When you are doing hard and difficult skills during a combat, your vitality (shown by move points) will decrease. There are several spells that could restore your vitality (such as revitalize), but some tasks are so difficult, that your body gets very tired from them more than these spells could restore. Fatigue will show you, how much tired your body is. This value is very important. For each 500 fatigue your strenght and dexterity will be reduced by one. And if you reach a critical level, you can even die on mortal wounds. The best way how to get rid of fatigue is to rest. Revitalizing spells also reduce it, but not very significantly. You can add fatigue to your prompt string. %AT - text mode (none-low-medium-high-very high-OVERKILL) %AF - flag mode (f-f-f-f-f-f) %An - fatigue value divided by 500 %AN - real fatigue value