The other day I was talking to a fellow dungeon master and good friend of mine. I asked him what makes a good dungeon and a good dungeon crawl. He answered: A good dungeon is dangerous and exciting to crawl! Though the answer may seem simple there’s a lot more to it. 

Dungeons are an essential part of D&D and creating one can be very giving and fun. There seems to be a dungeon in almost every published module , that the PCs need to crawl, but, obviously, not t all of these dungeons are good, dangerous or exciting to crawl. But how to achieve that? How make sure that your players find your dungeon exciting and fear for their character‘s lives?

A few essentials to dungeon-crafting

Type of dungeon

First, you need to decide what kind of dungeon you’d like to create. As a ground rule, there are two different types of dungeons, those that the PCs can enter and exit at will, allowing them to make multiple entries and crawl a little further each time. The Tomb of Horrors is that kind of dungeon. Even the Acererak the demi-lich created one of the deadliest dungeons of all time, it allowed the PCs entering the dungeon to leave it to rest and get more supplies.

The other type is the dungeon where the PCs can’t leave and need to rely on finding places to rest within the dungeon itself. A sample of this kind of dungeon can be found in the 5E module Out of the Abyss, where the PCs start as prisoners in drow hold and need to find a way out into the Underdark.

The Why’s and Who’s and the Objectives

Essential to all rpg modules is the story. The PCs need to know why they need to enter the dungeon or why they are there. They also need to discover the who’s, e.g. in Night Below the PCs slowly uncover the Aboleth plot, in Rick Swann’s Nightmare Keep the PCs through their investigation of the strange insects discover the leads that takes them to the Keep and Icelia’s dungeons, in the Sunless Citadel the PCs hear about the citadel in Oakhurst before entering it.

In all of these modules the whys, whos and objectives are clear. Not necessarily all at the start, but these important driving forces of the narrative are there. When creating a dungeon, you need to make sure that these are there as well.

But having them is not enough, for sometimes even the most obvious hints go unnoticed by the PCs. In the module Labyrinth of Madness, the PCs are to collect some 20 sigils tattoos on their arms before being able to confront the evil lords of the dungeon, but unfortunately that part of the module isn’t well laid out and if played as-written, that part might be overlooked by many players, to their much frustration. So, make sure that these essential parts of the narrative is easily accessible and understood by the players.

Making it dangerous and exciting

Dungeon features

In every module, especially the latest ones, there’s a description of the dungeon features. When you create a dungeon, don’t skimp on the dungeon features. This is what makes creates the feel and look of the dungeon. Is the dungeon beneath a ruined keep, all dusty and dark? Or is the dungeon in some weird part of the Underdark where mushrooms, lichen and Lovecraftian, tentacled monsters rule supreme? Or is the dungeon an underground complex, created by mad wizards, like Undermountain?

Make these features count. If there’s no light in the dungeon, make sure that the players spend some of their resources on light sources, be it spells, torches or lanterns. If the dungeon floor if made of uneven rock make sure it has some systematic effect, e.g. the PCs need to make Dexterity Saves to keep balance in some areas or it slows their progress (or retreats from dangerous monsters) in some way.

Maps are of course essential to a dungeon, but I often feel that the players’ need to map is over-expressed. In a labyrinth, where the chance of getting lost is high, why draw them out a map? Let them do it themselves. Get them involved in the book keeping, let them draw out their own map, though, of course, you draw out the battle maps. One of the thing that makes a dungeon exciting and dangerous is to be always guessing, to not be sure if they’re on the right path or if the group’s map maker’s map is entirely correct.

Traps

Many DMs love to create crafty traps. Traps can get even the most veteran players cling to the edge of their seats, hoping against hope that their beloved PC will escape, at least mostly unharmed. Traps are a double-edged sword and need to be administered with care, for if the PCs are dealing with too many traps and puzzles the pace of the narrative tends to slow down to a crawl and most traps only reward few members of the group.

Though it can be fun to create traps and pit the players against them, I often feel that traps are not necessarily in line with the whoever was supposed to create it, e.g. kobolds love to create traps but is as a race not a smart one, therefor one could argue that their traps would be simple. Many layered traps, including both magical sigils and crafty engineering, is something that only the most intelligent races, i.e. beholders or mind flayers, would use.

