I just learned that Ghosts of Saltmarsh apparently has a section called "Of Ships and the Sea", presumably developed from the Unearthed Arcana of the same name. I generally don't buy adventure books unless I'm planning to run that actual adventure — but it occurs to me that these rules might come in handy should my players in a different game decide to venture into the ocean. I learned about this because I happened across a review:
But it also has just as much info on how to navigate the sea according to 5e rules, the dangers that await, weather conditions and health issues, the creatures that inhabit it, and all the mechanics in-between. If you’re a DM and you want to create an adventure in the ocean, D&D just gave you every tool you’ll ever need to make it happen on your own terms. That’s one hell of an addition to the game that a lot of people who deal with seaside adventures will gladly take advantage of.
This seems pretty significant — in previous editions this might have been a section of the Dungeon Master's Guide, or a DMG II, or a book specifically for adventuring in a that type of environment. This time around, it seems like they're tying the publishing of this kind of rules expansion to adventure hardcovers.
So, this has me wondering. What other adventures published for 5E by WotC have significant rule sections like this? I don't mean lists of magic items, monsters, or character options (such as races, subclasses, and spells), but rather specific rules that might be useful in any campaign.
Or, perhaps, what's an easy way to find all such possible rules without looking through every published adventure, or just knowing?