I think you recover the Vitality Dice too often. Perhaps turn some of the speed of getting them back into a feat (recover action).
The idea is that they represent your stamina and footing. It seems like they should come back pretty fast. Do you think it's too fast conceptually or mechanically?
You have Defense 10+DEX+Shield
You have DR = to your armor -10.
You can reduce damage with your VD when you are hit 1dX+proficiency (X=HD type).
I would say you could use multiple VD per round.
I am pretty sure this is all the same as I have it. You can use as many VD as you have available.
I would change the VD to be Dodge Dice and have them be 1dX+DEX. Medium and heavy armor lowers DEX, this would give a reason why to have light armor, you can dodge better.
Pretty much the only I didn't do this is because Dex is already the golden-boy of stats, but I agree that Dex would be on-concept here. I used proficiency instead, casting VD and the bonus as generic skill at not dying that all adventurers pick up throughout their career. This way does suggest that a high-level character, even a wizard, has picked up a great deal of acumen at avoiding danger. I'm not sure if everybody will like that, but I just can't justify making Dex a required stat for all but a few heavily armored classes.
You have wounds = to your CON score.
I would divorce the CON score from the wounds. So that you do not have to calculate stuff as your CON score goes down.
I would eliminate the CON checks on short rests and long rests. Just say on a short rest you can get back 1 and at 10th you can get back 2. On a long rest you can get back half or if playing in a more heroic game you get back all. Recover wounds 1 per day with a medicine check recover 2. Cure wounds spell recovers 1 wound per level used. Healing word recovers one dodge die.
I echo [MENTION=6788973]MostlyDm[/MENTION] and his concerns, here, about Con not being used enough. If Con isn't used for durability or recovery, then what is it, conceptually? I cast it as a character's physically resilience, how quickly he or she bounces back from injury, how hale and hearty he or she is. I agree that the healing needs work, but I think it needs to tie to CON.
I am not married to CON damage for wounds. I think it has its merits, but I understand that it has its drawbacks as well. Does the penalty chart for ability modifiers even go all the way down to 1?