Designing adventures is one of the essential skills a GM needs to pick up. There’s no one right way to do this. The most important criteria is that you’re able to run games on a timetable that your group is happy with, and everyone is having a good time in the process. So you want a process that is time efficient, but also is infused with a level of creativity that you’ll be happy about what you’re doing. The following is what works for me.

Step 0: Create Brain Dump File

Writing might require discipline, but creativity usually happens in fits & starts. Have somewhere where you store all those stray thoughts. As you populate your adventure with more stuff, you can always refer back to the brain dump to see if anything can be slotted in. Another fun thing to do is pick three random things in your adventure and/or brain dump file, and declare that they are related somehow. It’s now up to you to come up with some sort of explanation for this relation. If you come up with something cool, include it!

You can also jot down any inspiration you get from things you read, games you play, evil people you read about in the news, places you’ve travelled to, etc. That being said, limit yourself to stuff that works in the context of a tabletop game. A movie might do really cool stuff with out-of-frame sounds, but that’s a cool thing you get to do within the context of film, not most other mediums. Similarly, a lot of people were inspired by Elden Ring, but not all of it translates.

Step 1: Decide on a Theme/Premise

We want to get this out of the way before we tackle anything else. Deciding on the theme/premise means defining what the adventure is about. This definition should have a couple of important properties:

  • It succinctly communicates what the adventure is about
  • It is distinct and evocative
  • It clearly delineates what is appropriate content for the dungeon

Examples of strong themes/premises:

  • A burning library
  • An alchemist’s lab seized by brigands using the equipment for brewing booze
  • Being aboard an orc spaceship flying into the sun
  • Escaping a sinking prison boat
  • A natural history museum overrun with witches

Note that a key feature of the examples given is an implicit location. This might not be the case depending on the type of RPGs you play, but if location based exploration is your style of tabletop game, then you can consider that an essential feature of your theme as well.

Step 2: Define Factions

Presumably there are NPCs in your adventure. A faction is any grouping of NPCs, including a solitary NPC! Factions work together towards a common goal. If the faction has more than one type of NPC, there will be a leader. This includes factions with anarcho-communist politics, even among flat social systems implicit power structures form even if they are not formally defined. This doesn’t need to be like a video game where the leader has boss stats and abilities, they can share identical statblocks with others if that makes sense, but interactions with the leader of a faction should have an outsized influence on that faction’s attitude towards the party.

Personally I think a good adventure should have at least two factions, ideally more. Not all of them should be innately hostile. But having them be of varying degrees of power and malice is a good idea.

Once you have your factions defined, you can include what their relationships are to each other. This doesn’t have to be in depth, a lot of times it is as simple as Faction B is Faction A’s prey.

All factions should have goals and desires. Goals are what the faction is working towards, and desires are things that might make the faction be more inclined to help or ally with the party. Factions should also have a good reason for being at the adventure site.

If you want to add additional texture, you can also define some NPCs that have goals/desires that might make them at odds with, or at least somewhat distinct from the group. Not something that is regularly worth doing, but is a nice thing to include every once in awhile.

One final note on factions is it is really easy to go overboard with details about them. Resist that temptation! You need to be focused on the needs of the table. Really they just need some basic motivations and standard NPC types. If they are long term fixtures of your campaign you can add some Forged in the Dark style clocks to track their progress from session to session.

Step 3: Define Spaces

For your classic dungeon, these are going to be your rooms, but could just as easily be a node in a point crawl, etc. I usually start out by listing a bunch of names of spaces that fit with the theme. I don’t worry about how these spaces are connected to each other yet. By listing out the number of spaces I’m also doing a reality check on the scope of the adventure I’m designing.

Spaces might have monsters, traps, and/or treasures. But wait, we’re actually getting ahead of ourselves here! A space should have a purpose, which means that there is something you should be able to do in this space that you wouldn’t be able to do in a different space. We want spaces that players can interact with above all else! Interactions don’t have to be complicated. They can be mechanisms that unlock a passage elsewhere, empty bottles you can throw, things you can pry off the wall, or cabinets, barrels, etc. to store objects. Interactions answer the question “what can the players do here?” Ideally, that includes things you didn’t anticipate.

