Some more research.
I created a new secret, gave all the megabeasts the secret's sphere, and generated a pocket world with a long history, lots of megabeasts, and no other secrets.
AND I GOT MEGABEAST SLABS!
It appears that once a megabeast is worshipped, it will inevitably create a slab for any secrets that belong to its spheres, provided it lives long enough. Slabs take a while to make, so worldgen might end or the megabeast might die before it can make a slab.
Megabeast worship is actually pretty straightforward. If a site is attacked by a megabeast often enough (about three times, and there may be a time limit of a century or two?), people at that site will start worshipping it. The megabeast's spheres and how many people they kill don't seem to matter. The reason why many people don't see megabeast worship occurring very often is that they tend to use worlds that are too big. The problem is that the bigger the world, the more sites there are; the more sites a megabeast has to choose from, the less likely it is to choose the same one three times.
There's no efficient solution to this, as far as I can tell. If you want megabeast worship in a large world, your best bet is to reduce the number of sites available and increase the number of megabeasts. Generating a longer history could also work in theory—the longer your history, the greater the chance of a megabeast hitting the same place enough times by pure chance—but in practice, most megabeasts are killed within a few centuries anyway. If you have extra-tough custom megabeasts, however, a longer history could work for you.
Incidentally: Regular megabeasts will travel all over the world to attack sites, but it looks like titans stay in the region they settle in--mountain titans stick to a single mountain range, for instance. This might explain why I see titans being worshipped more often than other megabeasts: they have fewer sites to choose from. With that in mind, your best bet for new secrets might be ones belonging to the nature-based spheres favoured by titans.
Also note that megabeasts that take over civilizations won't make slabs, since they won't have time for rampaging while they're ruling a civilization. They'll still write books about secrets if they have INTELLIGENT and SUPERNATURAL, though.
Oh, and from what I've seen, megabeasts won't attack civilizations ruled by other megabeasts. Professional courtesy, I guess. No rampages means no worship, means no slabs. Luckily they don't have this problem if the rulers are semimegas or regular creatures.
One more thing: Megabeasts that take over civilizations (any creatures, really) have a much lower life expectancy than ones who stay in the wild. Wars are dangerous.
The NO_AGING tag, it turns out, carries an enormous amount of weight. A lot of the things that night creatures do in worldgen are derived solely from this one token.
Creatures with NO_AGING:
Don't age, duh.
Can arouse suspicion for appearing not to age. Their response depends on a few factors:
- If they're the ruler (monarch, law-giver, etc) of their civilization, they impose a series of oppressive edicts upon the population, lifting them some time later.
- If they have a cult (see below), they'll challenge the ruler of their civilization. The winner becomes the new ruler, and the loser flees.
- If neither is the case, they'll flee to a different site. This is usually a town or hamlet, but sometimes (if they've already been kicked out of every town in their civ, perhaps?) they'll hole up in the sewers or a lair.
(Note that regular people never do the challenge thing, only unaging ones. Well, that's not quite true. NPC adventurers from enemy civs will occasionally confront unaging and megabeast rulers. I don't know if they go after ordinary rulers too, or just monstrous ones.)
Can start cults. I don't think cult worship is really worship, since I've never seen a named character join a cult or a cult leader create a slab. Cults are probably closer to bandit groups than actual religions. On the other hand, I've also never seen a megabeast ruler start a cult after suffering a 'curse' of unaging. It's possible that this is because they already
have worshippers of a sort, through the deity they're impersonating.
Are potentially night creatures! I mentioned earlier that the unaging can sometimes end up in a sewer or a lair; once this happens, they count as night creatures and will go on rampages! As far as I know, this is the only way to get a hostile night creature to live in the sewers. (That said, I still have a lot of research to do on transformation syndromes.) Note that the unaging will lose their cultists if they go this route.
(I'm not certain, but I think subterranean animal people (the kind who live naturally in sewers) are more prone to becoming night creatures this way than regular civilized folk. Perhaps because they aren't really part of their civilizations, so they don't have any towns they can flee to?)
Rampages are kinda interesting. Any night creature (besides bogeymen), mega- or semi-megabeast, or creature with LARGE_PREDATOR is capable of rampaging. (EDIT: Unless they're civilized creatures, in which case only being a night creature will do it.) A basic rampage involves attacking a bunch of people at a site.
If the creature has CARNIVORE, it'll also devour animals and people.
If it has a CURIOUSBEAST_ tag, it'll often steal things instead of attacking.
There may be other tags that affect rampages... I'll let you know if I discover more.
Right, I said I would talk about secrets and curses. Pretty simple, really: they're completely identical except in how they're acquired. A curse with an animate effect will let you build towers just like a necromancer, but you won't be able to take on apprentices or write about it. An interaction that's both a curse and a secret can be acquired either way, and passed on however you like.
A side note: While looking through the string dump, I found an interesting string: "became obsessed with an inscrutable goal". This looks like some kind of default secret goal, but removing the IS_SECRET_GOAL token from an interaction just made the secret not show up. An IS_SECRET_GOAL value of NONE gave an error. Anybody have any idea how I could get that phrase to show up? It's a lot more useful than "became obsessed with his own mortality and sought to extend his life by any means".
That's all for now, but there's more to come. Next, I intend to explore animation and transformation interactions, as well as syndrome transmission via attack and body materials.
Also, if you haven't already, you should check out Spiderking50's
Rise of the False Gods, which will be using a lot of the techniques discovered in this thread.