Taking no damage at all, I think, would be counter productive. It would often make it hard to realize you even made a mistake or that you failed to dodge something.
Learning from your mistakes is in my experience one of the fastest ways of learning, you make a mistake, then quickly realize it was a mistake and try to avoid it moving forward. Of course most people will make the same mistake multiple times, but eventually you’ll be pretty consistent with it. Even experienced players like myself who have done hundreds of level 15 shards and hardmode raids still make mistakes and keep learning from them, that’s just part of the game and one of the things that keep me coming back, that urge to improve.
Now if you didn’t take damage, you would often not even realize you made a mistake and so you loose a big part of the learning loop. Taking damage is the primary way you know you f***** up in most cases.
I think, the way dungeon shards work already accomplishes more than what you are suggesting would. You start out with low level shards that are pretty forgiving and allow for minor mistakes to be made so you can learn and get a good feel for the dungeons. Then you level them up and gradually get higher and higher, requiring more and more skill, accumulated from repeated mistakes and practice. In the case that it’s too much for the group and you fail you get a little set-back, but you can still get gear if you complete the dungeon after the shard breaks.
As for raids, kinda same thing, there’s an easier variant of each raid, normal mode, and a harder variant, hardmode. Normal mode is the practice version for hard mode, lower damage, more forgiving, but mostly the same mechanics. When you go on your first raid, no-one expects you to understand everything right away. You will make mistakes, but more importantly, you’ll learn from those mistakes. First few times may feel like you-re being carried, but that’s alright because you’ll learn and improve and eventually be one of the people carrying others and teaching others.
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