Once you understand the purpose of the spaces and their systems of interaction, you can consider their other aspects. This is where keying comes in. Keying is a huge topic, and there is so much that has been written about it so I won’t go into great detail. To me, a good key quickly establishes important information to the reader (e.g. the GM) who then imparts the knowable information to the players, and does all this while imparting the relevant flavor and tone of the adventure. Putting stuff in bold that has even more detail if the players so inquire is a tried and true technique for writing keys.

Step 4: Populate the Spaces

Okay, you now have some defined spaces, and you know some basics about what the spaces are about and what you can do in them. Now is the time to fill them with NPCs, treasure, and traps/hazards/puzzles. Since you know what the purpose of the room is for, you can now think of how it should be appropriately populated.

Your NPCs should always have a name, no matter how minor they are. If you don’t include a name your players are guaranteed to ask about their name, and you will freeze up in the moment when that happens. Other than that I give NPCs an attitude, occupation, and what they are probably doing. If they need other details then include those, but this is usually enough for me to work with as a GM.

I don’t have any especially helpful advice for stocking treasure. Maybe that is something to think harder on and write up for a future blog post. Treasure should have a good description attached to it. If a description of a piece of treasure is so enticing that your players take stupid risks to try and acquire it, you’ve done your job.

When I say traps, I use that word mostly because that is the convention of how we talk about RPGs, but I think a better word and way to think about traps is describing them as “complications”. In other words, literally anything that creates some sort of complication for the players. Traps and puzzles fit the bill, but it could also be things like bad weather or two NPCs in the middle of an argument. This is another big topic though, and probably worthy of another blog post all on its own, and it has been written about extensively all over the OSR blogosphere.

Step 5: Connect the Spaces

I typically only start connecting the spaces now. The exception might be for an adventure like While the Alchemist is Away where I was actively collaborating with the artist. In that case I had the sketch of a map illustration to work with, and so I could let my imagination run wild on how the rooms worked based on this sketch. But typically a map I draw isn’t going to lead to any inspiration, so instead the mapping will be inspired by the keyed writing for the spaces. I suspect the order that makes sense for you will have more to do with whether you are more of a visual or a verbal kind of person. Either way, this is the point where we are logically organizing our physical space, what connects to what, with special attention to entrances/exits, and connections that aren’t a basic path (secret passages, spaces divided by a chasm, trap doors that lead to other floors, etc.) I’m also contractually obligated to mention that you should be Jaquaysing your dungeon. I tend to lean more towards designing spaces with versimillitude than a perfectly Jaquaysed space, but you know, if you see an opportunity to include an extra loop and what not, go for it.

Step 6: The Extra Bits

Your adventure probably has some special details about it that might require some extra rules or procedures that you’ll need to include. You’ll also want to create a random encounter table, and any other systems that will make your adventure tick. This is also when I work on my adventure hooks, which, as I’ve previously established, is a useful exercise for evaluating how multifaceted your adventure is.

If your factions are well coordinated you can include some order of operations for them if they come in conflict with the players.

Assuming your adventure site has some sort of end state it is useful to game that out a bit without being overly prescriptive. I like the approach Joel Hines takes his adventures include a section that details what happens if the players do nothing. Stated another way, you now have a list of things that the players have the potential to interfere with!

If the adventure site is part of a hex crawl where the idea is that this might be a place the players return, you can also includes some minimal notes about what will change over time, but this is incredibly optional and it’s never worth putting in extra work over stuff the players might do.

Final Step: Iterate!

It’s worth doing at least one pass where you go through and make adjustments to things now that you have the whole adventure in your mind. If this is something you’re planning on publishing you’ll also want to also playtest it, ideally several times with different groups, and make additional changes based on what didn’t work, was too confusing or challenging, or just anything else you’d like to punch up.