0 would be uninhabitable, and 100 is excluded on the reasonable
assumption that nothing is perfect). Start with a base value of 50, and
modify as described below. If the final result is less than 1, record it as
1; if it's more than 99, record it as 99.
    Planet details                          PQ modifier
    --------------------------------------  ----------------------
    Planet type
        Earthlike                           +35
        Marginal                            0
    Rotation period
        Up to 2 days                        0
        Greater than 2 days, up to 7 days   -5
        Greater than 7 days                 -10
    Surface gravity
        Up to 1 G                           0
        Over 1 G                            -5 per 0.1 G over 1
    Surface temperature
        Below 10 degrees                    -1 per degree below 10
        10 to 30 degrees                    0
        Over 30 degrees                     -1 per degree over 30
    Land area
        Zero                                -20
        5% to 10%                           -5
        15% to 85%                          0
        90% to 95%                          -5
        100%                                -10
    Mineral resources                       +MR/4
    Life development
        No life                             -20
        I: Single-celled organisms          -15
        II: Simple invertebrates/plants     -10
        III: Advanced invertebrates/plants  -5
        IV: Simple vertebrates              0
        V: Advanced vertebrates             0
    Biochemistry
        Earthlike                           0
        Protein-based                       -10
        Carbon-based                        -30
        Non-carbon-based                    -50
    Special features
        Astronomical features
            Eccentric orbit                 -10
            High inclination                -5
            High tides                      -5
            Meteor storms                   -20
            No seasons                      0
            Rings                           0
        Geological features
            Radiation hazard                -30
            Rugged terrain                  -5
            Volcanic activity               -20
        Hydrographic features
            Freshwater oceans               0
            Many islands                    0
            Poisonous oceans                -30
            Swampy surface                  -10
        Atmospheric features
            Cloud cover                     -10
            Toxic gas                       -30
            Unstable climate                -5
            Very dense atmosphere           -30
            Very thin atmosphere            -30
        Biological features
            Intelligent life [*1]           0
            Semi-intelligent life [*1]      0
            World forest                    0
        Archaeological features
            Ancient artifacts               +10
    [*1: Depending on what sort of interstellar society your universe has,
    you may decide that the presence of intelligent or semi-intelligent
    life would place a world off limits to colonisation.]
(For the statistically minded, to save you some calculations: Earthlike
planets average 74, with standard deviation 15; marginal planets average
24, s.d. 18.)

5.3. COLONIES
The basic chance that a planet will be colonised depends on the sector
civilisation level:
    Sector type  Colonisation chance
    -----------  ------------------------
    Unexplored   PQ / 2 percent
    Frontier     PQ percent
    Typical      PQ + 25 percent (max 99)
    Developed    PQ + 50 percent (max 99)
Roll the percentage or less on a D100. If the result is a success, find the
date of colonisation:
    Colonisation date = Sector opening date + (100 - PQ) x D100 / 10
If the planet failed the original colonisation roll, or the date is later
than the present date of your campaign, then the planet is uninhabited, and
you can stop here.
Find out how much contact the planet has had with interstellar civilisation
since its establishment. Again, the following is just a suggestion, and
should be adjusted to suit your universe's historical background. The same
contact level should probably be used for all inhabited planets in a
system.
    Sector type  Die roll
    -----------  --------
    Unexplored   D6-3
    Frontier     D6-1
    Typical      D10
    Developed    D6+4
    Result  Contact level       Population modifier
    ------  ------------------  -------------------
    0       No contact          -6
    1-3     Occasional contact  -2
    4-7     Regular contact     0
    8-10    Extensive contact   +2
Now determine the current population and technology level of the colony.
The population level is given by:
    Colony age     Basic population roll
    -------------  ---------------------
    0-99 years     2D6 + (PQ / 20)
    100-299 years  3D6 + (PQ / 20)
    300-499 years  4D6 + (PQ / 20)
    500-999 years  5D6 + (PQ / 20)
    1000+ years    6D6 + (PQ / 20)
Adjust for the contact level, and use the following table to generate the
actual population and tech level. See section 6 for a more detailed
explanation of the technology levels.
    Result  Population         Tech level roll
                               No contact  Any contact
    ------  -----------------  ----------  -----------
    0-4     D100               2D6         3D6
    5-7     D100x10            2D6         3D6
    8-10    D100x100           2D6         3D6
    11-13   D100 thousand      2D6         3D6
    14-16   D100x10 thousand   2D6         3D6
    17-19   D100x100 thousand  2D6+1       3D6+1
    20-22   D100 million       2D6+2       3D6+2
    23-25   D100x10 million    2D6+3       3D6+3
    26-31   D100x100 million   2D6+4       3D6+4
    32+     D100x1000 million  2D6+5       3D6+5
    TL roll  Tech level
    -------  --------------------------
    2        I: Stone age
    3        IIa: Bronze age
    4        IIb: Classical/mediaeval
    5        IIc: Renaissance
    6        IIIa: Steam age
    7        IIIb: Twentieth century
    8-9      IIIc: Cyberpunk
    10-12    IVa: STL interstellar
    13-16    IVb: FTL interstellar
    17+      IVc: Advanced interstellar

