1. Nature of the opposition.

Defensive, Competitive, or Retrieving.

            A defensive dungeon is one where the bad guys live. This is most dungeons where the PCs are essentially invaders, an example being where the PCs are raiding a goblin hideout. Generally these dungeons have guard rooms and barracks, but not too many traps, lest the bad guys fall over their own traps. Most treasure is probably in one well-guarded central room or vault. The idea is to wipe out the enemy.

A competitive dungeon is one where the bad guys themselves dont live there. This is a dungeon that the bad guys are exploring as well. An example is where both the PCs and a group of orcs are trying to reach the center of a tomb to steal an artifact. There are usually many traps, and the bad guy may fall afoul of them as well. In this time of dungeon time is of the essence, because if the PCs dilly-dally then the bad guys get away with the prize. The idea is to beat the other side to a goal.

A retrieving dungeon combines the other two, where the PCs are entering a cave system full of hobgoblins, but the PCs are trying to rescue a captive or find a rare herb as opposed to fighting and killing all 200 hobgoblins. This emphasizes stealth rather than head on fighting, and the hobgoblins pet wolves may be a bigger challenge than the hobgoblins themselves. The idea is to get in and get out, and not deal with every obstacle there.

            Of course one can combine these different factors.

2. Size.

Large, medium, small?

            This seems like a simple question, but it affects how long you want the adventure to run. Small dungeons have 3-10 rooms, the rooms are usually not bigger than 20 by 20 feet, and many of the corridors will be 5 feet wide instead of the usual 10 feet wide. There is probably only one secret door.

            Medium sized dungeons have mostly 10 foot wide corridors, possibly a water source, and several secret passages. Expect 8-15 rooms with sizes from 20 by 20 feet to 40 by 30 feet. Bigger rooms will have pillars in them to hold up the ceiling.

            Large dungeons are large. They have central meeting halls, rooms with high ceilings and butresses, and perhaps catwalks over ravines. Some rooms may have ladders that lead up to archer positions. Expect 12 25 rooms of all sizes.

3. Nature of the site.

Dynamic or Static?

            Some DMs want to decide this first. Does the dungeons not change much, or is it always changing?

            An extremely dynamic dungeon is one where kobolds live on one side, goblins on the other, and they are at war. They constantly hire evil monsters and summon demons and devils. They often dig new tunnels to ambush their foes. Traps last for perhaps a week until they are tripped, and patrols are strong. (Many wandering monster charts)

            An extremely static dungeon is a tomb. The big undead guy lies trapped in a coffin in the middle. (A mummy or a vampire, sometimes a lich) There are many, many traps, because traps just sit there. There are probably several lesser undead. There may be one section of the dungeon exposed to the elements where giant spiders or carrion crawlers live.

            In between these two extremes lie many other types of dungeons. Sometimes one-half of the dungeon is one thing, one half is another.

4. Origin.

Natural structure or created?

            Are these natural caves or dug fortifications? Or a combination?

            Natural caves will have less mechanical traps, but they can have natural hazards like slippery spots, flash floods in the tunnels (See drowning rules in the DMG), and dangerous plants. There is almost always a water flow somewhere in a natural cave. It is also a great place for unintelligent beasts to hide. (Examples: Carrion crawler, dire ape, etc.) Little is known about them.

            Something dug by someone usually means that an architect planned it. Also, someone lived there or used it before it became a dungeons. These means that if the PCs make good use of their Gather Info checks it is fair to let them know about details or even give them a partial map.

Example: A clerical order has an abbey. They sell wine to support the abbey. They dig a series of wine cellars to hold the wine. They stick a vault down there with their magical goodies while they are at it. One night orc raiders attack the abbey and burn it down. The wine cellars are underground, and therefore intact. Some hobgoblins move into the wine cellars, finding the wine tasty and the cellars to be well-fortified. If the PCs do enough investigating before the go on the adventure, they may find an old man who worked at the abbey as a boy, who can tell them where the secret passages are that the hobgoblins didnt find yet.

Created structures are also more likely to have hidden traps. They might have decorations as well, and the decorative carvings are likely to give clues or hide secrets. A statue that comes to life and attacks PCs fits more in a created structure than a natural one.

Of course dungeons can be a combination of both. Dwarves or gnomes dig a burrow for fortification, and break into a cave system, freeing a demon. Now the dwarven/gnome hall is empty except for undead, and the demon has started to hire orcs to form an army. This could be a defensive set up where the PCs go in and wipe the bad guys out. It could be a competitive set up where the PCs are trying to find the secret dwarf treasure room before the demon does, because the dwarves hid an Axe of Defeating Demons there. A dwarf NPC may even come with the PCs or hire them.

