In the original Horizon Wars, players tracked damage in two ways: first, and best known, was the feature by which elements suffered attrition to their stats from incoming fire; and second was the "damage track" - a tally of exactly how much damage the element had suffered.
These two things have been made a little more separate in Horizon Wars: Midnight Dark. The attrition of primary stats is still a feature and that's now "damage". The amount of damage an element is carrying can go up and down quite a lot. Meanwhile, we also have "fatigue", which replaces the old damage tally. Fatigue becomes a lot more important in Midnight Dark. In the original rules it basically just told you how easy or hard it would be to recover from damage. But in the new rules, fatigue will tell you a lot about how easy it is to issue orders to an element and how much an element can do in a turn.
Synthetic elements, like this drone, don't suffer from fatigue the way other elements do
An element that reaches its fatigue limit, it becomes exhausted. Elements that are exhausted cannot be given more than one order per turn and lose access to a number of key special abilities as well as the ability to secure objectives. The more a force is exhausted, the slower and less responsive to orders it will become.
Fortunately, there are a handful ways for players to reduce the fatigue of their elements, one of which is combat drugs: a dangerous upgrade that inflicts damage in return for reducing fatigue. Another way to deal with the exhausted state is to field synthetic elements that never get exhausted (however, they do still take fatigue, and other effects of fatigue still affect them like everything else). And a third way is to add a hero to your element, and I'll talk about heroes in more detail in the next blog update, but heroes can perform an "heroic sacrifice", which removes the hero (they aren't necessarily dead) but removes certain conditions or reduces fatigue to keep the element fighting on, its members motivated to greater heights by the example of the hero.
Because managing the ability to deliver orders is vital to your tactical planning, the management of fatigue will also be essential - pushing an element to its limit, only to call for an heroic sacrifice at the vital moment that will allow the element to claim victory against the odds!