5.4. EXAMPLES
RGFM sector, in which these systems lie, has a typical civilisation level,
and was first colonised in the year 2500 AD; the present year is 3000 AD.
System RGFM-29
    A: K2, 7 planets: H9 R9 / M9.2 H11.2 / G150.11 G130.9 G170.19
    A3. Noviy Siberia: Marginal, diameter 11000 km, density 3.5 g/cm3,
        gravity 0.6 G, rotation 2 d, orbit period 213 d (107 local days),
        temperature 0 C, surface 50% L 25% W 25% I, minerals 57, 2 moons,
        advanced vertebrates, protein-based biochemistry; world forest;
        planet quality 44, colonised 2657 AD, occasional contact,
        population 7800, tech level IVa (STL interstellar)
    B: K5, 1 planet: R1.1 / /
System RGFM-158
    Star: F8, 14 planets: H10.2 R7.1 / R3.3 E14 / G140.11 G110.19 C8.1
        G120.3 G140.11 R5.4 G80.8 G140.13 G120.6 G80.6
    4. Tsarina: Earthlike, diameter 14000 km, density 3.5 g/cm3, gravity
        0.7 G, rotation 29 h, orbit period 534 d (442 local days),
        temperature 5 C, surface 20% L 55% W 25% I, minerals 51, no moons,
        advanced vertebrates, Earthlike biochemistry; high inclination,
        rings; planet quality 83, colonised 2611 AD, regular contact,
        population 72 million, tech level IVb (FTL interstellar)

6. TECHNOLOGY
-------------
This is a brief description of the tech level scale I've used. Some very
approximate equivalents are given for two well-known SFRPG tech level
scales, from SJG's _GURPS_ and GDW's _Traveller_.
Obviously any dates beyond the end of the twentieth century represent
little more than wild guesswork. Even if you use my technology scale, you
may want to change the dates and descriptions for the levels beyond
present-day technology. In particular, the point at which FTL travel is
developed will affect the history of your universe deeply.
Note that, in the interests of making this system usable with the vast
majority of SF universes, I haven't made any allowance for the possibility
that FTL travel really is impossible...
    "It can't be done!" they said to him
    And so he set to do it
    He tried to do what "couldn't be done"
    And he couldn't bloody do it.
        -- Anonymous
Group I -- Hunter-gatherer technology
    I: Stone age, before about 8000 BC [GURPS 0; Traveller 0]
        Stone tools, fire, language, spear, bow and arrow, boats
Group II -- Agricultural technology
    IIa: Bronze age, circa 8000 to 1000 BC [GURPS 1; Traveller 1 (early)]
        Copper, bronze, agriculture, wheels, swords, domestic animals,
        money, writing, sailboats, megalithic structures
    IIb: Classical/mediaeval, circa 1000 BC to 1400 AD [GURPS 2-3;
    Traveller 1 (late)]
        Iron, steel, glass, concrete, water wheel, catapult, crossbow,
        armour
    IIc: Renaissance, circa 1400 to 1700 AD [GURPS 4; Traveller 2]
        Gunpowder, printing, clockwork, telescope, large sailing ships,
        muskets, cannon
Group III -- Industrial technology
    IIIa: Steam age, circa 1700 to 1900 AD [GURPS 5; Traveller 3]
        Railways, steamships, telegraph, photography, rifles
    IIIb: Twentieth century, circa 1900 to 2000 AD [GURPS 6-7; Traveller
    4-7]
        Plastics, automobile, aircraft, tanks, radio, telephone, fission
        power, computers, guided missiles, satellites, nuclear weapons,
        automatic weapons
    IIIc: Cyberpunk, circa 2000 to 2100 AD ? [GURPS 8 (early); Traveller 8
    (early)]
        Fusion power, cyberspace, genetic engineering, nanotechnology,
        lasers
Group IV -- Interstellar technology
    IVa: STL interstellar, circa 2100 to 2200 AD ? [GURPS 8 (late);
    Traveller 8 (late)]
        Ramjet ships, terraforming, artificial intelligence
    IVb: FTL interstellar, circa 2200 to 3000 AD ? [GURPS 9-13; Traveller
    9-15]
        FTL travel, gravity control, mass conversion power
    IVc: Advanced interstellar, circa 3000 AD to ? [GURPS 14; Traveller
    16-21]
        Matter transmitter
Group V -- Kardashev type II civilisations
    V: Dysonian [GURPS 15; Traveller 22-27]
        Artificial worlds
Group VI -- Unknown technology
    VI: Unknown [GURPS 16+; Traveller 28+]
        Time travel

