The hydrosphere of a planet is how much of its surface is covered by water. This is influenced by several factors. Since a planet’s oceans are formed of water released by volcanic activity, big planets (which are more active) tend to have more water
than small ones.
Climate also plays a big role. Worlds which are Hot have only half as much ocean because a large amount of water is in vapor form. Very Hot or Extremely Hot worlds have no oceans at all.
Very Cold or Extremely Cold worlds have no oceans of water, but might have seas of ammonia or liquid methane. If those chemicals exist and the planet has a Dense atmosphere, the GM may roll for the coverage of other liquids. Otherwise they have a Hydrographic percentage of zero.
Finally, there is a random element depending on how rough the surface is. A planet with deep ocean basins could have a lot of water but still have plenty of dry land; a smooth planet with little relief might be completely covered by a shallow ocean.
To compute hydrosphere randomly, roll 2d6 and multiply by 10 percent. (Apply the modifiers in the accompanying table.) Add or subtract 1d6 percent for some variability, if you want. The result is the amount of surface covered by ocean. If the result is 10 exactly, then the planet has large islands;
an 11 indicates a few small islands; and 12 means a true “waterworld” with absolutely no land at all.
DOMINANT TERRAIN
The terrain of a planet varies widely, of course
— just think of all the different landscapes on Earth. The most important factors in figuring landscapes are hydrosphere, climate, and tectonic activity (a function of mass). Hydrosphere indicates how much of the surface is desert, climate tells how much tundra or icecap there is, and mass gives an idea of how mountainous the world is. But because so much depends on random accidents of the planet’s history, there is no convenient formula. The GM simply has to decide on his own.
Earth’s land surface has approximately 25 per-cent desert, 10 perper-cent ice cap, 10 perper-cent tundra, and 5 percent mountainous terrain. The rest is a mix of tropical forest, temperate forest, grassland, and wetland.
Since Earth is 70 percent ocean and still has deserts, any world with less water is likely to have
SURFACE
PLANET CLASSIFICATIONS
At present, scientists only have the planets of the Solar System and a few bodies detected around other stars to study. They have only been able to recognize some very general types — gas giants, solid planets, and icy bodies like Pluto. An interstellar society with data on hundreds of star systems and thousands of planets might come up with a set of standard “planet classes” as a short-hand for scientists and explorers. For example, in the Star Trek series, planets get a letter classifica-tion — habitable Earth-like worlds are “Class M,”
gas giants like Jupiter are Class J, and so forth.
The exact criteria for a planetary classification scheme depend on who is doing the classifying, and why. Space travelers and merchants might simply group them into “inhabited” and “unin-habited,” while planetologists could have a highly detailed system based on internal structure and chemical composition.
The Terran Empire, in the Hero Universe timeline, uses a system of loose types geared mostly toward determining a planet’s suitability for colonization or economic exploitation. The types are denoted by numbers, on a scale which indicates the planet’s usefulness:
Type Description
1 Earthlike planets with compatible native life
2 Lifebearing worlds requiring life sup-port for Humans
3 Planets suitable for terraforming (Mars)
4 Icy dense-atmosphere worlds (Titan) 5 Airless rocky worlds (Moon, Mercury) 6 Airless icy worlds (Pluto, Europa) 7 Asteroids (Phobos, Ceres) 8 Greenhouse planets (Venus) 9 Small gas giant planets (Uranus,
Neptune)
10 Large gas giant planets (Jupiter, Saturn)
HYDROSPHERE MODIFIERS
and determine year lengthStep 2: Determine mass by rolling on the Plan-etary Mass Table.
Step 3: Determine com-position on the Plane-tary Composition Table, then compute density based on composition.
Step 4: Compute diam-eter, equal to the cube root of (mass divided by density) in Earth diam-eters. Multiply by 12,800 to get kilometers.
Step 5: Determine grav-ity by multiplying den-sity by relative diameter.