Finally, here’s one tip about traps. Often what makes players feel that a dungeon is dangerous, is not the number of traps. It’s the fear of traps. As a DM you can get this feeling across to the players by asking questions, e.g. what is their marching order? Who is holding the torch? What is their encumbrance? Even asking questions about their most simple actions, can make the players feel afraid for their PCs lives, e.g. are you using your right or left hand to open the chest? Even though most of the times their answer doesn’t matter, but as you dot down their answers, and the more answers they give, the more tense they become. You can use their answers from time to time (ah, that chest was a mimic who bit the PC’s hand, forcing her to use her off hand), to show that their answers count for something, though not nearly all matter.

Monsters and their knowledge of the dungeon

Too often, when reading through modules, I feel that the inhabitants of the dungeons are bound to specific rooms or that the inhabitants of the dungeon aren’t expected to react to the intruding PCs. When you’re creating a dungeon don’t forget to note what the monsters and other inhabitants of the dungeon know about the dungeon or how they communicate between themselves. Are there sentries or guards? Are there magical wards that alarm the evil boss about intruders?

Intelligent and super-intelligent monsters would always respond to intruders by setting up ambushes, where they have the higher ground, pitting the PCs against the forces of the dungeon when it suits the PCs the worst. Even a clan of kobolds, when confronted by intruders to their den, would set up defenses and try to fight of their attackers, though their defense might not be as advanced as in the lair of a beholder.

Test the PCs’ strength

Every encounter doesn’t need to be deadly, but it needs to be dangerous and confer some disadvantage to their group, e.g. it uses up their resources. When creating a dungeon, I find it helpful to create encounters and events that test different skills of the PCs. A dungeon where every door is locked only tests the rogue type’s abilities to pick locks. A dungeon where the doors are both barricaded, stuck, trapped, locked and magically warded tests more type of skills than just the rogues’.

Make sure that the encounters wary. Crawling from room to room in a dungeon infested with goblins, can get boring quite quickly (if you’re not into hack ‘n slash) if there’s no variations to the rooms. Fighting off 3 goblins on a swinging rope bridge over a 60’ deep chasm is way more interesting that entering yet another room where 3 goblins have made their nest.

Test the PCs’ weakness

Just as you know the PCs’ strength, you should know their weaknesses. Is the fighter’s wisdom save poor? Let the PCs make a wisdom save, albeit a low one, at crucial moment, one that could seriously affect the PCs chance of survival. Testing not only the strengths of the PCs, but also their weakness makes the dungeon dangerous, especially if you use it at the opportune moments.

The key element to make a dungeon feel dangerous, but not unfair, is to make sure that there are multiple ways to complete it or to reach the objectives. Even though the fighter ran away, frightened by the evil overlord, the overlord can still be overcome by the rest of the group.

TL;DR

To cut it short, to make a dungeon feel dangerous and exciting isn’t about using monsters with high AC or plethora of deadly traps. It’s about depleting the PCs resources, using the dungeon to their disadvantage and testing their strength and weaknesses.

Rewards big and small

In D&D many players love the chance of hitting it big, to find the motherload of all magical items and chests full of gold. When creating your dungeon make sure that the rewards are in line with the danger and the inhabitants of the dungeon. A clan of troglodytes might collect some gold, even have acquired a magical item or two, but a +5 intelligent longsword would soon find it’s way into other hands than theirs.

You also need to consider when to hand out treasure and other rewards. If the PCs crawl a dungeon infested with kobolds, who are slaves to a red dragon, the chance the the kobolds have much treasure is slim, due to the red dragon’s greed. You also need to decide on if the rewards, when handed out, can be of some help to the PCs at that moment, e.g. in the very hot dungeon under a volcano, water is a precious thing, and the players need to keep track of their water sources, rewarding them with a Decanter of Endless Water can have serious effect on their chance of survival, while a decanter full of gold coins, could make the PCs happy, though only to find out that gold has never quenched anyone thirst.

Keep it fun

If you make sure that everyone has fun, you created a great dungeon. You know your players, you know what makes them tick. If going murder-hoboing through room after room, slinging spell after spell, slaying packs of rats and tribes of giants is all they need, perhaps you don’t need that complex dungeon. If your players like more complex, multi-layered dungeons where politics, diplomacy and subterfuge is needed, you need to be more creative. As long as you keep it fun and remember that this is not a competition between players and DM, you’ll succeed.