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Mapcraft - Fantasy map designer

WorldGen - SciFi universe generator

Mapcraft Web - Web based fantasy map designer

All code for the project is released under the GPL, and is copyright Samuel Penn.

The text on this wiki is dual licensed CC-BY-SA and GPL.

You can contact the author at



Within a billion years, EoArean worlds rapidly cool and settle into a MesoArean stage. The atmosphere may still be reasonably thick, but won't stay that way for long. As the atmosphere thins, so any surface water will evaporate and oceans will begin to dry up.

Sometimes complex life will form, but rarely develops beyond the oceans or basic lichens and mosses on the land.

This stage can last as little as a hundred million years. If the world manages to maintain geological processes that keep the atmosphere topped up, then it becomes an Arean Lacustric. If it is too close to its star, then it may become an AreanXenic. Normally however, the atmosphere thins, the seas evaporate and it becomes a cool Arean desert world.


Similar to Arean, with the addition of surface water and a thicker atmosphere.

Supported Features

  • EquatorialRidge - east/west mountains along the equator.
  • PolarRidge - north/south mountains.
  • GiantCrater - huge crater near the equator.
  • HeavilyCratered - many more craters than normal.
  • SingleSea - single sea in one hemisphere.
  • EquatorialSea - all water near the equator
  • Smooth - no mountains, few craters.


2d6 Life level
2-4 None
5 Protiens
6 Protozoa
7 Metazoa
8-10 ComplexOcean
11-12 SimpleLand


Silicate, with some Ferric. Maybe Krysite and Magnesite as well.

pcl/mesoarean.txt · Last modified: 2015/02/04 22:39 (external edit)