Before the D&D campaign begins, it would help if I knew what the setting looked like. Technically, I have skipped everything but naming the starting town, but we can put in a tiny bit of work. The players might ask questions about this stuff and it could matter.
Prep Work
I’m busy, I don’t have time to design every NPC, town, world map, etc. So I only want to build as much as I think I need. Using an existing campaign setting might be easier, but that’s never been my style.
Deities
Some of the classes specifically tie into religion. I could make some stuff up or borrow from mythology. Heck, use the gods in the Player’s Handbook and give them new names. In a fantasy setting, religion is a daily part of people’s lives. Zealots should be popping up now and then, objecting to what the players are doing. Or a church might need help.
Town
Plan to start in a small town, you can go bigger if you want, but then you need a bigger map. I’d use a random town generator and change the names I don’t like. Save a copy, print it out, call it good. You’ll need to know who and where for the town leadership, a few stores to buy supplies, and a temple or two (Religion!).
NPC Roles to fill:
Mayor
Sheriff
Leader of each church
Weapons shop owner
Armor shop owner
General store owner
Tavern/inn keeper
Guild masters (if any)
You won’t need to make another town until the game scale brings it up. Either, because something happened, and it’s news or the party needs to deliver something.
Regional Map
Once you know there’s a town, what’s around it? Towns appear at places conducive to trade. River or road crossings, terrain transitions (like ocean to river), etc. Water is always important to survival so put that on the map.
Countries
Politics is a source of problems, so it’s a good idea to know who the neighbors are and who likes who. You might skip this step, but it’s going to be weird when you mention a kingdom the players never heard of that’s been at war with us for the last three years. Countries don’t have to be huge. They might even be city-states, which is a big city and the surrounding land to support it.
NPC Roles to fill:
Leader (king, regent, whatever)
Leader’s spouse
2nd in command
Advisor(s)
Opposition Leader (somebody objects to the king, carefully perhaps)
Notable NPCs
The first (or second) thing paramedics ask somebody who’s been knocked out is to name the President. The PCs and NPCs should know the equivalent. People in power are the original celebrities, so that’s where we should start. Rival and allied kingdoms are also names to know. A given NPC might not know every name, but they can’t know any of them if you don’t make it up now.
For the Town and Countries section, I listed some roles to fill. Unless the players take to stabbing folks, you just need a name and a description. You can add details and specific later if you think you’re going to need it.
Go to Town
Since the game is going to start at this town, we will need more than a name. The players are going to tromp around and meet NPCs.
Here’s what a small town might have (which supports your D&D adventuring needs):
church(es): Several of the deities have presences, and people go to all of them
Shops (weapons, armor, magic, general good)
jail/barracks
Blacksmithy
Mayor’s house
Town hall/square
Houses for folks who don’t own businesses
Tavern
Inn/flop house (not always the same as the tavern)
Warehousing (in a port)
Back in the day, business owners lived on premise, usually above the shop. A wealthier business might afford a separate, nice house. But for basic shops, owners stayed close to the goods.
This means that in a very small town, you don’t need a lot of buildings. The actual houses either belong to wealthy merchants or people who work for the various businesses. Few if any people in a town don’t have a job, thus, you can tie the number of homes to the number of main buildings. Ten main buildings, ten main houses, give or take. Nice and easy.
Generators
I’ve been using online tools to whip up content like this for decades. Things have changed, old sites have died, but there’s still people making free stuff to make stuff. Note, most or all of these tools are not “AI” based, and in the context of making stuff for your private D&D game, we’re just not going to worry about it.
Town/City Maps
Regional/Country/World Maps
Location Generation
Names
Random Quests
Make It So
There’s tons of prep work you could do. Or skip. I’ve started campaigns with less. However, if you don’t put in any world building, the lack will show up in the game. Don’t overdo it, but a small amount of work up front will help season the stew.