We start already with a big world: you flesh it out and pore over the details and develop it into the grandiose epic you know it ought to be. This shouldn't reduce the mystery, though. Just as soon as you've established rules, you should showcase those things that run counter to them- things that would be called exceptions if it weren't so that they are myriad, vastly outnumbering you in any of the wild spaces that exist beyond the little bubble you were so comfortable in.
This is the sort of game I like to run, play, or just idly daydream in or about. My posts have had a bit of a gap recently, and one of the main things stewing in the interim has been myth and ritual, and more specifically how to get the quality of those things across in-game. The character I use in my ever-to-be unfinished short fiction is driven to know more about the gods, goddesses and otherworldly forces that drive things behind the scenes- it is only natural, then, that I try to bash out some broadly corresponding rules.
I've been reading a lot about myths and dreams, and one of the notions that comes up again and again in the Jungian-derivative essays and various chaos-magician writers' works is that a ritual is a kind of theatre, acting out myth-themes to please or entice some supernatural being or force. I like this idea of ritual or myth as a narrative, some pattern which a given being is almost compelled to interact with.
Qualities for Otherworld Denizens
The sphinx is powerless to resist riddling any intelligent being she would eat. The god of thunder is drawn like a moth to a flame to any amorous activity that resembles his raunchier conquests. A summoned devil abides by a certain code of conduct- providing the summoner remembers to follow suit. These rules are not enforced by the physics of the universe or the mechanics of magic, they are the entity itself's weakness to the very fabric of their reality- narratives. A creature of this kind would have the quality Addicted to Narrative.
The dignitary from Faerie is easily coerced by bargains and trades. The High Priest of Banzion will always find himself inclined to excess and waste. A sorcerer with infernal blood finds herself absorbed by scenes of suffering. These creatures, through relation or extended interaction with supernatural forces and places, have taken on something of those forces qualities. They have gained the quality Susceptible to Narrative.
The quality Addicted to Narrative is really reserved for NPCs, or perhaps as a temporary curse on a player, since it limits agency in the game. Susceptible to Narrative is a more fitting quality for a player character, offering rewards and drawbacks for certain actions performed or avoided. When a character encounters a scene playing out that the GM determines to be a narrative they are susceptible to, they can choose to resist or give in to the urge. Resisting requires Testing their Luck. Giving in will reward them with a Luck point.
What do you think? Is this stuff better just roleplayed, or is a bit of a guideline rule helpful?