Running a City, the Ultimate Sandbox

The ultimate test of a GM’s skill seems to be the city. It's packed tight, full of possibilities, more than you can possibly see at first glance, and constantly changing. In order for a GM to run a city well, they need the right tools and the right prep. In this article, I break down how I set myself up for success at the table, so I can spend my energy in session focused on making the city feel alive.

Like any other sandbox style, our goal is to prep as little as necessary while giving ourselves enough tools to improvise on the fly without having to make it up on the spot. But how do we do that? Well, I like to start by borrowing as much as I can from pre-published materials. That’s not to say that you have to, but building a city from the ground up takes a ton of time. Personally, I think that time is better spent recontextualizing something and making it my own. For this walkthrough, I am going to use the Meridia, “The City of Masks,” from Shadowdark's Cursed Scroll #6 as an example (Read my review here).  

The Prep List

So let’s start by defining all the tools you will need to run a city well. I would consider this the bare minimum for a large city. For smaller towns and hamlets, you will naturally have fewer of these things. You may even choose to ignore one or two of them entirely. For example, a small city in a wasteland may have only 1 law and no factions. I’m going to focus on large cities because they are the most challenging.

• Locations
  • Popular Locations (Known to everyone)
  • General Locations (Known to locals, broken down by ward)
  • Hidden Locations (broken down by ward)
• Local customs
  • Government
  • Laws
  • Holidays & events
• Factions
• NPCs
• Rumors
• Random encounters

Locations

This one seems obvious, but what I think might not be so obvious is adding locations to your city that aren’t well known, so that you can reward exploration. So I like to break locations down into three categories: 

Popular Locations (40-50):
Think of these like tourist destinations; they are well known to the average person. These are the locations you are going to place on the player’s map (If you give them one). They are going to be heavily trafficked and full of common items and sights. In a larger city, you can assume that there are 40-50 of these spread across it. If you are building from a module, these locations will most likely already be included in the book or on the map.

General Locations (3-8 per ward):
You can think of these as the spots the locals frequent. While wandering the streets, the characters may be given the locations of these spots by talking to NPCs, especially within that ward. These locations will carry rarer items and cater to a local audience more directly. 

Hidden Locations (2-4 per ward):
These are going to be interesting but more niche locations. If it’s a place like a tavern, maybe it’s a private, membership-based one. Or maybe the location is a shop that caters specifically to bards' needs. The characters will primarily learn about these locations through mission-driven NPCs and by deliberately spending time searching the ward (more on this below).

So, how do we organize the locations?

I like to add a single page or spread per ward to my GM Binder. It starts with a thumbnail of the ward, and is followed by a list of locations with highly abbreviated descriptions and a page number if referencing a module. It looks like this:

For example, this is how I would abbreviate The Golden Marmot from page 57. The original entry reads as follows: 

The finest inn in the city with a gold statue of a fat marmot in the lobby. Important diplomats and merchants enjoy the inn's superb cuisine and lavish suites staffed by a personal butler and 4 private guards (50 gp a night). The capable Chief Concierge, Emule Virdan, doesn't permit riffraff and knows all their tricks. Entry requires 8+ renown.

Abbreviated Version:
21. The Golden Marmot. Concierge: Emule Virdan, only admits the wealthy. 4 private guards, butler, diplomats, merchants, and superb cuisine. Finest inn in the city, 50gp/night. [57]

Formatting Breakdown:
Map location number and name. Main NPCs. What’s Inside. Other Notes. [page number]

Then I separate the popular locations from the general and hidden locations with a horizontal rule and list them with a two-letter ward abbreviation and number. So the "Montmar Castle District” would be abbreviated as MC#. This way, I can add the location number to the map and roll against them when the characters are searching the ward (more on that below). 

Example Hidden Location:
MC6. The Golden Reed. Shopkeep: Finnigan Reed, friendly halfling. Magical instruments and fine instruments. See magic instrument list. [ ]

The only difference with this formatting is that I replace the page number with a box I can tick when the characters discover the location. Doing this makes sure I don’t randomly roll it again when they are exploring the ward in the future.

So, how do players find the new locations?

Well, I’ve taken a page out of Ben L.’s book and follow the procedure he details in his article “Rules for Citycrawling.” I take a die equal to the number of unknown general and hidden locations inside the ward (thanks DCC funky dice!) and roll it to simulate them wandering around until they find a new place. During this time, I will also make a random encounter check. If no encounter occurs, I will describe the ward and their journey as they happen upon this new location. It's that simple. 

Local Customs

Customs help establish the differences between the cities the characters visit. They are a useful tool for worldbuilding and a great way to establish a city’s tone.

Government

Every city, regardless of size, is managed in some way. Consider how the government is structured and who is in charge. 

Laws

Most large cities will also have a guard to uphold the peace and a unique set of laws. I suggest keeping this list on the shorter side, mostly guided by common sense for simplicity, but adding a few unique restrictions can add to the flavor of your city. 

Holidays & Events

If you plan to track time or stay in the city for a long time, holidays and events can be a fun way to make the city feel unique. A public holiday can be a great distraction for a heist adventure or a great way to introduce the city's rulers in a public ceremony. 