7. INTELLIGENT LIFE
-------------------
Obviously any system for designing intelligent aliens has to be based on at
least as much personal preference and just plain wild guesswork as hard
facts. Anyone who uses this system is urged to take a careful look at it
first and make any changes you think will bring it more in line with your
version of the universe.

7.1. PHYSICAL DESCRIPTION
This is intended to be a generic system for generating intelligent or
semi-intelligent species. Some minor modifications may be required to fit
some details of the aliens' home world, if you've already generated it;
most of these should be obvious enough that I don't need to spell them out
(for example, if the planet has no life more advanced than invertebrates,
you can exclude the vertebrates from the "metabolism and body structure"
roll).
Find the normal environment of the species:
    D100   Environment
    -----  --------------
    1-80   Land-dwelling
    81-82  Burrowing
    83-94  Amphibious
    95-99  Aquatic
    100    Flying
Find the type of metabolism and body structure:
    D100    Metabolism and body structure
    ------  -----------------------------
    1-15    Cold-blooded invertebrate
    16-20   Warm-blooded invertebrate
    21-30   Cold-blooded vertebrate
    31-100  Warm-blooded vertebrate
Find the type of body covering:
    D100    Types of body covering
    ------  ----------------------
    1-75    One main type
    76-100  Two main types
    D100                                              Body covering
    Flying  Invertebrate  Cold-blooded  Warm-blooded
                          vertebrate    vertebrate
    ------  ------------  ------------  ------------  -------------
    1-10    1-25          1-10          1-20          Soft-skinned
    15-20   26-50         11-30         21-30         Thick-skinned
    21-40   51-60         31-35         31-90         Furred
    31-80   61            36            91            Feathered
    81-89   62-70         37-80         92-97         Scaled
    90      71-75         81-83         98            Spiny
    91-100  76-100        84-100        99-100        Hard-shelled
Use the first column for all flying creatures; otherwise, use the column
appropriate to the creature's body type. If there are two types of body
covering, re-roll the second if it comes out the same as the first.
Find the type of body symmetry and the number of limbs:
    D100                      Symmetry   Number of limbs
    Invertebrate  Vertebrate
    ------------  ----------  ---------  ---------------
    1-20          1-60        Bilateral  4
    21-40         61-90       ...        6
    41-60         91-95       ...        8
    61-80         96-97       ...        (D6+4)x2
    81-85         98          ...        (D100+10)x2
    86-95         99          Radial     5
    96-100        100         ...        D10+2
(If you're wondering why most of the creatures with radial symmetry have
five limbs, it's not just Earth prejudice; there are good engineering
reasons why five is the optimum number of limbs for a creature with radial
symmetry. Having an even number of body segments is a bad idea, because it
weakens the body by placing several continuous seams around it. A creature
with three arms would probably be unable to survive if it lost one; five
are much better for redundancy. There are some echinoderms on Earth with
more than five limbs, but not many.)
For creatures with radial symmetry, all limbs are assumed to be dual
purpose arm/legs. Flying creatures with radial symmetry are assumed to be
lighter-than-air, balloon-like creatures.
For creatures with bilateral symmetry, roll once for each pair of limbs,
except as noted below:
    D100    Type of limbs
    ------  --------------------------------------------------------------
    1-10    Wings if flying; fins if amphibious or aquatic; otherwise legs
    11-50   Fins if aquatic (not amphibious); otherwise legs
    51-70   Legs
    71-75   Dual-purpose arm/legs
    76-100  Arms
For flying creatures, assign one pair of limbs as wings without rolling
(wings generated on the table are additional pairs). All intelligent
creatures will have at least one pair of hands (either arms or arm/legs).
If you get a result that violates any of these checks, start again. If the
creature has more than ten limbs, roll only for the first five pairs; the
rest are all assumed to be legs.
Find the creature's diet:
    D100    Diet
    ------  -----------
    1-10    Herbivorous
    20-70   Omnivorous
    80-100  Carnivorous
Find the creature's method of reproduction:
    D100   Type of reproduction
    -----  --------------------
    1-5    Asexual
    6-25   Hermaphroditic
    25-99  Two sexes
    100    Three sexes
    D100                                      Method of reproduction
    Invertebrate  Cold-blooded  Warm-blooded
                  vertebrate    vertebrate
    ------------  ------------  ------------  ----------------------
    1-5           --            --            External budding
    6-80          1-70          1-30          Egg-laying
    81-100        71-100        31-100        Live-bearing
Find the average mass and size of the creature; roll 2D10 for land-dwelling
or amphibious creatures, 2D10+3 for aquatic creatures, or 2D6 for flying or
burrowing creatures:
    Result  Mass    Size
    ------  ------  ---------------
    2       2 kg    (2D6+5) x 4 cm
    3       5 kg    (2D6+5) x 6 cm
    4       10 kg   (2D6+5) x 8 cm
    5       15 kg   (2D6+5) x 9 cm
    6       20 kg   (2D6+5) x 10 cm
    7       30 kg   (2D6+5) x 11 cm
    8       40 kg   (2D6+5) x 12 cm
    9       50 kg   (2D6+5) x 13 cm
    10      60 kg   (2D6+5) x 14 cm
    11      75 kg   (2D6+5) x 15 cm
    12      100 kg  (2D6+5) x 16 cm
    13      150 kg  (2D6+5) x 18 cm
    14      200 kg  (2D6+5) x 21 cm
    15      300 kg  (2D6+5) x 24 cm
    16      500 kg  (2D6+5) x 28 cm
    17      1 t     (2D6+5) x 35 cm
    18      2 t     (2D6+5) x 45 cm
    19      5 t     (2D6+5) x 60 cm
    20      10 t    (2D6+5) x 75 cm
    21      20 t    (2D6+5) x 1 m
    22      50 t    (2D6+5) x 1.3 m
    23      100 t   (2D6+5) x 1.6 m
For flying creatures and snake-like creatures (any non-aquatic creatures
without legs), multiply the size by 4. The size generated is the creature's
greatest dimension -- height for humanoids, length for most horizontally
oriented creatures, wingspan for flying creatures. Round the size to the
nearest 10 centimetres (or 5 centimetres if it's less than one metre).

