Thick and Thin Atmospheres Tables

[(Psi)SeveredHead]

http://p209.ezboard.com/fthegamemechanicsfrm16.showMessage?topicID=156.topic

THIN ATMOSPHERE
Planets with thin atmospheres have less oxygen per breath than the standard Earth atmosphere. Many thin atmospheres are the equivalent of being at a high elevation on Earth, such as on top of a mountain or in the upper atmosphere. A creature exposed to a thin atmosphere must succeed on a Fortitude save (DC 20) every hour. On the first failed save, the creature is fatigued. A fatigued creature that fails a subsequent save becomes exhausted for as long as it remains in the thin atmosphere. After 1 hour of complete, uninterrupted rest in a normal atmosphere, an exhausted creature becomes fatigued. After 8 hours of complete, uninterrupted rest, a fatigued creature is no longer fatigued.

THICK ATMOSPHERE
Thick atmospheres are those that contain a more dense concentration of certain elements, like nitrogen, oxygen, or even carbon dioxide, than the standard Earth atmosphere. These dense atmospheres sometimes contain a different balance of elements, while others simply contain a higher number of gas particles in each breath. The effects of exposure to a thick atmosphere are similar to those of a thin atmosphere (see Thin Atmosphere, above), except the Fortitude save DC is 15 instead of 20.

 

[Turanil]

I am currently reading a book on creating alien races that are scientifically plausible. In this book I just read this:

During the time of dinosaurs, Earth's atmosphere was denser, and also contained a greater proportion of oxygen. This sole fact is what allowed huge creatures such as dinausors of 30 tons or flying pterodactyls to exist. I f they were revived nowadays as in the Jurassic Park movies, they would be in fact unable to survive, as the atmosphere would be too thin for them to breath effectively.

So, a planet with a thin atmosphere is not likely to have huge creatures wandering on its surface. Then, since there is a minimum size necessary for a developped intelligence, a too thin atmosphere would preclude native intelligent species.

 

[ragboy]

I am currently reading a book on creating alien races that are scientifically plausible. In this book I just read this:

What book?

 

[Turanil]

What book?

This one (I suggest to get a look at my review though, the one with only two stars).