Amour Class is the defensive resource against the melee rank of an opponent, plus any 'To Hit' modifiers by a weapon. This is different from dodge which requires an additional and separate calculation. This is also different from damage resistance (DR), which mitigates health and fatigue damage.
Armor class can be increased a few ways:
- Indirectly by anything that increases dexterity.
- Cumulatively with equipped items that list an AC stat.
- The spell Blur Sight increases the Armor Class of a caster by 60 points regardless of aptitude.
- The spell Shield of Protection increases Armor Class by 10 to AC, again regardless of aptitude. Note that this also increases some resistances and that is scaled by aptitude.