7.2. SPECIAL FEATURES
This section covers the sort of features that many role-playing games treat
as advantages and disadvantages -- natural weapons, unusually fast or slow
speed, non-human senses, and so forth. Some features relevant to your game
mechanics will have already been generated, such as the ability to fly or
swim, extra hands, or whatever degree of natural armour is implied by the
creature's body covering.
Attributes such as strength, dexterity, intelligence and so on are too
game-specific to be covered here. You'll have to wing it.
Roll D6-3 to determine how many special features the species has. Then roll
D100 on the following table the appropriate number of times; re-roll any
repeated results. Some of the entries are double (e.g. "acute vision/poor
vision"); the two are mutually exclusive, and there is a fifty-fifty chance
of one or the other. The "acute" or "poor" senses are relative to human
senses (which is why there's no "poor smell" feature -- the human sense of
smell is pretty poor to start with).
I haven't included precise definitions of the effects of each of these
special features; any details beyond what is implied by the names would
have to be worked out to fit your particular game mechanics.
    D100                            Special abilities
    Herbivore  Omnivore  Carnivore
    ---------  --------  ---------  ------------------------------------
    1-18       1-17      1-16       Acute hearing/poor hearing
    19-30      18-28     17-26      Acute smell
    31-48      29-45     27-42      Acute vision/poor vision
    49-60      46-56     43-52      Ambidextrous
    61-62      57-58     53-54      Chameleon skin
    63-68      59-64     55-59      Cold sensitivity/cold tolerance [*1]
    69-74      65-70     60-64      Colour blind
    75-80      71-76     65-69      Heat sensitivity/heat tolerance [*1]
    81-86      77-82     70-74      Infrared vision
    87-91      83-88     75-84      Night vision
    92         89-91     85-89      Poison
    93         92        90         Radiation tolerance
    94         93        91         Radio communication
    95         94        92         Radio sense
    96         95        93         Ranged weapon
    97         96        94         Regeneration
    98         97-98     95-97      Sonar [*2]
    99         99        98         Suckers (wall climbing)
    100        100       99         Vacuum tolerance
    --         --        100        Web spinning
    [*1: If you're creating an intelligent species for an already-generated
    planet, the planet's surface temperature will affect the natives'
    heat/cold tolerance. If the temperature -5 degrees or less, the natives
    automatically have cold tolerance, and have a 50% chance of heat
    sensitivity; ignore and re-roll any of the [*1] results. If the
    temperature is 35 degrees or higher, the natives automatically have
    heat tolerance, and have a 50% chance of cold sensitivity; ignore and
    re-roll any of the [*1] results. If the temperature is 0 to 30 degrees,
    generate as above.]
    [*2: Sonar implies acute hearing; add acute hearing to your list of
    features (don't count it towards the total), and ignore any other rolls
    of acute/poor hearing.]
Two other special features are determined separately: natural weapons and
speed.
The chance that the aliens will have natural weapons (claws, fangs, horns,
or whatever) is 20% for herbivores, 40% for omnivores, and 80% for
carnivores. This refers only to close-combat weapons; ranged weapons are
generated separately from the table above.
Roll 2D6 on the following table to find the aliens' running (or swimming or
flying) speed, relative to human speed. Add 1 for carnivores. For land or
water creatures, subtract 2 if their average body mass is less than 10
kilograms. For flying creatures, don't adjust for mass, and double the
speed (the final multiplier, not the die roll).
    Result  Speed
    ------  -----
    0-3     x1/2
    4-9     x1
    10-11   x2
    12      x3
    13      x4

