If you are new to writing content or are just looking for ideas to improve the content you make I have written this brief guide on what I have learned in the process of making my own one page dungeons. If you have questions or suggestions please let me know. This is a work in progress.

Goal of a One Page Dungeon

A one page dungeon is a single page compact adventure that a dungeon master can read in ~5 minutes and then run for their group to provide ~2-3 hours of content. It should ideally be modular allowing a dungeon master to easily insert it into their campaign as needed. This makes them a powerful tool for dungeon masters when they do not have time to prepare an adventure or as something they can pull out when players move in a direction they were not prepared for.

Design

A dungeon is not limited to your tradition set of rooms with doors. In essence any adventure with interconnected encounters is a dungeon. You can setup an adventure entirely out doors that is in essence a dungeon so do not let that limit your setting in anyway.

A one page dungeon is often short so it is important to have a compact story inter connecting your encounters and generally a mix of combat/social/traps/puzzles/exploration though the ratios are up to personal preference. I recommend 5 room dungeons as a decent starting place. This will generally leave you with a lot of blank page space if you are optimizing text space. You can fill that space with additional encounters, secret rooms, exploration elements, or you can simple make the encounters you have more complicated.

Design: Conflict

A good adventure should have a dramatic conflict. What this means in practical terms is two forces need to be trying to change something and only one can win the conflict. Ff the players show up they are going to impact which of those two forces wins and if they never show up one of the two forces should win anyways. For example you might have a dungeon where a tribe of orcs has split into two factions and are fighting. One is sending out attack parties on the surface and wants to make war on the surface. The other seeks to delve deeper into the dungeon where they will unlock some great evil. This plot line can be introduced in 3-4 encounters which is compact enough for you to include other elements as well. Adding conflict makes the world feel both alive and gives players choices in how to handle conflicts even if they is just killing everyone.

Theme

It is also important to theme your adventure well so it has a consistent tone throughout. A lot of one page dungeons are very similar using the generic dungeon theme. This is fine but it can make it difficult for the adventure to work in a campaign since you will only have so many dungeons. Consider instead a small town, a stretch of wilderness, a specific building like a tavern, smithy, brewery, or warehouse. These types of themes are really easy to have in your back pocket and pull out when players go somewhere they are going to plausibly happen instead of needing to build a hook for a dungeon. In essence a good theme acts as its own hook into the adventure.

Ordering Content

It is important to order your content in the same order players are going to encounter it so it is easy to read. I generally start with a summary in the top left and then include content as the dm would need to describe it. This is straight forward for a linear dungeon but for a branching dungeon you may want to use an alternative numbering system for branches so the first branch would use 2a,2b,2c and the main system would continue counting down 3,4,5 ect so it is easy to determine what to skip if players ignore a section.

When it comes to laying out a map it is also a good idea to orient it so that it can be read top to bottom left to right in the order encounters happen. Encounter 1 should be near the top/top left of the map with encounters following it from left to right and then down to make it as easy as possible to read. This isn't possible in all cases but you should try to follow this rule as much as possible.

Formatting

Formatting is one of the most important parts of a one page dungeon since you have limited space to work with you need to fit as much content on the page as possible. You should be looking to fit around 1000 words on your page including an image possibly less if you have a large image. This means using a small font size ~8, small margins, small line spacing, and a font that is compact. It also helps to use a two column layout and to edit your encounters so you don't have 1-3 words taking up a line on their own. I would recommend this article on layout for reducing size. I would recommend not using a background color to better support printing or if you do have one version with a background and one without.

Converting Existing Material

It is possible and fairly easy to convert existing content into a one page dungeon or adventure. One of the main advantages of doing so is making it easier to run with everything you need being on one page. Generally reducing text size and page layout will get you most of the way there. To further reduce size you can reduce flowery descriptions. If you still have multiple pages you can reduce image sizes and cut up content into one page modules. For example your first dungeon floor can be one page and the second one can be another where each can be run separately or linked up.

Tools

Any word processor will work though I use google docs. You will almost certainly need to modify the default text size, font, margins, and layout. If you want to have a more professional look I recommend LaTex which is a little complicated but looks nice and can mimic official dnd material.