How to approach randomization in detailed established settings

Playing in existing settings can be a ton of fun, but many of them have been developed for several decades, and it might feel like there isn't any room for the kind of random generation that is so fundamental to solo play. Here are some tips and methods for how you can approach these settings.

Preface

My main joy in RPGs (as a GM) was always to see how the player characters interact with the world around them. As a solo player, I tend to gravitate to a similar playstyle. There are many settings that I'd love to explore through play, but it was always intimidating to be presented with so much existing lore. After trying out different approaches, I finally sat down and defined several methods that worked for me.

RPG sourcebooks always ride the fine line between providing just enough details to inspire adventure hooks, while not overloading the area with too many details that would restrict creative freedom. Self-contained books and newer settings usually do a pretty good job with that but what about settings like Warhammer Fantasy's Old World, D&D's The Forgotten Realms, Pathfinder's Golarion, and all the others?

Published adventures, campaigns, and supplements from countless authors over many years have filled these settings to the brim with wonderful detail and information. This can be a gift and a curse for solo play.

How am I supposed to be surprised by random tables if everything is already pretty much defined?

The Easiest Method aka Evading the Problem

The Method: Ignore anything that stands in the way of your narrative.
The Good: Very easy and quick to do. The less knowledge of the setting you have, the better.
The Bad: It might not really feel like you're playing in the 'official' setting, and it can easily devolve into homebrew territory.

As almost every RPG book likes to remind us: It's your game, so make it your own! Focus on the things you find interesting and ignore the rest.

Who cares if some adventure says that the dungeon over there is filled with skeletons or partially flooded? Just ignore that adventure and randomize the dungeon with your favorite generator or supplement.

A large city that has entire sourcebooks dedicated to it where every individual building is described? Ignore it and only adopt the overarching feel of the city. It doesn't matter if that one butcher's shop is suddenly turned into a museum for the purpose of your adventure.

Focus on self-contained or small locations

The Method: Keep your story localized so it won't step on any established lore.
The Good: Surprisingly flexible and easy to apply. Barely any risk of lore conflicts.
The Bad: Restrictive by nature. Doesn't work with every type of adventure.

Dungeons are your friend. Any enclosed space like a mansion, cave, castle, warehouse, spaceship, underwater station, sewers, prison, etc. works perfectly because you can focus your randomization on that specific location.

Every setting has space for a single building or a cave entrance somewhere. Find a spot that you like and carve out your own little corner. Apply the general theme of the area and try to stay true to the surroundings. Anything else, you can leave to the dice.

Look for underutilized areas

The Method: Focus on the locations that have the least detail.

The Good: Allows flexible randomization while still staying true to the established setting.

The Bad: Inherently limits you to areas that aren't the focus of the setting.

Even the most fleshed-out setting has a corner somewhere that is mostly just a name on a map or a short paragraph roughly describing the area. Use that as the foundation of your adventure. Usually good for hexcrawls and other exploration campaigns.

Only use setting appropriate random tables

The Method: Create custom random tables that only have content appropriate to the setting.
The Good: Allows flexible gameplay across the entire setting.
The Bad: It takes a lot of time and effort to create or replace oracles and random tables.

This is a method I'd only recommend if you plan on playing several campaigns within the same setting. Custom random tables can make your sessions incredibly immersive, but it's usually not worth it for a quick adventure here and there.

It works best for worlds that have very specific environments with unusual inhabitants. The farther the setting moves away from generic tropes, the more rewarding you'll find it to make your own custom random tables.

You can also use prewritten adventures for this. Read through them and take note of the themes and encounters. Use them to make random tables that would allow similar adventures to take place.

Don't use random tables at all

The Method: Replace random tables with the information presented in the source books.
The Good: Immersive method of exploring the setting. Easily creates believable adventures.
The Bad: Quite predictable depending on the environment of your campaign.

Any time you're unsure about something in the world, you look up the existing setting information and pick the most obvious answer. Sourcebooks usually describe the dominant inhabitants, flora, fauna, and other noteworthy cornerstones of each area of the setting.

Example: You find a cave in a forest. The sourcebook describes the forest as bandit infested and home to a lot of wolves. You flip a coin to decide between 'bandit hideout' and 'wolf den'.

You could also decide to randomly determine an answer by rolling for a page number (especially fun with bestiaries) and pick something from that page.

Closing Thoughts

As you can hopefully see now, randomizing content in an established setting isn't as difficult as it might appear at first glance. It's very intimidating to dip your toes in the wealth of information that is available out there, but I highly recommend giving it a shot. Try out the different methods I explained above and figure out what works best for you.