Fatigue is the natural result of overwork and not enough rest. It can also be induced by various herbs mixed into potions which interfere with the body's basic processes.
Fatigue I: All d20 rolls are considered Hard
Fatigue II: Fatigue I, Slow I
Fatigue III: DISADV on all d20 rolls, Slow II
Fatigue I: 1 Earth, 1 Air, 1 Water
Fatigue II: 2 Earth, 2 Air, 2 Water
Fatigue III: 3 Earth, 3 Air, 3 Water