Tank mechanic? You mean the "taunt" ability?
Contrary to WoW, in DnD they did in a smarter way : cover system + attack of opportunity and other warrior feats that allow to protect the nearby mage. BTW, for some classes they do have "taunt"
Yes, I was being sarcastic.
DnD doesn't have "tanking" in the traditional sense. As you say, it is more about standing next to enemies and using attacks of opportunity to threaten NPCs into not running passed you. Or just doing so much damage the DM reasons that the enemies will focus on you over the backline.
It was a joke to point out that DnD doesn't adhere to strict class roles in a group. You can get by without a healer or without anyone to do the tanking. Party composition more boils down to covering one another's weaknesses and making sure you have tools to deal with different threats.
