Ok guys, I'm planning a post apocalyptic Tokyo campaign, where the world has changed to the point players can go into a cave that is really an abandoned hotel, or stumble into a dilapidated "Shibuya Scramble" in a Dessert.
The thing is, I'm designing some dungeong and looking at older Monster Manuals from D&D and my Pathfinder manuals, and tho there are lots of interesting monsters I can imagine as an encounter inside a dungeon, I don't see how they can fit in an environment, since I'm not really fond of using Goblins and Orcs as dungeon delvers, and most of the creatures I'm using for this game are either ghostly, aberrations or extraplanar creatures (tho I don't discard the sentient, natural ones).
Like, an Attic Dweller (Pathfinder Manual 2) is the ghost of a kid made up of china dolls and dead animals creating well, an ungodly spawn with the head of Barbie and the body of a diseased chihuahua that attracts young adventurers (teens and kids) into going where they are, only to have their soul drained by the group of 3 to 8 bastards later.
Or, Cave Fishers, we all know those guys. They get together, use their tongues to fish,and attack every other creature while they are hunting because well, they just dislike other creatures while they eat, as every other big bad peanut brained arthtopod does, everyone wants to kill them.
The thing is, I'm attracted to encounters that have a creepy, bizarre or plain gross factor. Rot Grub Swarms, Remorhaz, Poltergeists, Golems, etc. But most of these creatures have no reason to live together, and I'm wondering how I can populate dungeons with creatures that want to eat the players alive, take their souls, etc. But I'm just plain bad at populating dungeons.
I also place good creatures for social encounters, like Archons and some traders, but they are few and far between since my players must feel LONELY on an inhabited and hostile Tokyo. The game's not horror per se, but I don't want it to feel like a normal epic fantasy campaign.
You should probably think of why the world is in that condition. Monsters must have a reason to be there, you said that yourself, so you have to go back to the root of the campaign, the "theme".
If your Tokyo is a post-apocalyptic spectral mess, maybe it's because scientists experimented with a weird mutagen. Or, maybe, they developed a serum that was meant to make people better (sorta like Dr. Jekyll & mr. Hyde) and the serum actually enhanced their nature, transforming evil people into monsters and good people into paragons of virtue. And maybe neutral creatures are stuck in their human form, or they change into mindless oozes and such... You see, there's always a way to make it fit. I suggest you take a look at the wide variety of anime, movies and manga set in Tokyo and featuring monsters (Gantz and Akira are just two, but there's a lot more).
Emanuele_Galletto wrote:
Well, you could basically assign each monster a "category": mastermind, henchman, servant, animal. This way you can have some sort of hierarchy. For instance, the mutated rat-men worship war and disease and employ swarms of rats, oozes and other sewer-connected creatures: they hate snake-men (since snakes eat mice) and ride giant bats into battle. You know, find a theme that fits more than one creature and elaborate on that. If you want, maybe write the critters you'd love to use here in this thread; and we'll see what we can do 
Here's a resource to check out: Prep Tips.
The first three of the tips have some links to dungeon design and the articles they link to probably have a number of other links that would be good to read as well.
One of my favorite blogs is currently going over dungeon design as well: Deeper in the Game.
Good stuff, Iserith!
Aldath wrote:
Japan has a crazy amount of ghost/monster lore, already.
Id consider mining that first, to keep a cultural feel.
Second, on dungeon design, pick your dungeon, ask who built it and what it's for. Create a layout, conceptually (a hospital might have a lobby, ambulance bay, recovery rooms, surgery theatre & morgue).
Third, pick the theme you want to achieve. Horror, terror, divinity, nature, human, mechanical, whatever. And populate your dungeon with monsters or hazards that reinforce your theme.
Last, design your encounters: social, exploration, & combat, (all according to your preferred style).
There won't be a way to systematically populate every dungeon in a single stroke. At this level, design requires individual site-based effort. And good design requires thought and planning.