Dungeon Design in 4E

The year 2000 was a heady time for D&D players. 3rd edition was finally released after a year of previews. A game that had almost fallen off the radar of gamers everywhere came back with a bang. There was a tangible sense of energy in the air at Gen Con that year. People were excited about the toys they read about in their shiny new Player’s Handbooks and, better yet, the toys were incredibly fun.

Thus, it was with some surprise that, when I returned home from Gen Con and set to work on my first adventure, I was a little unhappy. According to the rules, a 1st level party could face a single Challenge Rating 1 monster, or an Encounter Level 1 group of beasts. That seemed reasonable, until I started designing adventures. The rules presented the following possibilities:

One gnoll
One troglodyte
Two orcs
Two hobgoblins
Four goblins

None of these really excited me. Four goblins on the map might be fun, but a fighter with the Cleave feat put that thought to bed. I wanted Keep on the Borderlands and the moat house from Village of Hommlet. My dungeons felt boring because I couldn’t fit many monsters into each room.

Admittedly, 3rd Edition brought some sense and standardization to encounters that other editions glossed over, but that didn’t change a simple fact—I wanted lots of humanoids running around my dungeon rooms, and 3rd Edition said I could do that only if I wanted a TPK.

Over the years, my initial frustration with the game never faded. By the time the party was of a high enough level to handle a fight with six orcs, the poor orcs’ AC and attacks were too low to pose much of a threat. In the end, I just fudged my encounters to create the excitement and variety I was. Despite what the game told me, a low-level party could take on three or four orcs without a massacre (for the PCs, at least).

The 4E Way: Monsters, Monsters, Monsters!

In 4th Edition, your dungeons are going to be a lot more densely populated. The typical encounter has one monster per PC in the party, assuming that the monsters are about the same level as the PCs. An encounter’s total XP value determines its difficulty, allowing you a lot more freedom to mix tougher and weaker monsters. Even better, the difference between a level X monster and a level X + 1 monster is much smaller. You can create an encounter using monsters that are three or four levels above the party without much fear. Add in the rules for minions (which will be described in a future Design & Development article), and you could (in theory) match twenty goblins against a 1st-level party and have a fun, exciting, balanced fight.

This shift in encounter design means a lot for dungeons. With all those monsters running around, you need to give them a fair amount of space for a number of reasons:

The monsters need to bring their numbers to bear on the party. Wider corridors and rooms allow the monsters to attack as a group. A monster that’s standing around, waiting for the space it needs to make an attack, is wasting its time.

Multiple avenues of attack make things scary for the PCs and make it easier to get all the monsters into the action. The typical dungeon room where the PCs are on one side of the door and the monsters are on the other grows dull after a while. The PCs kick open the door, form a defensive formation in the doorway, and hack the monsters to pieces. There’s little tactical challenge there.

Reinforcements need a route to the battle. With more monsters in a fight, you can design dynamic encounters where the orcs in the room next door come barging into the fight to see what’s going on. An extra door or passage in the encounter area is a convenient route for the rest of the encounter’s monsters to show up on the scene. Just because the encounter calls for five orcs doesn’t mean that all five start the encounter in the party’s line of sight.

Example: Dungeon of the Fire Opal


As part of an early playtest, I dug up a map that 1st and 3rd Edition veterans might recognize. Here’s an example of an encounter I built using the basic philosophy outlined above.

Notice that the map marks these rooms as separate areas, three 20 foot-by-30 foot rooms. Measured in squares, that’s 4 by 6, small enough that even a dwarf could stomp from one end of the room to the next in one move action. That’s doesn’t make for a very interesting encounter. If I tried to squeeze four or five monsters into each of those rooms, there would be barely enough room for the party and their foes to fit. The fight would consist of the two sides lining up and trading attacks for 3–4 rounds. Few inherently interesting tactical options can even come into play.

Even worse, the map offers few strategic events. The monsters might flee out the secret door in area 9 or one of the doors in area 8, but with such small rooms it would be easy for the PCs to block the exits or move next to any of the monsters before they could run.

When I went back and used this map to design a 4th Edition adventure, I combined all three rooms into one encounter area. Area 9 was a torture chamber staffed by four goblin minions. Area 8 was a guard room manned by two hobgoblin warriors, while the bugbear torturer lounged in his private chamber, area 7. In play, the party walked south toward area 9, ignoring the door to area 7 for the moment. The rogue and ranger tried to sneak up on the hobgoblins in area 8, but the monsters spotted them and attacked. When the hobgoblins yelled for help, the goblins charged from area 9 and the bugbear emerged from his chamber to attack the party’s wizard from behind.

The fight was a tense affair in the T-intersection between areas 8 and 9. Caught between three groups of monsters, the party had to constantly move to protect the vulnerable wizard, heal PCs who fell to the combined attacks of the hobgoblins and bugbear, and spend precious actions hacking down the goblin minions.

I didn’t do anything fancy with the map or add any magical elements to the fight. It was simply a tough melee in close quarters with attackers coming in from three directions at once. The dungeon was a dynamic environment, with three groups of connected monsters responding to the PCs’ intrusion into their area.


So, that’s the first rule of 4th Edition dungeon design. Now that you have more monsters to throw at the party, you can create encounters that spill over greater areas. Opening a door in one area might cause monsters to come from other areas of the dungeon to investigate. With the emphasis switched from one party against one monster to one party against an equal number of foes, you can throw a lot more critters at the PCs.

Homework Assignment

4th Edition is still a ways off, but it’s never too early to start thinking of the dungeons you’re going to design. Here’s a little homework assignment for all of you: Pick two or three closely linked encounter areas on the sample dungeon map. While you obviously don’t have access to the new rules, you can still come up with ideas for encounters. Assuming that you can use four or five monsters, pick two or three encounter areas on the map and turn them into a single fight. Post your ideas in the 4th Edition forums and see what other gamers come up with.

by Mike Mearls / Art by Christopher Burdett