I get the whole fire, ice, shock, ect. damage..but what exaclty is shadow damage supposed to do?
What is shadow damage?
This is a fantasy game with fantasy elements, thus Shadow and Elemental damages. I think it's something like weaponized darkness and negative thoughts.
Basically, there are 4 types of damage, piercing, elemental, normal and shadow. You know how there are different monsters in the clockworks or missions? Each monster deals a certain type of damage and is weak to a certain type. For example, the jellies are weak to shadow damage and take more damage with a shadow weapon than a piercing weapon because jellies resist piercing damage.
Think of it as a weakness type of damage system thing.
according to biotech hahn, shadow energy is: ''generaly caused by concentration of negative energy. Attacks that inflict shadow damage range from the psychic maniplation of that energy to physical attacks with weapons made of dark matter'' (a mineral)
thats in-game story, of course.
fire, shock, and freeze are status affects, not damage types. They do deal damage, but they aren't of the 4 main types (normal, pierce, elemental, shadow).
There are four categories of damage: Normal, Piercing, Elemental, and Shadow. Think of them like Rock, paper, scissors, except they can all defeat each other. That is what's in the weapons. In the armor, you can have resistances against rock, paper, and scissors. They don't interact with each other, but rather the resistance against them or the lack of resistance.
For a more thorough explanation: http://wiki.spiralknights.com/Damage