Factions

These are large groups that have shared goals. These goals will naturally conflict with those of other factions. It is this conflict that allows you to create interesting rumors and adventures that can shake up the balance of power within the city. This is why factions, more than any other element of our prep, afford the opportunity for the characters to affect the world around them. Their actions are like placing a finger on a scale, tipping the balance of power between the factions. But it is important to think of this push-and-pull between the factions as playing out at all times, with or without the characters’ intervention.  

So, how do factions compete with one another?

The most straightforward way I've found to run factions is Mausritter's faction procedures. They have managed to fit a detailed example and a full set of rules in a single 8.5” x 11” spread, including art. I’ll paraphrase here, but the rules are free and it's an amazing game, so download them, you won’t regret it!

Pages 30-31, detailing faction play in Mausritter

Simply put, each faction’s goals are given 2-5 “progress” steps that need to be filled to be considered complete. In between sessions, you roll a d6 and factor in competing faction goals and resources, and if the result is greater than 4, the faction will progress at least 1 step toward its goal. The players’ interaction can also add or subtract 1-3 progress steps based on the scale of their efforts. As the factions achieve their goals, determine how that would affect the city and be prepared to communicate it in future sessions. 

As an example, you may have a cult that has a plot to infiltrate the city’s most wealthy social circles. After achieving their goal, it becomes fashionable for nobles to wear sashes in the same color as the cultists’ robes. Indicating that these people are now faithful to the cultists’ ideals.

What if the characters want to join a faction?

Shameless plug: I am kickstarting a zine series designed to aid faction play in city campaigns. The League of Dark Few saga details everything you need to run a guild of “influence brokers” who silently help the nobles pull the strings of society. It starts with a brutal initiation ceremony (a level 0 gauntlet) and helps you build a home for the characters inside the chaos of the city. Check it out and follow on Kickstarter.

Follow the project and download the free Level 1 adventure “The Crypt of the Forgotten Duke” when it launches on February 10th.

NPCs

You will generally have two types of NPCs that you will need while running your city campaign. The first is recurring NPCs tied to factions or adventures, and the other is a list or table for generating random NPCs when the characters are exploring. I suggest keeping a list of recurring NPCs, with brief notes on their wants, quirks, and mannerisms, so you can quickly flip to them when they appear. If you need help generating new NPCs, I suggest you check out Murkmail’s “The only 12 NPCs you need.” It's a great shorthand method to create NPCs with depth. 

For your quick reference NPC table, I suggest you follow the excellent formatting presented in Cursed Scroll #6. Take entry 40 from the d40 table as an example:

40: Cindri Quentin, young woman, skilled blacksmith, makes rare wavy daggers, likes birds

You have a name and enough detail to come up with a description of their appearance and a quirky behavior that sparks interaction ideas in the moment. The perfect level of detail to be interesting and memorable without taking a ton of time to grasp. Adapt this table for your game, or make one like it.

Rumors

Rumors are the glue that holds everything together. They hint at new locations, reveal the agendas of factions and NPCs, and send the characters in search of gold and glory. Start with a list of roughly 10 or so rumors that you edit and replace as the characters start to interact with the world and build their story. I like to start with a broad list that points in all sorts of directions and then replace used rumors between sessions with deeper information relevant to the threads that have already pulled. I balance these with rumors of new adventures, so the city always feels alive and full of new opportunities. 

Some things I like to do with rumors:

• Point to new hidden locations, maybe ones that can’t be found via searching, to reward interacting with NPCs.
• Use them in my random encounters, maybe it’s a mystic offering a fortune, or a street urchin who claims she saw people carrying gold into an abandoned storefront at night.
• Localize them to a specific ward; maybe the slums reveal more info about the local thieves’ guild.
• Don’t be afraid to select a rumor when it makes sense. Don’t get trapped making a random roll when picking on might be more satisfying, use the tool however it helps you run the game. 
  

Random Encounters

Sure, most GMs know what a random encounter is. However, I think it’s important to handle them differently in the city. While random encounters in the wilderness and a dungeon typically represent a threat, in the city, I think it’s more important that they are used to make it feel alive. That means many encounters that may not be hostile. Maybe it’s just an interaction with a beggar while visiting the slums, or someone barking about a local cult outside of a church. Random encounters become a tool for revealing more about the city, its factions, its people, and its locations. They are also a great opportunity to reveal new rumors to the PCs. I write them out as a simple list, formatted like this:

1. An old man holding a sign that reads “the end is nigh” warns people that spirits are spilling from a gate to the hells inside the old temple [MC3 – ruined temple].

There is a temptation to make a huge list of random encounters and roll against them for the whole campaign. Like rumors, it's better to make a list of 10 or so, and then edit and replace them every couple of sessions as they get used. This allows the GM to adapt them and introduce new ideas as the story emerges through play. 

Remember to roll reactions and distances as well; it’s easy to forget, but it adds more context and depth to your random encounters. I like to use these simple ones:

Distance (d6)

Reaction (2d6 + Charisma or Personality mod)

Taking It To the Table

With all these tools easily accessible, you are ready to run your city adventure. Start small where you can, focusing on a ward or two at first, and you will get the hang of it in no time. 

One last tip: consider creating a custom GM screen for your city that includes the reaction tables, the random NPC list, random encounters, and the city map, as you will reference these often.