Step 6: Roll on the Moons Table to deter-mine how many moons the planet has; figure orbital distance by roll-ing the the Moon Dis-tance Table; determine size by rolling on the Moon Size Table; check the Moon Anomalies Table.
Step 7: Roll on the Plan-etary Rotation Table to determine day length;
check the Rotation Anomalies Table; roll for axial tilt on the Axial Tilt Table.
Step 8: Determine atmosphere composi-tion by rolling on the Atmospheric Composi-tion Table.
Continued on next page
very extensive deserts. A good rule of thumb is that the non-desert portions make up a per-centage of the planet’s land area roughly equal to the percentage of the planet as a whole that is covered by land. So a world with 50 percent ocean area would have land that is 50 percent desert, and a planet with 30 percent ocean would have desert covering 70 percent of its land surface.
Icecaps depend on climate and hydrography. The ice surface varies between 0 percent (on Warm worlds) and 100 percent (on Very Cold planets). For every 2 degree of temperature below 50 degrees Centigrade, increase the ice cap and tundra coverage by 1 percent each. Ice caps can never cover more of the surface than the oceans.
Mountains depend on how active the planet’s crust is. Small planets like Mars have few moun-tains (but those it does have are really big because they stay in one place and keep growing). Multiply the planet’s mass by 5 percent to get the amount of the surface cov-ered by mountains. Obviously, the
result cannot be greater than the total land surface.
The other terrain types depend heavily on the local life forms and the way the continents are.
One can assume that drier worlds are likely to have more grassland, wetter ones to have more wetlands, hotter ones to have more tropical forest, and cooler ones to have more temperate forest. But a cold planet might have all its continents in the relatively warm equatorial regions, and so have a high pro-portion of tropical landforms.
RESOURCES
There are ten types of resources found on planets:
Of course, this is a highly simplified list. The first five are found on nearly every world, though quanti-ties may vary and it may be easier to extract certain minerals on certain planets. Animals and plants are found on just about any lifebearing world, but certain species with valuable properties may exist in only a
single environment on one planet. The products of intelligent species obviously come only from planets that have inhabitants capable of making them.
Gamemasters creating a world randomly can roll for each resource type using 1d6. On a roll of 1, the planet is poor in that material, on a 6 it is rich.
The description of each category, below, includes modifiers based on the planet conditions. Worlds rich in a given resource are likely to be exporters, while worlds poor in something must import it or do without. Planets in the middle range have enough to supply local demand. Gamemasters building a world should only bother listing the rich and poor resources on the template unless more detail is desired or necessary.
HEAVY METALS
Heavy metals are radioactive substances like uranium and thorium, or precious metals like gold and silver. They have many applications — at lower technology levels they are valued as money, and at higher ones they become useful as sources of nuclear power, or in construction of electronic devices. Heavy metals, like other metals, are most common on rock-iron planets, and can be found on rock and rock-ice worlds as well. The more dense a planet is, the more likely it is to have heavy metals in quantity. Rock-iron planets get a +1, rock-ice planets get a -1, and ice planets get a -4. The roll gets an additional +1 if the planet’s density is greater than 1.
METALS
Metals are substances like iron, aluminum, copper, and titanium. They are most often used for
Continued from last page Step 9: Determine atmosphere density by rolling on the Atmo-spheric Density Table, then calculate pressure by multiplying atmo-sphere density by sur-face gravity.
Step 10: Determine climate, either by calcu-lating temperature based on distance or by using the base temperature for the planet’s orbital zone.
Modify for albedo, tidal heating, and greenhouse effect.
Step 11: Determine if the planet has any native life. If so, modify the atmosphere accordingly, then refigure climate.
Step 12: Roll on the Life Complexity Table to see what kind of creatures exist.
Step 13: Roll to see if any intelligent life exists (a 2d6 result of 12, or a 24 on 4d6 for hard sci-ence); check to see if the planet has any colonies on it.
