Fallen Enchantress gives you basic information about your weapon and armor, summing up your attack rating as "8 cutting," and your defense as a straight number like 24 (though some armor gives extra bonuses against some attacks; chain mail has a bonus against cutting damage, for instance). Unfortunately, the in-game tutorial is pretty useless; it will get you started, but doesn't give any fine details that would help you optimize your play.
How does a weapon's attack rating relate to how much damage you do against an unarmored opponent? How does armor affect the damage? Is elemental/magic damage calculated differently, i.e. can you bypass heavy armor by using fire bolt? If an attack has multiple types, like 9 cutting and 2 fire, how is the damage calculated?