So the vermin thing definitely works, but only really reliably in confined spaces. I dont think ill go with that as a primary means of acquiring spells, but maybe an option?
Ive decided to move nosferatu off the caverns list, but i might make other changes instead. They appear on almost 100% of embarks, despite being frequency:1 and having all these other cavern critters available. And theyre dangerous and annoying enough on their own to warrant sealing off the caves.
I think its just time to give dwarves the magic they need to keep cavern critters from overwhelming a fortress without having to wall off the map edges. For that i had various idea like spells for killing particular species or cavern critters in general. But i also thought about "ensnare" spells that paralyze (and add nobreathe to) cave critters that attack your dwarves for a day or two.
And then i wanted to give dwarves other powers like supertough skin when underground or spreading euphoria when drunk, if they learned those abilities. Or adding nonausea/nobreathe when appropriate
But theres a bigger question; i wanted to allow innate, natural abilities or curses again. I thought about using castes but i dont want to go and edit every single race to add castes and everything be dependent on that framework. But i could use a syndrome to have a similar effect, without any further edits to the race itself.
So i thought, how can i reliably get a syndrome into everybody? But i can do that with booze and recurring interactions. One guy takes a swig, gets a greeting interaction he uses on everybody he meets for a couple weeks, who also get the greeting interaction and cast it on everyone they meet. At the same time theyre plied for their racial profile by the interaction, and get a random chance-based selection of abilities or, potentially, curses. Since this is all part of the same interaction set, and the abilities are permanent, a simple cannot_target_if_already_affected string is all thats necessary to prevent it going on indefinitely. Yet at the same time, i want some individuals to get none of these powers and not be eligible for round 2+, so a flat 100% chance or something of getting something totally worthless, like flipping off people they dont like, should prevent further propogation.
Does that all make sense? Do i have to worry about a memetic, ever-spreading interaction bogging the game down?
I know this wont work in adventure mode, either. Theres always that old trick of dissolving/liquifying materials like making an inorganic cloth thats available to almost everybody for clothesmaking and promptly turns to liquid, infecting them with a contact syndrome that carries a self-clean interaction for a brief while, triggering the racial interaction.