[RPG] In Wild Shape for druid5/barbarian1, how does unarmored defense work?

armor-classbarbariandnd-5edruidwild-shape

Background:
My Hill-dwarf character started out as a barbarian. When his clan battled the undead hordes, he barely escaped with his life. He was taken in by a druid, and discovered a higher calling. Druid society is a contradiction in terms, except its not, because druidcraft and druidic exist. They aren't normal norms, but they exist. He grew up to his current level, and was sent "walkabout". He has strength, but he is also a bit naive. So he is out adventuring, trying to be meaningful in the world.

The problem:
I'm trying to figure out what his role in battle is. Back-line (heals, spells), front-line (tank, …), or what? In our game (Storm Kings Thunder?) we are going up against giants. We took on a pair of fire giants. We took on a half-dozen hill giants. Those things lay out damage, and wild-shape doesn't seem up-to-par. I'm trying hard to not die.

The question:
Does the barbarian unarmored defense, which is class and not race based, which adds dex bonus and con bonus to race base AC, apply to wild shape?

Thoughts:
There is an argument to be made that non-hominid forms might have a very different unarmored defense than anthropomorphic forms. An effective unarmored defense for a dire wold might look very different from, and be non-intuitive to a non-wolf.

Possibly related questions:

  • While using Wild Shape, do I use Unarmored Defense or the creature's Armor Class? (The 10 is the base AC for human/dwarf/elf. A wild-shape creature, such as a wolf, has a higher base AC. Why would the wild shape bonus for a base human AC apply? If the wolf has higher dex, for instance, and the character in that form is more capable of exploiting it than a base creature of that form, which is the essence of unarmored defense, then why would the unarmored be based against 10.) I'm asking for justification, not just "what is the rule", and in that way my question is meaningfully deeper than the other one.
  • Does natural armor stack with unarmored defense?

UPDATED QUESTION:
The answer is given that you can choose the best between the creatures or 10 + dex + con.

Where does the "10" come from, and why is it the correct base?
What is the "physics" that makes the wild-shaped druid retain the 10?

One thinks of the "mean" for (barberian) humanoid AC as 10. If Dex and Con were bad it would be lower. If they were great it would be higher. Why would the "mean" for Spider not be 14? As a race they are fast, but a slow spider might have lower, while a very fast spider might have higher.

Best Answer

Unarmored Defense works in Wild Shape

Just like your linked answer states:

You retain the benefit of any features from your class, race, or other source and can use them if the new form is physically capable of doing so.
(PHB p67)

Non-humanoid forms do have a different AC because of Unarmored Defense

In human form you use your Dex and Con for the calculation, in Giant Scorpion form you could use AC 13 (Dex 13, Con 15), of course you are better off using its natural armor (AC 15).

Why don't you add the Dex + Con to the beast's usual AC instead of 10?

Because this is not what is written in the rules.

You can't argue against RAW. You can argue with your DM to change the rules, but then it is a homerule.