In RL there is a biological difference between fatigue and tiredness.
When you are fatigue, you`re organism has an energy-deficiancy. The muscles dont have enough ATP or the oxygen-level is too low.
But tiredness is a phenomenon which is linked with the periodicity of the body. The whole organism is controlled over numerous time emitters. The origin of this can be located a.o. in the movement of the sun and the tides.
So there are different types of periodes: daily, monthly and annual ones.
The daily one is the one which matters here.
There have to be time to sleep in a day, although you didnt work hard.
This should be taken in account, when discussing this topic. This difference in RL could be taken into the game by following:
There are separate measurements of fatigue and tiredness.
Fatigue (simalar to stamina now) has an effect on the damage done, the velocity and range a char can go. When a char is fatigue, he can only walk slowly and do less damage, but gets full xp by doing things.
The level of tiredness is (comparable to jagged alliance 2, if anyone knows) the max. amount the stamina (fatigue) can be restored. Tiredness is only related to the time a char is awake and \"drugs\" like coffein or other push-ups

In PS it also could affects the amount of xp (in percentage), the probability to hit or to succeed in other activities. Everyone who once was really tired in school, knows what I am talking about.
What do you think about this?
Bye,
amogorkon