like obviously most good stories should be fuelled by character. but i mean like... specifically when the author writes without any sort of scene outlines, without any real plans for the overarching plot and character arcs. they just let the characters decide what to do, drive each scene forward with the instincts and reactions of each person. i hope that makes sense? and if it does then, yeah, is there a term for it?
Yes, this is called "Discovery Writing", and Stephen King is one practitioner.
In this method, we develop an interesting character (or several of them), set up their normal world, and typically we have a "what if" scenario we trigger. A weird situation we have thought up.
Something happens to our hero, a triggering incident, that forces them out of their normal world and on some journey, to either recapture their normal world, or perhaps create a new one.
But the story is character driven, we let the plot develop as it goes.
I write this way, and it works great. When I first tried to plot out a story, I got bored with writing, because I felt after developing the plot, the excitement was gone and I was just doing grunt work.
Also my characters, as the actual story progressed, began to feel artificial; like I was forcing them to say and do things "out of character". I could not finish a story.
I tried discovery writing, and that did the trick.
I do write with the 3-Act-Structure (3AS) in my head; it breaks down a story into about 16 turning points of approximately equal length. So as I am writing, I know about which segment I am in for the 3AS, and the "direction" I should be writing in.
For example, in the first half of the story, things should be getting more complicated, in the second half, things should be getting less complicated. Likewise, we need to beat up the hero in the first 3/4, we want them to keep getting knocked down, and (heroically) getting back up. They aren't a "hero" if they aren't getting (metaphorically perhaps) kicked in the face repeatedly and getting back up to soldier on anyway.
But unlike the plotters, precisely how these things happen, we leave to chance and where they have ended up, based on their personalities.
by about 3/8 of the way through the story, I start getting ideas of possible endings. These often change 4 and 5 times before I actually finish, but I write them down and treat them like compass directions for where the story is headed.
If I think of a better ending along the way, then I make sure what I have written so far is compatible with it, make any changes I need to make to allow it, and then again just use it as my compass direction for where the story is headed.
Discovery writing creates more rewriting than plotting, but I find the published discovery writers have far, far better and more natural seeming characters than the plotters do.
At least, I prefer them.