I'm GMing Pathfinder 1e this weekend and my players will be delving through a cave that was once a silver dragon's lair. I want to have a bunch of encounters planned out so that I can stretch this crawl out to the end of session, since we have a guest player who we don't want in the story for too long or too short.
Stuff they will find so far:
-Group of Frost Giants in the entrance. They don't speak common, but are pretty chill guys if a player remembers to cast Tongues.
-SO MANY SPIDERS, while escaping down a spiraling cavern. I'll have them crawling out of the walls and stuff.
-A Black Pudding. Never used one of these, and I don't think my players would know what to do immediately.
-Long underwater cave with some aberrations in it, maybe gibbering mouthers. Also a gigas clam with a huge pearl to lure in the party ninja.
-Big ending surprise - it's not a silver dragon's lair, it's a black dragon's lair, and this whole plot was him luring you to get eaten. Why is this cave so long? Because the black dragon just uses his underwater secret entrance/exit for his schemes.
Party is level 10 and there will be 5 of them, 6 with animal companion. Does anybody know any good encounters for a group like this? Doesn't need to be system specific - I'd love ideas for cool cave traps and stuff.
What about...a transition section between the dry and underwater cave sections that's an underground river (these are usually at the same level as the region's water table and will flow out the mouth of a cave into an outside stream or river or body of water at the base of cliffs or plateaus). Underground rivers flow through partially flooded tubes and large cathedral-esque caverns that can sometimes be unstable because the wet part of a cave is considered "active" in its formation. They're usually at the lowest elevation in the cave system with the totally flooded sections beneath them.
If you want to add critters, there are usually blind albino fish or salamanders that live in these rivers (dunno what the DnD equivalent is or if they're sentient, but in my head I'm imagining like a vertical village scaffolded on the walls of multiple vertically connected caverns up into the dry, stabler part of the cave).
Forgot to mention that irl people usually run boats through them.
put the giant horrible eel from Super Mario 64 in one of them underwater bits too. It's a horror dungeon now
The eel in sunshine is also creepy in its own way.
that's how you really get em. They've succeeded the perception/dexterity/seduction rolls to deal with the Mario 64 eel, come out into a larger, safe-seeming underwater space, and then bam! Mario Sunshine eel
Time to brush your teeeeeeeth