As a prelimenary to the topic, I made this post at a couple of video game subs. Its pretty much the gist of my question except now instead applied to tabletop RPGs.

Does an author write the whole basic script and then the head of the development team makes changes as he sees fit in the same way movie directors change lots of stuf from a screenplay to fit his vision? Or is it a reactive process by which the author makes changes every step of the project in response to what the development team is currently doing like changing an entire game level's plot in response to a new weapon the dev team added to a character's arsenal last minute just how like TV writers will alter an entire season's plotline because an actor got sick and couldn't be on set? Like TV do multiple authors work on a single game with a head in charge similar to a showrunner? Or is it more like a single author overheading the whole thing as common in book writing? In between with several writers coordinating as common on in comics? Or constant change of people employed as typical in film?

What other details are involved in video game writing beyond the tidbits I asked about above specifically the process and the specific steps as the game develops?

So I'm wondering how they tackle the writing process in Pen and Paper Rolepaying Games?