You can build complex mega dungeons and campaign settings with one page dungeons. These small dungeons are a great tool in any game masters tool kit for simple dungeon design. They are short, modular, and are easy to both write and run sessions with. They are typically structured with 5-7 elements and a map of the dungeon all fitting on a single page. While they are useful as individual story beats in a campaign their limited nature tends to make it difficult to run a long format adventure using them but that is a problem we can fix.
What are Key Pages and Nesting
You should use key pages and nesting to build a world that is both complex and simple to write and run. Nesting consist of one page dungeons and key pages which connects them. A useful key page will follow the same principles as a one page dungeon and consist of a map and a handful of elements on the map. Unlike a dungeon however your elements on a key page should be short descriptions referencing a one page dungeon you have prepared or are planning on writing in the future if you need it.
Key pages are flexible since they are mostly organization tools to make it easier to run sessions. You can have a key page that covers a single floor of a mega dungeon with your one page dungeons being different sections of that floor. You can also nest key pages so if you have multiple mega dungeon floors you can create a key page linking those together so you have a mega dungeon key page with all your floors. This method scales well and lets you build very concepts in small manageable chunks.
Example of how to design a mega dungeon with one page dungeons
Mega Dungeon Key Page
Floor One Key Page
Skeleton Pits One Page dungeon
Boneyard One Page dungeon
Skeleton King One Page dungeon
Floor Two Key Page
Alchemy Lab One Page Dungeon
Plague Lab One Page Dungeon
Lair of the Necromancer One Page Dungeon
Extra Information on Key Pages
This structure works well but sometimes you will have information that doesn't make sense in your dungeon that links it together with another dungeon. Things like secret passages, important lore, or individual encounters that are related to both. Key pages are a useful place to put this information and it can be mixed in with dungeon references. A map showing connections between the dungeons allows for complex path choices for exploring. Small rest stops connected between the dungeons allow for places for players to catch their breath. Overviews of how all the different dungeons logically link together in your overall story are also handy to have on a key page.