7.3. PSYCHOLOGICAL PROFILE
The psychological profile of an intelligent species is described by a set
of six numbers: social, cooperation, aggression, exploration, technology,
and art. Each runs from 0 to 100.
Social: Indicates the degree of gregariousness and social organisation in
their civilisation. A social rating of zero would indicate a totally
solitary species with no social interaction at all; a social rating of 100
would indicate a hive-mind species with no concept of individual identity.
Some social contact is assumed to be required for the evolution of language
and intelligence, so a social rating less than 5 is not allowed in this
system.
Cooperation: Indicates how willing they are to cooperate with other
intelligent species. A cooperation rating of zero would indicate a totally
xenophobic species that refuses to even recognise the existence of any
other intelligent life; a cooperation rating of 100 would indicate a race
with no sense of species identity at all, making no distinction between
their own conspecifics and aliens.
Aggression: Indicates how warlike they are, both among themselves and
against other species. An aggression rating of zero would indicate a
completely pacifist species that never fought anyone for any reason; an
aggression rating of 100 would indicate a completely warlike species with
no interest in any other activity. For obvious reasons there will be a
negative correlation between the cooperation and aggression ratings (but
not completely -- for example, a species that enjoyed fighting and
frequently hired themselves out as mercenaries to anyone who needed
soldiers might have a high rating in both areas, while a peaceful but
isolationist species, such as Larry Niven's Puppeteers, would have a low
rating in both).
Exploration: Indicates their curiosity and interest in research and
exploring the universe. An exploration rating of zero would indicate a
species with no curiosity at all (since this seems incompatible with
intelligence, a rating of less than 5 is not allowed); an exploration
rating of 100 would indicate a species completely obsessed with exploration
or science.
Technology: Indicates their technological aptitude. A technology rating of
zero would indicate a species with no technology of any kind; a technology
rating of 100 would indicate a species obsessed with technology to the
exclusion of anything else. There is a strong positive correlation between
the exploration and technology ratings.
Art: Indicates what part artistic activities play in their society. An art
rating of zero would indicate a completely practical and utilitarian
species, with no aesthetic sense at all (to humans they would seem cold and
robotic); an art rating of 100 would indicate that aesthetic considerations
completely dominated practical ones (this would not be a survival trait,
which is why an art rating above 95 is not allowed). There is a negative
correlation between the technology and art ratings.
    Profile      Basic                            Modifiers      Allowed
    element      die roll                                        range
    -----------  -------------------------------  -------------  -------
    Social       (2D6x10)+D10-25                  Herbivore +10  5-100
                                                  Omnivore  0
                                                  Carnivore -10
    Cooperation  (2D6x10)+D10-25                  Herbivore 0    0-100
                                                  Omnivore  +5
                                                  Carnivore -5
    Aggression   (2D6x10)+D10-(Cooperation/5)-15  Herbivore -10  0-100
                                                  Omnivore  0
                                                  Carnivore +10
    Exploration  (2D6x10)+D10-25                  Herbivore -10  5-100
                                                  Omnivore  +5
                                                  Carnivore +5
    Technology   (D6x10)+D10+(Exploration/2)-15   --             0-100
    Art          (2D6x10)+D10-(Technology/5)-15   --             0-95
If the result is outside the allowed range, roll again.

