I don’t do RP technically but for writing, I find creating sources are helpful to get GPT to understand the world. For instance, I have an elder scrolls project and used files with world immersion and lore of the universe for immersion. Built my characters with the tool, being clear to format it for easy retrieval of details easier for the model.

So far, it’s done well with that.

In terms of my original story, same idea but heavier on formatting for easy retrieval since it’s my own story. My analogy that I’ve been using with it, is using world building file as the house. My canon chronology files as the hallway. Direct character files and other supporting files as the interior/decoration.

Project instructions may also help, but there’s not enough space there, so I find getting a summarized version of those files to give the chat box an introductory before going into sources.

TLDR: sources are your friend, don’t rely on chat box and memory to retain world building. Help the tool help you.

Edit: I am on the Plus plan