On certain creatures only a certain weapon type will work i.e. vampires, werewolves.
I can this confirm to be partially false. I was able to kill a were-something (he never transformed during the fight) with a bronze sword although he was "cut more deeply" (so said the person who sent me to kill him) by iron. Hitting him with my iron shield didn't seem to do anything out of the ordinary for what I'd expect the effect to be on a human. I recall from the devlog that blunt attacks were magnified by the damage multiplier too, but maybe that was changed later on.
I don't know if weapon materials that are not the creature's weakness are actually less effective, or just normal.
Also:
- In adventure mode, vampires can become the law-giver of a civilization. If accused of being a night creature, they'll attack you, but attacking them will
not make the civilization's other members hostile. (I was helped out by two other humans, in my case.)
- Accusing a non-night-creature does nothing as far as I can tell.
- An amusing fact, if nothing else: if paralytic/unconsciousness-causing rain occurs in a biome containing flocks of birds, they'll fall from the sky and occasionally explode on impact (depending on how high up they fly). This may be a decent way of getting meat, if the rain can be avoided. On the other hand, the dismembered bird parts might reanimate shortly after, although I'm unsure of how that works.
- Although werecreatures can probably transform in adventure mode, it's seemingly very unlikely to come across them at the right time, so they tend to be in human form when you encounter them in their lairs.
Things to check for:
- Can poison/blood rain go through grates?
- Can mist change Z-levels (e.g. going down the fortress stairs)? Does it evaporate once it goes underground, or does it stay there for a while?