Planet Types

Biology, Geology, and Meteorology require you to specialize by “planet type,” as does the “Physical” specialty of Geography . If you do not specify a planet type, your native planet type is assumed – so if the campaign will never leave your home world, save space and just write “Geology,” “Biology,” etc. GURPS sorts planets into six broad categories for these purposes.

• Earth-like:
  Essentially, all habitable worlds.

• Gas Giants:
  Jupiter/Uranus types.

• Hostile Terrestrial:
  Venus types.

• Ice Dwarfs:
  Comets and small moons composed almost entirely of snow or ice.

• Ice Worlds:
  Rock worlds covered by a frozen “ocean.”

• Rock Worlds:
  Most moons, asteroids, etc.

Unless otherwise specified, all planet-type specialties for a given skill default to one another at -4.