How to write an OSR adventure

A beginner writes a beginner's guide

With the Appendix N Jam upon us once more, while I’m the middle of finishing the adventures for our new book, I thought I’d go through how I try to approach adventure writing.

Two maps by Daniel Locke from our new book

I’ve written a few adventures, but none of them really exemplify the advice I’ve gathered together here, and actually just writing this tempts me to revisit them all. Anyway, what follows is my attempt to bring togther my thoughts about how to put adventures together, as much as a future note-to-self as anything.

The Adventure as a Conspiracy

I’ve been thinking a lot about adventures. They’re a strange thing, sitting somewhere between a short story, a recipe and a musical score. Actually more than a musical score, they’re like a “Standard” in jazz, a set of chords and a melody that form the basis for a set of improvisation. You often hear adventures referred to as a “powderkeg”, a situation which is ready to explode once the players get involved. But in many ways it’s loser to a conspiracy board, a web of connections, in terms of relationships, space and time.

I’m talking specifically about OSR-style adventures, because those are the ones I like, ones that set out a situation rather than a linear story. The players make the story through what they do in the situation. When writing, I’m trying to build an interesting space for the players to explore and muck around in, while giving the GM the tools they need to easily run it.

Don’t prep plots

The first thing is to think up an interesting set of problems and conflicts. Or maybe just one major image:

Imagine a forest. Some people live in it. It’s their home. Some creatures live in it. It’s their home too, but they’re hungry, and the people are just there. And there are some people outside who see the forest and just see a lot of wood that they can harvest and sell upstream to the people in fancy mansions.

So how does this turn into an adventure? Just think about the things that would derive from this set of events:

• Think up a situation derived from the overall setup, like “the wizard at the edge of the forest has gone missing”.

• Define a number of Factions with goals, groups of people or creatures that want things, who will continue to act if ignored. Here we have the Forest People, the Creatures and the Loggers. All want the forest for their own purpose.

• A reason to go there Why should the players go there? Have they heard about the missing wizard who stood up to the Loggers? Are the players’ characters related to the Forest People? Have they been employed by the Loggers to clear the forest? Have they heard that the wizard had a powerful artifact?

Good reasons for the players to get involved often come in a few broad categories:

1. Devise Rumours that tempt on the player’s curiosity or even arouse a sense of righteousness. Many players react to hearing that there’s someone in need, thinking they’d like to help. “Someone’s gone missing” or “My daughter is in trouble”, anything with an emotional pull can work here. These Rumours can be something overheard in a town square or told to the players by an NPC, or in an intercepted letter. The more natural the introduction of a Rumour, the better.

2. A patron as a quest-giver is direct, and well suited to one-shots. Maybe one character is a member of a guild, or the party are emissaries from a particular area with an agenda. Or simply being paid by the Loggers to do their dirty work. Which takes us on to…

3. Treasure is the universal lure, the bait that takes players into all sorts of dangerous situations. That’s where something like the “wizard’s powerful artifact” comes in.

4. Desperation can be a powerful motivator. Maybe the party have stumbled into this forest unawares, and are being hunted by the Creatures, inevitably getting drawn into the factional disputes. Or this could even be the party’s home community, now under multiple threats.

Then once they’re involved, the idea is that you give enough information in the adventure that the players just play to discover the intricacy of the situation, and discover what happens when they intervene. As the adage goes, play to find out. There will obviously be some improvisation from the GM, but give them as much gameable material as you can, without overwhelming them with unnecessary information. Try to let lore come out through the locations, objects and NPC interactions. Let the world speak.

The map is your structure

Most OSR adventures take one or more of these forms. Sometimes it’s a dungeon in a Hexcrawl, sometimes it’s a bunch of mini-dungeons on a pointcrawl, sometimes its a wilderness adventure across a Hexmap.

• Dungeon crawl where you have a keyed map, described room by room.

• Hexcrawl where you’ll mix a regional map with points of interest and probably “empty” areas, which will be filled by occasional random encounters.

• Pointcrawl where you have a set of nodes connected by routes, which are good for wilderness or urban adventures. Or even inside big building complexes (as shown in Gradient Descent). Zedeck Siew’s A Perfect Wife is an urban horror point-crawl, and it works really well for a more social form of adventure.

Each have their merits. A dungeon crawl is great for its simplicity. The enclosed space forces decisions. Don’t forget about the “talking dungeon” though. If you have a weird lil’ guy or two, or even lean into Reaction rolls, the occupants of the dungeon can start to tell the players about the space that they’re exploring. And that extends to any of these structures.