7.4. TECHNOLOGY
To find a race's typical technology level, roll 2D10, add one-fifth of
their technological aptitude (from the psychological profile), and refer to
the following table:
    TL roll  Tech level
    -------  --------------------------
    0-6      No technology
    7-13     I: Stone age
    14       IIa: Bronze age
    15       IIb: Classical/mediaeval
    16       IIc: Renaissance
    17       IIIa: Steam age
    18       IIIb: Twentieth century
    19       IIIc: Cyberpunk
    20       IVa: STL interstellar
    21-25    IVb: FTL interstellar
    26-34    IVc: Advanced interstellar
    35-38    V: Dysonian
    39+      VI: Unknown

7.5. EXAMPLES
Descriptions of the human race and two alien races:
Human -- Land-dwelling, warm-blooded vertebrate, soft-skinned, bilateral
    symmetry, 4 limbs (2 arms, 2 legs), omnivorous, two sexes,
    live-bearing, mass 75 kg, size 1.8 m, speed x1; Soc 65, Coop 55, Aggr
    65, Expl 75, Tech 65, Art 45; tech level IIIb (twentieth century)
Alien 1 -- Land-dwelling, warm-blooded vertebrate, furred, bilateral
    symmetry, 6 limbs (2 arms, 4 legs), carnivorous, hermaphroditic,
    live-bearing, mass 20 kg, size 1.4 m, speed x2; natural weapons; Soc
    63, Coop 54, Aggr 17, Expl 31, Tech 52, Art 72; tech level IVb (FTL
    interstellar)
Alien 2 -- Amphibious, cold-blooded vertebrate, scaled, bilateral symmetry,
    4 limbs (2 arm/legs, 2 legs), herbivorous, two sexes, egg-laying, mass
    200 kg, size 2.9 m, speed x1; acute hearing, heat sensitivity; Soc 52,
    Coop 73, Aggr 67, Expl 51, Tech 75, Art 50; tech level IVc (advanced
    interstellar)
---------------------------------------------------------------------------

--
Ross Smith ........................................ Wellington, New Zealand
Home: ................. Work:
          "Those who do not remember the past are condemned to
          watch the mini-series."             -- Diana Wichtel
 

Voilà, comme évoqué dans un autre sujet, je vous colle brut de fonderie une aide de jeu que j'avais trouvé il y a une vingtaine d'années, et que j'ai trouvé tout simplement géniale. Je laisse le nom de l'auteur, car ce n'est pas mon travail, bien entendu.
 
Je pense qu'elle serait très utile pour Chroniques Galactiques.
Par contre, c'est en Anglais, c'est assez aride (à l'époque sur Internet on ne s'embarassait pas trop de la mise en forme), et c'est basé sur les connaissance scientifiques de l'époque (en 1995 la première exoplanète venait d'être découverte, et on considérait encore Pluton comme une planète !)
 
MRick

Merci beaucoup MRick ! C'est vrai que la présentation est un peu aride mais le fond est intéressant.

Oui merci çà a l'air intéressant en effet (si qq'un ayant un peu de temps devant lui pouvait nous faire un coup de mise en page en prime histoire que ce soit un peu plus agréable à décortiquer, ce serait encore mieux  

Oui merci çà a l'air intéressant en effet (si qq'un ayant un peu de temps devant lui pouvait nous faire un coup de mise en page en prime histoire que ce soit un peu plus agréable à décortiquer, ce serait encore mieux
SRG408

Je maîtrise actuellement une campagne Pathfinder, mais j'approche de la fin.

Je vais sûrement faire autre chose après, peut-être du Chroniques Galactiques, si c'est le cas, je prendrais probablement le temps de faire une vraie mise en page pour ce truc.

Mais bon j'ai dit la même chose pour un autre projet (Midnight Chronicles), bien évidemment, tout ceci dépendra aussi de mes joueurs, de ce qu'ils ont envie de jouer après quand la campagne Pathfinder sera terminée.

Mais bon j'ai dit la même chose pour un autre projet (Midnight Chronicles), bien évidemment, tout ceci dépendra aussi de mes joueurs, de ce qu'ils ont envie de jouer après quand la campagne Pathfinder sera terminée.

MRick

"Ce que joueur veut, Dieu le veut"

Adaptation libre et "plus simple" du système de base. y a même 20 "pistes" de scénario...

(par contre, il doit rester des phôtes aussi... Pardon d'avance)

Type et nombre d'étoile :

-1D6-2 (minimum 1) pour connaître le nombre d'étoiles présentes dans le système.

