Interesting topic for a thread. I read quite of bit of this thread. I've been busy but I wish I had the time to respond sooner. Just seems like this thread has generated a lot of pointless bickering and edition warring.
To me, this primacy of magic thing is a red herring. It has absolutely nothing to do the essence of D&D. It is more of an implementation concern and not really about the essence of the game.
To me, the essence of D&D is the following:
- You the player get to explore a fantastic world filled with dungeons, ruins, monsters and magic. Your character is an avatar/playing piece that allows you to insert yourself into this world.
- Your character has abilities that help define its role and how you contribute in the game. Classes provide strong archetypes for what you do in the world. The character class becomes a lens through which you see and interact with the fantastic world. Playing different character classes changes the lens and allows you to experience the game in myriad different ways.
- The game is a cooperative event where you get to share an experience with other people and contribute to the success of the group.
- The player at the table holds the power in a game, not the character. Character capability and player capability are two completely unrelated concepts. The character is just a playing piece for the player to exert their agency on the game.
If you asked me to describe a rules element that dictates the essence of D&D, I'd have to decline. Its not about the rules, its about the approach and the experience at the table as you play it.
I've played and run pretty much every edition of D&D ever released. I've enjoyed playing them all. I have my preferences and I try really hard not to talk in absolutes (I don't always succeed at this).
It is kind of frustrating to hear terms like "not D&D" or "its just a video game" or "only played because of nostalgia" or "it's just old and busted rules" for different versions of the game. I honestly don't care who plays what edition. I like the editions I like and I'm glad others like the editions they like.
I really don't think the implementation really matters with regard to the essence of the game.