We're using the Unearthed Arcana Vitality rule. My level 3 Fighter has a 15 CON and a normal HP maximum of 28. Courtesy of a bad wubba wubba fireball, I'd been reduced to 0 HP and 9 Vitality.
Since then, I've received healing to bring myself up to 17 HP (all good so far, as my effective hit point max is 19) but now I want to use a Hit Die to heal further. This ordinarily wouldn't work because of my reduced HP maximum, but if roll higher than a 10, this might offset the Vitality loss.
The ambiguity comes from the wording:
Effects that restore hit points have no effect on vitality. However, a character with maximum hit points who receives healing instead restores 1 vitality for every 10 points of healing.
Does using a Hit Die to restore HP work for restoring Vitality?