Neonchameleon
Legend
No you don't need all the prep. It's just useful.None of that really talks to my central issue. My issue was that introducing backstory on failure interferes with prep so why bother with the prep?
The prep is meant to pin things solidly in place, Specifically the backstory and personality of the primary npcs and their relationships to each other, (and the pc's) including what they're doing and plan to do in the form of clocks. And the resources they have and can bring to bear (such as weaponry and gang size).
You need all that stuff in place so you can roleplay the npc's and decide what decisions they would make in response to events.
introducing loads of stuff that ret-cons or interferes with the above seems contradictory.
If you look at actors preparing for a role in a TV series they don't get all (or even many) of the scripts before auditioning or shooting the first season and surprise reveals are a thing. This doesn't stop them preparing what they think is the backstory to add depth to their characters. It helps inform them how to act and react to things but only what the script writers write in the scripts is actual canon.
Prep is at the same level for the MC as it is for series actors. It's secondary canon used to inform but only what is filmed or happens is actual canon. And some actors prepare more than others but almost all good actors do some prep beyond reading the script.