Quote Originally Posted by LudicSavant View Post
"That triceratops has only 13 AC. We'd better take care of it before that Fireball-slinging mage!"
- No PC ever.

When you don't know how to play an effective tank, what you often get is a turtle. Whether the turtle's shell is made out of HP or AC makes little difference.

The difference between a tank and a turtle is that a tank does not rely on enemies making a major tactical error to do their job. A turtle says "gee, I hope the enemy decides to attack me." A tank says "If you ignore me, you will lose."
Reminds me of the 3.5 monk with some vow of non-violence or something. He thought he could go defensive and attract enemy attacks with his silly-high AC, but they just ignored him and walked by. If he attacked them, lots of his abilities collapsed, so he just danced around doing nothing while everyone else got killed.