Firstly, this sounds more like play-acting than improv. Secondly, D&D doesn't really support this, it doesn't do anything at all about this. It's rather neutral on the concept. You can play act all you want and it doesn't make much difference than if you speak of your character only in the 3rd person -- game doesn't care about these things.
Improv is all about the "yes, and..." It's about being able to be surprised by the other participants, and not being able to guess how the scene will unfold. This isn't the normal approach, by a far margin, for D&D, which features the GM allowing or disallowing success on actions and largely controlling the direction and pace of story development. If you do manage to get into some real improv, D&D doesn't offer any support for doing this because almost all of it's resolution mechanics start, end, or rely heavily on "ask your GM."
You're looking at improv as the actual artform and performance... and by that measure you are correct-- no games at the table can recreate that.
But I think we all understand where we are coming from when we are saying "improv" in this scenario-- the players do not have any script or write-up to what is going to happen, they have to naturally act and react off of what is presented to them. They have to invent their response. And usually, that response is done "in character"-- IE in a manner that they think their character would respond with, not necessarily how they-- a 21st century game player-- would respond.
When (general) you play a regular board game, (general) you usually ARE responding as yourself. You see the board and what has happened, and you make a decision using your own knowledge and reasoning to do something to further your goals in the game (usually to try and win.) That does not tend to include making choices for or as someone else. Now the same
could be said for D&D-- you could make a "character" that is just a series of numbers and play the game as you would your typical board game... making decisions off of what the DM presents you as yourself. Perfectly doable and perfectly acceptable per the rules. And I don't begrudge anyone who chooses to engage the game in that way.
But I do think (general) you are selling yourself short and missing a strong component of what D&D (and all RPGs) give you if you do that. The game is designed for you to NOT play "yourself", but to act and think as someone different. It is one of the strengths of the game in my opinion. Getting into a different mindset and creating and making choices that are not optimal for you (the player) to accomplish your goals of "winning" per se, but instead are what is right for the character and the character's journey. And more often than not, what the character wants and what the players wants aren't the same thing.
But people are absolutely right when they say that games like
Fiasco are closer to "true improv" than D&D is. I don't disagree with that assessment at all. And quite frankly the main reason is exactly due to the convo in the other thread about whether D&D is 90% combat-- the game definitely has a large board game component to play. So with that being said... I certainly also understand the other side that says that since so much of D&D is designed and geared towards board game play, why not continue to lean in that direction? And I can't argue with that opinion, it makes complete sense. Which is why I try to always make the point that anything heading the other way-- towards more of a theater and improv focused style... is just my
hope for what can happen... not that I think it NEEDS to happen. My HOPE is that more and more people begin to embrace the kinds of story-focused styles of game that yes... Matt Mercer and the Crit Role crew... are playing. Because that way requires less "rules" that need to be "balanced", and thus opens players up to not being so gosh-darn nitpicky and argumentative. And every time I see a thread that has like four people going on for 40 pages arguing back and forth past each other about what "the books say!"... I just know in my heart that those mindsets are not doing the game or the gaming populace any good. Getting that wrapped up in "the rules" and "what the rules say" is missing the forest for the trees I feel.
Then again, that's just my opinion... I could be wrong.