Step 14: Determine ocean coverage by roll-ing 2d6 times 10 per-cent, with modifiers for mass and climate.
Step 15: Determine the dominant terrain based on climate, hydrography, and mass.
Step 16: Roll 1d6 for each resource category;
on a 6 the world is rich in those resources, on a 1 it is poor (use modifi-ers based on other plan-etary characteristics).
structural purposes, particularly in civilizations with industrial-era or higher technology. Metals are common on rock-iron worlds, available on rock worlds and rock-ice worlds, and rare on ice worlds. More massive planets tend to have more metals. The die roll is +1 for rock-iron planets, unmodified for rock and rock-ice, and -4 on ice planets. There is a +1 modifier for planets with a mass greater than 1 Earth.
NONMETALS
Nonmetals are solid substances like sulfur, silica, crystals, potassium nitrate, and the like.
They have a variety of uses, both as materials for ceramics and as feedstocks for chemical indus-tries. Crystals are nonmetals, and in fiction often have remarkable properties. Nonmetals are most common on rock worlds, and are available on all others except gas and hydrogen planets. Rock worlds get a +1 for nonmetals, others are unmodi-fied.
VOLATILES
Volatiles are liquids and gases, especially water, ammonia, hydrogen, helium, and the like.
They are hard to find on Yellow zone planets, but are available in the Green zone and are common in the Blue and Black zones. Rock-ice and ice planets have good supplies of volatiles. Volatiles have three main uses: as fuel for rocket-powered spacecraft;
as the raw materials for life support for ships and space stations; and as the basis for a great many chemicals. Planets in the Yellow zone get a -4 modifier on the roll for volatiles, worlds in the Blue and Black zones get a +1. Ice and rock-ice planets get a +3 modifier.
ORGANICS
Organics are chemicals made from the amaz-ingly versatile element carbon. They range from simple substances like methane and cyanide to complex lipids, alcohols, and petrochemicals.
Organics are very rare on Yellow zone worlds as the high temperatures break them down. On Green zone worlds with life, organics are found in the biomass. In the Blue and Black zones primor-dial organics can be found, especially on worlds with abundant methane. Organics are an impor-tant energy source at industrial-era technology, and are also vital for making plastics, pharmaceu-ticals, or chemicals. Yellow zone worlds get a -4 on the roll for organics, rock-ice and ice planets get a +1, and any world with life that is water-based, ammonia-based, or methane-based get a +3.
PLANTS
Plants and plant products are only available on planets where plant life has evolved. Plants in general are common on such worlds, but particular species with special properties can be exceedingly rare. They are most commonly used for food, but plant extracts can also be a source of pharmaceuti-cals or spices. Trees and similar big plants provide materials for building, and other plants supply fibers for cloth. When rolling for the resource, one can assume that there are plants growing all over
any world with life in the Yellow, Green, or Blue zones; the die roll indicates how useful or valuable the world’s plants are.
ANIMALS
As with plants, animals exist only on lifebear-ing worlds. Not all lifebearlifebear-ing planets have animal life — the GM should decide if a given planet does.
Animals are used for food by many races, and their skins are a traditional material for clothing. Some animal species produce toxins or other substances which can have importance as medicines. The roll for animal resources requires that the planet have native multicellular life, but is otherwise unmodi-fied.
CRAFTS
Crafts are the products of preindustrial cul-tures, chiefly from societies at Stone Age through preindustrial technology. Pottery, cloth, woodwork, and items made of bone and leather are typical crafts. Their value in interstellar trade derives mostly from aesthetic value, and they are treated as artworks. When rolling randomly, treat a die result of 1-5 as neutral — the planet’s people make crafts for their own use but don’t export anything.
A result of 6 means the culture’s crafts are interest-ing or beautiful enough to have value elsewhere.
The roll for crafts has no modifiers, but obviously the planet must have intelligent inhabitants with manipulatory limbs to make them. (For an exam-ple of an intelligent species without manipulatory limbs, and the problems this causes, see Arthur C.