-1D8 pour le type d'étoile :

1 = O/B bleue ou bleue-blanche

2 = A blanche

3 = F/G jaune ou jaune-blanche

4 = K orange

5 = M rouge

6 = gM géante-rouge

7 = DA naine-blanche

8 = Objet atypique (1D6/2 sur la table en dessous)

-1D6/2 pour les objets atypiques :

1 = Super-géante (et relancer le D8 pour déterminer le type. Si il retombe sur un 8, choisir entre un super trous-noir ou une étoile à neutron en effondrement aka une supernova)

2 = Trou-noir

3 = Étoile à neutrons

Système planétaire :

Les étoiles de type O-B-A-M possèdent 1D10 planète(s)

Les étoiles de type F-G-K possèdent 2D6 planète(s)

Les étoiles géantes et super-géantes ainsi que les naines-blanches, les étoiles à neutrons ainsi que les trous-noirs possèdent 1D6-3 planète(s) (pas de minimum)

Il suffit ensuite de répartir les planètes entre les zones A (proche de l'étoile), B (à distance idéale) et C (éloigné de l'étoile) selon leurs types. Les zones A et B ne peuvent accueillir chacune qu'un quart du nombre total de planètes. La zone C peut en contenir la moitié.

il est possible de définir librement chaque planète ou de se référer à la table suivante en lançant 1D10 :

1 = Astéroïdes (proto-panète), 0 lunes, toutes zones

2 = Géante gazeuse (Jupiter), 1D6+2 lunes, toutes zones

3-5 = Rocheuse (Mercure), 0 lunes,toutes zones

6 = Froide (Pluto), 1D4 lunes, zone C

7 = Déserte (Mars), 1D4/2 lunes, toute zones

8 = Hostile (Venus), 1D4 lunes, zones A et C

9 = Marginale (Proto-Terre dure à vivre, pas d'exemple dans le système solaire), 1D6/2 lunes, zones A, B et C

10 = Terra (Terre), 1D4/2 lunes, zone B

Chaque système possède une chance sur vingt d'abriter de la vie, +1 par planètes. Pour définir le niveau de développement de la vie, on lance 1D10 :

1-2 = Organisme mono-cellulaire

3-4 = Invertébrés/plantes basiques

5-6 = Vie animale et végétale

7-8 = Espèce consciente et civilisé (proto-histoire)

9 = Civilisation technologique (Humanité actuelle)

10 = Civilisation spatiale (pré-singularité)

Chaque système peut être relié à plusieurs autres via des singularités. Lancez 1D6 :

1-4 = le système est relié à deux autres systèmes

5 = le système est relié à trois autres systèmes

6 = le système est relié à 1D6 autres systèmes

Éléments particuliers :

Pour rajouter du piment et de la surprise, vous pouvez lancer 1D20 par système (Attention à ne pas le faire à chaque fois, sinon cela retirera une partie du plaisir de la découverte) :

1 = L'une des planètes possède des artefacts d'une civilisation disparue

2 = L'une des planètes tourne à contre-sens

3 = L'une des planètes présente toujours la même face à son étoile

4 = Le système abrite une structure spatiale extra-terrestre de petite taille

5 = Le système abrite une structure spatiale extra-terrestre de grande taille

6 = Le système abrite une ou plusieurs planètes qui ont étaient terra-formées

7 = Si la Vie est présente, elle est extrêmement diversifiée et prolifique

8 = Si la vie est présente, elle est une conscience unique

9 = Si la vie est présente, elle ressemble fortement à l'Humanité

10 = L'une des lunes du système abrite énormément de ressources

11 = L'une des lunes du système à des propriétés physiques surprenantes

12 = L'une des lunes du système n'est pas d'origine (et provient d'un autre système)

13 = Une espèce originaire d'un autre système est présente en exploration

14 = Une espèce originaire d'un autre système est présente sur des colonies

15 = Une espèce originaire d'un autre système est présente et à colonisée la plupart des planètes

16 = Toutes les planètes ont étaient vidées de leurs ressources.

17 = Toutes les planètes ont étaient bougées de leurs orbites d'origines

18 = Toutes les planètes sont vitrifiés suite à un conflit nucléaire dans le système.

19 = l'étoile du système est incroyablement jeune, pour son age...

20 = L'étoile du système est en fin de vie.

Adaptation libre et "plus simple" du système de base. y a même 20 "pistes" de scénario...

Den

Merci Den pour cet excellent travail, cela me paraît bien plus clair ainsi !

Merci Den pour cet excellent travail, cela me paraît bien plus clair ainsi !

Dox

De rien : En revanche, ce que je propose est beaucoup moins accurate niveau scientifique que la version d'origine (le taux d'étoiles de type M par exemple est totalement foireux chez moi) c'est pas trop grave mais je tiens à le signaler (sinon je ais m'en vouloir jusqu'à la fin des temps).

Je le conseil pour des choses à la volée (pour cause de PJ trop curieux) mais si vous avez le temps, ça ne doit servir que de vague base, quitte à y faire les jets et modifier le résultat pour s'approcher ensuite de ce qui correspond le plus à votre vision.