Whatever you choose to use for your adventure, make the world do as much work as you can. Locations should imply a history, give warnings of danger, and offer real choices to the players, more than “which door should we go in”? Give clues in the environment, like a bad smell leading to the sewer, or a cold draft leading to an opening over a ravine.

Terse but poetic prose

So how do you actually write this thing? So you have a scenario in your head, maybe just an image; A castle in the sky; an ancient cursed mine; a god-like deer in a forest; whatever. Now write a paragraph to introduce the situation, just a few sentences describing what you imagine.

Make a list of all the key things you’ve just described, Locations, Factions, NPCs, Treasure. Write a short sentence for each individual element.

Make a map, just a scribble on some paper will do, and place everything on it. Now you’ve probably got enough to get started on the meat of the adventure, the place or room descriptions.

Now this is just my preference, but when reading adventures I like minimal text that has maximum flavour. Try to incorporate something visceral in the description, using touch, taste, smell and sounds to paint a picture, at the same time as being very concise. Like an OSR haiku. I’m not going to get into the whole bullet-point/prose debate here (maybe a future post?), but I’ll outline what I find easiest to use, both for prep and at the table.

For each room, hex or location, first write one to three sentences of read-aloud-able description. This should be a description of just what’s here, in the order of general mood through to actionable detail, atmosphere through to immediate attention, ending on whatever is most pertinent (or a threat).

SO:

• General description of the space (large room, clearing, canyon, prison cell), but mixed with a:

• Visceral detail (lit by the sun through stained-glass windows, a cool breeze ruffles your hair, you hear eagle’s call echo accross the canyon, a fetid bucket emits a foul stench). Follow this with:

• Actionable details (A series of bookshelves surround a central table. There is a large door to the North and a small door to the East.) End with:

• Immediate attention (A body is slumped over the table, a knife in their back). This is where you place whatever is most visible or you imagine will be of most interest to the players, from a feature that demands to be investigated (a self-playing organ, a glowing orb), through to an obvious treasure or trap. If there is something dangerous, like a creature that will attack the players, that goes last.

This order is used for a number of reasons. It creates the feeling of entering into a scene. It builds interest and curiosity. But also, as soon as you mention imminent danger, most likely a player will interrupt you (“I cast Fireball!”) or will not listen to any of the other words as they’re already thinking about how to deal with the threat.

Going back to the formatting of the text, bold every actionable element in the scene. This is useful for the GM, as it shows what they should be emphasising (and what is set-dressing), and also gives you an order for the detail that follows.

Write a bullet point for every actionable element, giving details about contents, appearance when inspected, even offer a small piece of narrative about its meaning. There can be levels to this, offering “on first inspection”, then “When studied”, following the maxim of Landmark, Hidden, Secret. The overall description handled the Landmark, Hidden is what’s revealed on inspection, but if really delved into, or if the player asks the right questions or performs the correct action (the book is opened, the glass is smashed) the Secret is revealed. Having these layers adds life to the space, and incentivises curiosity.

Also within the bullet should be any triggers (for a mechanism or trap) or reactions (what happens if it is disturbed). Maybe the body slumped on the table rears up when touched, or dissolves to dust.

Try to keep the text practical, short enough to be understood when skimming in the middle of a session. But don’t be scared to add some flavour, to make it enjoyable to read. A well-written phase can give the GM something to say at the table, saving them mental work but also adding to the atmosphere of the session.

So let’s build an example:

Room 5. The Library

You enter a large room, lit by the sun through stained-glass windows. A series of bookshelves surround a central table. There is a large door to the North and a small door to the East. A body is slumped over the table, a knife in their back.

• The bookshelves are full of books about esoteric material. Notable titles include The Cosmic Experience of One, Kybalion, The Celestine Prophecy, The Golden Dawn

  • Kybalion contains a note written in code. Once decoded, it says “meet at the spire, at dawn on the 7th day”

• The table is made of solid wood, inlaid with an intricate pattern, with several draws around the side.

  • One draw contains a love letter to Bob, signed X.

  • Another draw holds a dictaphone. It’s still recording. Once rewound, a muffled conversation can be heard between a man and a woman, then a terrible cry.

• The large door smells of boiled potatoes. It leads to Room 6, the Dining Room.