Clarke’s short story “Second Dawn.”) MANUFACTURES
Manufactures are those products made in factories at industrial or later technology. Manu-factured goods are seldom as lovingly made or beautiful as handcrafts, but they are vastly cheaper and available in enormous quantities. This means factories are built only when there is a sufficiently large market for their wares. Many planets import manufactured goods, either because the local tech-nology cannot produce them or because the local population is too small to support a factory. The range of manufactured goods is vast — from plas-tic trinkets to starships. When rolling randomly, all worlds with preindustrial technology get a -1; a spacefaring or higher technology get a +1. A plan-etary population below 1000 gives a modifier of -2, and population less than 1 million gives a modifier of -1.
SPECIALTIES
Many worlds have some resources which are the result of particular local conditions and do not occur elsewhere. They may be natural products or items made only by one culture on that world, or luxury items like a unique mineral water. On a roll of 6, a planet has some special resource; the GM gets to decide what it is.
P
lanets are not the only things one can find circling a star. There are asteroids and comets, space rubble which may turn out to be more useful in some ways than planets themselves. Intelligent beings can construct space stations and habitats. And extremely advanced civilizations may construct really huge structures bigger than worlds.ASTEROIDS
Asteroids are small bodies orbiting a star.
They range in size from a kilometer across to 1,000 kilometers in diameter. All asteroids are airless, and have a surface gravity of 0.01 G or less. They have no surface water, but may contain deposits of ice.
In the Solar System, the asteroids are most common in the Asteroid Belt, a loose collection of bodies orbiting between Jupiter and Mars. Any planetary mass result of 0 during planet generation indicates an asteroid belt. Other star systems may have multiple asteroid belts, and young stars won’t have anything else.
The exact composition of asteroids varies.
Some are stony-iron bodies, composed of rock and metal with little in the way of volatiles. These are most common in the inner system (the Red, Yellow, and Green zones), although they can be found any-where. Carbonaceous asteroids are rich in carbon and volatiles, though rock and metal still makes up the bulk of their mass. Carbon asteroids are most common in the Green and Blue zones. In the outer system (the Black zone), comets predominate.
The structure of asteroids also varies. Some are simply huge single chunks of rock or iron, possibly with a coating of dust pulverized by eons of mete-oroid impacts. Others have been shattered by large impacts, or formed by low-energy collisions, and so are really just a collection of fragments loosely packed together.
Humans operating on an asteroid face several hazards. The surface of an asteroid is essentially
“outer space,” with no protection from cosmic rays or solar heat. (See page 281 for conditions in space.) The low gravity means staying on an aster-oid’s surface can be difficult. On small bodies (up to 20 kilometers or so) a vigorous leap can send one into a long ballistic path, sometimes circling the entire asteroid. Explorers and workers need tethers to keep from “falling off” into space.
The surface of an asteroid is likely to be a mass of powder like Moon dust. In the minuscule grav-ity, any motion quickly raises a cloud of obscuring dust. Each Phase characters must make a PS:
Zero-G Operations roll, or a DEX Roll at -3, to avoid kicking up dust. On a failed roll, the character is surrounded by one hex of dust, which functions as Darkness to Sight Group (and, depending on composition, possibly the Radio Sense Group and senses like Sonar). The dust settles in 6 Segments unless the character fails another roll. In a battle situation, characters may choose to kick up a lot of dust deliberately, to block laser weapons and sen-sors.
Their low gravity makes asteroids attractive for space mining and manufacturing because there is no need to waste much energy hauling mass out of a deep gravity well. Asteroids with ice deposits could draw colonists, tunneling into the rock and farming under domes or bright lights.
To determine if a system has asteroid colo-nies or bases, the system must either have a planet with spacefaring technology, or the system must be claimed by a spacefaring civilization. If either of those is the case, roll 2d6-11 and add 1 for each