A lot of the people playing this game are already fans of D&D, particularly 5e, for obvious reasons. And I see a lot of posts here trying to get the game to feel more like D&D. But should it? Should we try to get the game to be as close as possible to D&D? I don't think so.
Larian obviously loves the Forgotten Realms. The depth and flavor that love brings to the game is fantastic. But D&D is a very different game than anything they will produce. Half the fun of D&D is being able to say whatever you want, do whatever you want (with consequences of course), BE the hero. Literally. Your brain is directly transplanted into this mythical figure's body. The world is open to you. That's not something that ANY videogame can replicate. There will always be restrictions you can't overcome, boundaries you cannot cross.
But beyond that, there are mechanics in D&D that I don't think can be easily mimicked in a videogame. The best example of this is probably the Divination Wizard. For those of you who don't know, the Diviner gets to roll two d20's at the start of every day and keep those rolls. He can then substitute those rolls for ANY OTHER ROLL. Enemy rolls a crit? Nope! Substitute that nat 20 for one of the other rolls you have. Ally fails a critical save and is now mind controlled? Nope! Now he rolled a 19. It's a great ability.
Now, think about the mechanics of that going on behind the scenes. EVERY time ANYONE rolls a d20, the Diviner has to chose if he wants to substitute that roll for a different one. Most of the time, he doesn't want to. From a mechanical perspective, the Diviner is asked each time a d20 is rolled, "Wanna swap it?" That just won't work in a videogame. Now you could easily just say that the Diviner only gets to substitute the rolls you make in dialogue, but that is hugely limiting. Probably necessary though, because I don't think there is any way to ask the player EVERY TIME and not have it be super annoying and slow everything down.
Reactions are another example. Something happens and you decide if you want to react with X. Now, X could be an Opportunity Attack, Shield, Riposte, Counterspell, etc. There are a lot of reactions in 5e. Are you going to stop the action whenever that happens and ask the player "Wanna do something?" You could, but that would be very tedious. Ultimately, I think it will just HAVE to work differently.
When you think about it, every D&D game has had to compromise staying true to the source material for the sake of a better experience. The original two Baldur's Gates did it. Neverwinter Nights and NN2 also. Things like real-time combat (or as close as they could), and attacks of opportunity working differently were decisions the designers made because they thought it would make the game better. And I think it did.
I'm all for a game that is based in D&D. The guys over at Larian have shown their passion and dedication to the world of the Forgotten Realms and I love it. But differences will have to happen. We can't ask that every single aspect of the game be the way D&D 5e does it. It just won't work.
And maybe that's a good thing. I have played a lot of D&D already. Something similar but with that Larian spin sounds great to me. Yeah, I may still get slightly annoyed whenever my Magic Missile which is supposed to be unerring hits my friend in the face instead, but I'll get used to it. I want to see what their take on D&D is, not just play more D&D.
P.S. Old Firebolt = best Firebolt