Je n'ai pas non plus pris la peine de faire des systèmes extra-terrestres post-singularité en détail, l'aide de jeu servant surtout à explorer des régions isolées ou encore inconnues de la plupart des Races avancées.

En gros, prenez ce qui vous plaît et faites en ce que vous voulez ^^

AMHA, un système de génération de systèmes planétaires et de mondes pour un jeu de space op ne doit surtout pas être exact du point de vue statistique / scientifique, sans quoi au cinquième scénario se déroulant dans un système où une naine rouge éclaire difficilement trois cailloux gelés, les joueurs vont vouloir passer à autre chose

J'avoue que la diversité, c'est la vie.
Mais un minimum de cohérence, je ne suis pas contre non plus (tout est une question de dosage en fait).
Après, l'univers contient suffisament "d'abération" au bon sens pour que beaucoup de chose soient possibles !

Je pense faire un petit tableau récapitulatif de ce genre de phénomènes totalement improbables !

Pour mon univers de jeu de space opéra, j'ais recensé toutes les étoiles proches (à moins de 50 années lumière de la Terre) connues à ce jours... et bien, je les ais mis sur une carte à plat (oui, je ne sais pas faire de la 3D avec une feuille de papier ). il y a pas mal d'étoiles de type rouge, surtout très proche de la Terre et en plus, récemment j'ai appris qu'il y avait entre 1000 et 2000 étoiles supplémentaires non répertoriées possible dans cette sphère de 50 AL O.o

Pour mon univers de jeu de space opéra, j'ais recensé toutes les étoiles proches (à moins de 50 années lumière de la Terre) connues à ce jours... et bien, je les ais mis sur une carte à plat (oui, je ne sais pas faire de la 3D avec une feuille de papier ). il y a pas mal d'étoiles de type rouge, surtout très proche de la Terre et en plus, récemment j'ai appris qu'il y avait entre 1000 et 2000 étoiles supplémentaires non répertoriées possible dans cette sphère de 50 AL O.o

Ashram Draconian

J'avais fait un peu la même chose avec mon almanach d'astronomie il y a 20 ans quand je maîtrisais un jeu space op' !

Enfin je ne crois pas que j'étais allé jusqu'à 50 AL, seulement 25 ou 30 je crois...

Et pareil, j'avais fait une carte à plat. Ce qui n'est pas si délirant que ça, puisque globalement la majorité des étoiles de la Voie lactée (notre Galaxie) sont presque sur un même plan (quand on regarde la voie Lactée par la tranche, elle n'est pas si épaisse que ça !).

La quasi-totalité des planètes est sur le même plan galactique. Certes les distances réelles donnent le vertige (et donc celles en "hauteur" aussi), mais je pense que pour le plaisir du jeu, on est en droit de les passer sous la case "facilité".

Hormis bien sur si c'est une partie en mode "ultra réaliste", mais c'est encore autre chose.

Ultra réaliste, en général, ce n'est pas intéressant à jouer...

Déjà, rien que la vitesse de la lumière, si on ne peut pas la dépasser pour les voyages, c'est juste monstrueux les temps de voyages pour aller d'un système à l'autre...

D'un autre côté, ça peut être intéressant un setting où l'on ne peut pas se déplacer plus vite que la lumière, et que chaque expédition vers un système voisin est un événement en soit qui se prépare sur plusieurs années et qui implique d'envoyer des gros vaisseaux autonomes auto-suffisant pour plusieurs années de voyage.

Mais après, il faudrait que les colons puissent construire des genre de portails permettant de passer d'un endroit colonisé à un autre plus rapidement...

Mais après, il faudrait que les colons puissent construire des genre de portails permettant de passer d'un endroit colonisé à un autre plus rapidement...

MRick

Ou bien il faudrait que les colons sont envoyés en cryogénie pendant le voyage.

Il y aurait là de quoi faire une excellente campagne de Space Opera !

Et il existe dans l'espace des portails fixes ou dérivants permettant de se déplacer beaucoup plus loin selon le principe des trous de vers.

Ces Portails ou Portes des Etoiles seraient des passages privilégiés pour voyager d'une galaxie lointaine à une autre... encore faut-il pouvoir les activer

Voyager vers une galaxie lointaine ?!?

Déjà, si on est limité à la vitesse de la lumière, il faut plus de 100 000 ans pour traverser la Voie lactée !

Alors les trous de vers, sont indispensable pour voyager à l'intérieur de notre bonne vieille Galaxie, quand à explorer d'autres Galaxies, alors là, je crois que c'est juste carrément hors de portée...