• The small door has a cold draft. It leads to a short set of stairs down to a canal jetty (Area 9).

• The body is Bob Cathertack, the person who sent the letter asking for help. The knife in his back is curved and has a jeweled hilt. There is no blood flowing from the body at all. The body is devoid of blood, all removed through two small holes in his neck.

Anyway, you get the idea. This is a dense room, with lots of information and things to investigate.

Build problems for the players

Try to give players information that they can act on: a visible switch, a suspicious draft, a corpse clutching a journal. Each small element can be a puzzle. Dangers, including traps should have some sort of warning. The fun is in working out how to avoid fiendish mechanisms, not falling into them with no warning. Fundamentally, encourage clever play by proposing puzzles without a single solution.

You should be able to imagine how something could be done, so you know you haven’t created something unsolvable, but do try to build in at least one other way to overcome the obstacle. Faced with a locked door, you can pick the lock, or break it, or break down the door, or climb through the window, or sweet-talk the caretaker into letting you in.

Design spaces in pairs

In his excellent blog, Sean McCoy recommends writing rooms in pairs, and so I will too, as it’s great advice. This instantly creates a dynamic space, where one location has a relationship to another. In one hex a dazed astronaut is walking around, in another there’s the debris of a crashed spaceship. It makes the spaces make sense and tells stories about your world. This is the best way to bring lore into your adventure, dropping breadcrumbs of information scattered across various sites. It makes a conspiracist out of each player, as they try to piece together the story.

Populate with factions and signs

The other factors that generate a living world in your adventure are Factions. Each Faction has a reason for being here, so let that seep into every location, in signs of defences against another Faction, in prisoners, stolen objects, even rumours that might be heard from non-hostile NPCs. So:

• Add rumour table entries, maybe 3-5, for each Faction, to flesh out a d12 or d20 table, to add to the general rumours. Make some true, and some misleading. I think misleading is more interesting than false. False rumours can undermine whole sessions, as players go chasing after bad information, and essentially can lead to a not fun time. Refer to this rumour table like a pick list if the players start getting into a conversation with an NPC.

• Make sure the Factions have clear wants and needs, motives that can be bargained with. Fun times can be had playing Factions against each other that have a common need.

• Build in treasure that makes sense in the location, or even better tells the story of the situation. Tolkein’s One Ring is many things to many people, a different answer to each Factions different problems, all rolled into one Ring of Invisibility.

Keep Encounters interesting

This is where encouraging the use of Reaction rolls makes games so much more dynamic, where even a Grizzly Bear could be docile, as a Goblin guard can become a font of scorn for another Faction, revealing a previously unknown secret or treasure. To add extra flavour, give creatures of NPCs their own Reaction roll tables, like Miens in Troika!.

Format the adventure for use at the table

I’ve outlined this a bit above, but here are the simple ways to make your adventure easy to run, and therefore more likely to be run by time-starved GMs.

• Write clear, evocative prose

• Bold key terms in descriptions, then make a bullet for each one

• Try to have one page per major location if possible

• Put stat blocks near where they’re needed

• Include a simple flowchart or map

Maps and Encounters

• Include a random encounter table, suitable for the system you’re writing for, or devise your own

• Have a paragraph of “what’s really going on” for the GM. That can be really helpful as an overview, and aids improvisation as the players do unexpected things and ask questions

• Have a timeline of what happens if the players do nothing. This helps the GM understand the temporal flow of the adventure, and can be a good source for events as the adventure unfolds.

Examples

So that’s all I’ve got right now. I’m sure I’ve forgotten things, but hopefully it’s helpful in some way. I love the adventure form, I think it is a great space to facilitate people telling intricate stories.

Here’s a few I recommend having a look at:

Tomb of the Serpent Kings is a good place to start, as it’s a “teaching dungeon”, that talks you through how the adventure and space is designed. It’s not formatted as I’d prefer, but I like the design logic.

Winter's Daughter paints a picture of a rich, complex fantasy world in a host of details. An adventure can imply an entire setting.

Rise of the Blood Olms really tight and resonant adventure from Yochai Gal.

Deep Carbon Observatory shows what you can do with an adventure, taking the players to a weird world, like moving through a terrifying dream.

If you haven’t written an adventure before, the Appendix N Jam is a great place to start. IsaacIsAfraid wrote one for last years Jam with citaaticat, I saw it, and ended up publishing it through Copy/Paste Coop. So who knows what you’ll end up with?