Single handed attacks only cost 1 AP? Pretty sure my sword-and-board warrior always spent 2 AP when swinging that axe of his.
Afaik, single attacks cost 1 AP only when they are carried with small weapons (daggers), otherwise it's still 2 ap per hit.
No, single handed cost 1 AP, while having nothing equiped in secondary slot.
Shield or dual wield, add 1 AP cost.
