Constitution - Con
Constitution denotes life force - it determines how much damage a character can take before dying, how they resist poisons, shocks and diseases, or how long they can run or fight.
Constitution is very important, and especially in a hostile environment it means the difference between life and death. Directly related to Constitution is Endurance, which we will discuss in the part of the rules dealing with damage, fatigue and healing.
Constitution also shows in less direct ways. A character with low Constitution will tend towards comfort, may be sick more often and certainly tired, which will affect their behavior. A tough character, on the other hand, may demand high performance from themselves and those around them.