Armour

[Cret]

As a mage that wearing armor will hinder casting. Or as any other class wearing armour heavier then trained in will hinder skills.

What I dont see is why I would be failing at both when this is my score sheet.

head 24 (none)
body 24 (none)
arms 24 (none)
hands 24 (none)
waist 24 (none)
legs 24 (none) Spell Failure: 10%
feet 24 (none)

[Gwain]

Does it take into account natural armour?

[Nylo]

The main reason I've found for this, is when you have an item in a wrist slot, such as a bracer, that's set as armour. I haven't seen items like that for the other jewelry slots, ears, face, etc., but those are also possible.