In the older running of the now two D&D games I find myself DMing, I ran my first successful dungeon recently. I say first successful, because for the first time I feel the dungeon ran smoothly. Yes, it had challenges and hiccups that the players had to deal with, but at the table it ran smooth. I don't owe this smoothness to extended prep time - though it did involve that. No, I owe it to using a random dungeon map and filling that in with what I needed - and fixing what I needed to what it offered. Today I want to talk about that.
I Hate My Own Work
One of the things I should clarify is that when it comes to building designs, or dungeon designs, I tend to hate my own work. I'm not sure what it is, but my stuff is never up to muster. I'm not saying it's good work but I lack faith in it. My designs are...rough...at best it feels. I don't have a full comprehension for how things are supposed to go together and so I always feel like it looks awkward, if only because I know that what I have is just random lines.
However, put a map- or blueprint for a building- in front of me and if I like it I can make it work. That is what I did here.
I used donjon.net's random dungeon generator. This tool is awesome. It can build the entire dungeon for you. You give it the level and size of your party, the theme for the dungeon, and a few other control bits - like layout type you want - and it will give you a whole dungeon complete with traps, encounters, wandering monsters for random encounters, and treasure. It's incredible.
I looked over all that extra fluff and content for ideas - and some of it stuck - but mostly I wanted the map itself. Just the layout of where corridors are vs. rooms vs. doors and that sort of thing. Trust me, random generation done by an algorithm looks better than anything I've ever come up with.
The next step with the map is to apply the NPCs to the map. The dungeon was built, or purposed, by this group and so it's important to have their flair there. Why do they have the layout they have is one question you have to answer. You also want to keep the monster in mind when setting traps and encounters. Kobolds are going to leave different traps than Dragons, and a group of bandits with no magic to their name aren't going to fill their base with a bunch of lightning bolt traps. Right?
Make Small Modifications As Necessary
Sometimes parts of the map don't work with what the story says should be there, or what the NPCs would do. In those case, just make a simple modification to the map. Add corridors, rooms, or whatever else you need. You can only bend the characters to the map so much, and when you pass that point it's time to bend the map to them.
Remember Not To Make It Too Hard To Get In
One of the things some dungeon makers forget is that the dungeon has to be navigable by some means. I don't mean as game balance, but as a story. There is an old addage, make it too hard to get in and you can't get out. The same is true for dungeons. A Dragon isn't going to be interested in a lair they can't escape or leave, and there is no point in having a dungeon set up to guard something if you can't get to it when you want to.
Odds are there is a specific type of intruder that the owner of the dungeon is trying to keep out, and that should be kept in mind. Every encounter in a dungeon shouldn't be a hard fight - unless the dungeon was specifically set up for the PCs. And the dungeon should be set up with a number of approaches in mind to defend against.
Don't Underestimate Curiosity
As a final tip, don't underestimate curiosity of the players. Some traps can be blatantly obvious. As obvious as a level just sitting out in a hallway. Many players, especially experienced ones, will 'clear' the dungeon to make sure they get everything, and that can be used to make sure they hit some of the snags while their approach may help them skip others.
Ultimately, you should have fun with it. Have fun building the dungeon. Have fun running the dungeon. Just remember, the Players - but maybe not their characters - should be having fun too.