5. Purpose.

Created for what? Tomb, Vault, Storage?

            This is really a subsection of question 4. Whoever dug this place out, why did they do it? If they made a vault, expect traps and undead, and maybe a gang of bandits who are waiting for you when you come out. If this place used to be a storage facility, what is still in there? If it was a hidden base for creatures, who built it? Kobolds build clever things, hobgoblins build straightforward things.

            This is not the same as the first question, because an underground cistern built for water storage can still be a defensive dungeon if a group of hobgoblins or evil fey are making it a forward base. It can be a competitive dungeon if a magical key baked into a brick is at the bottom of the reservoir and the PCs are racing against a group of druids for the key. It can be retrieving if a group of pirhana have been placed there.

SAMPLE DUNGEON

Retrieving, Medium, Dynamic, Created/Natural, For Study.

 What does all that mean?

            Well, lets say that a dwarven sage built an observatory atop a mountaintop. It was a good place to study the stars. There is a hemispherical building with a big telescope. The sage hired gnomes to build stairs going up to the top. However, the gnomes found that seasonal blizzards halfway up the mountain complicated things. The gnomes consulted a druid, who found a series of natural caves for them, carved out by ice melt runoff. The gnomes chiseled and dug, and made a gateway dungeon to the cave system, where they built catwalks and staircases going up.

The dwarven sage had a good time watching the stars, until a frost giant who lived in the mountains saw the twinkling of sunset of the lens of the telescope, traveled to the observatory, and ate the sage. The forst giant then proceeded to live at the observatory, finding it interesting.

Given dwarven clan loyalty, it was not long before dwarven warriors came looking to kill the giant. They came close. The giant realized that he might not defeat the next group, and that he could not fit into the caves to guard them. So the giant negotiated a deal with some orcs, getting them to move into the caves and guard the giants back door. Not fully trusting the orcs, the giant also caught and then released several beasts in the area.

So: Theres an entry area and a gate to the caves, guarded by orcs. There are perhaps 4-5 rooms and a central corridor. Not built for defense, it should be easy to move around in. (No traps and 10 foot wide corridors.) Most of the orcs are there. They may have piled rocks in areas for archers to hide behind, but that is probably the extent of their architectural improvement, since orcs are savage. On the other hand, orcs will have a shaman or a cleric come bless the area, and the cleric will probably move in, so the PCs have a spellcaster to contend with.

Beyond the entry area are the caves with their catwalks and stairs. Here is where is pays to have a high balance skill, because orcs with bows on the stairs can knock someone over into the cascading water. On the other hand, the water noise makes listen checks more difficult, making it easier to sneak up on the orcs. The orcs here probably have bows instead of javelins.

Along the way there will be caves with standing room that have orc warriors. Halfway up is a carved out storage area made by the gnomes, which the orc chief (high level barbarian) may have taken over.

Near the top the frost giant probably has a few trained winter wolves.

There are few traps in this dungeon. Orcs arent really clever enough to make them, and the giant is not nimble enough. The treasure probably consists of scholarly books and items in that observatory which could be sold for a lot of money in a major city. There may be magical items that deal with divination. The various lenses and spyglasses constitute regular treasure. Perhaps the deceased sage had a hidden vault that the giant did not find.

As this adventure stands, a rogue with disable device is not too helpful, given the lack of traps. A rogue with a high balance check, or a monk, would be very valuable, especially when fighting on the catwalks. Paladins would come in very useful with their detect evil finding the hiding orc archers. Dwarven characters get extra bonuses fighting orcs and giants. Any character with a high charisma or gather information check might find a surviving gnome who can tell them about the place, or maybe some architects schematics in the city library. Wizards and sorcerers come in handy so long as they arent surprised. Clerics should be healers and fighters, there are not too many undead here, save a skeleton obeying the orders of an orc cleric. Druids may summon some water creatures to help deal with the archers.

Now lets change some things. A vampire/wizard takes over the observatory. He drains the sage and turns the sage into a vampire subservient to him. The dwarven sage writes letters to his clan, summoning them because he has discovered gold. The greedy dwarves fall for it and come, only to become vampire fodder. Now the cave/stairs up are crawling with vampire spawn. Some goblin spies hear about the gold and the goblins show up. Many are slain, until the goblin cleric rebukes the undead. The vampire ends the standoff by getting the goblins to guard the entryway at the mountain bottom. The goblins guard the vamps by day, the vamps guard the goblins at night.

In this adventure, PCs are dead without a cleric, and they probably need a paladin too. A Ranger whose favored enemies are goblinoids would do very well, because after killing a bunch he could add his favored enemy bonus to intimidate and diplomacy checks with the goblins. He could very well convince them to head elsewhere, then the PCs could climb up the mountain by day and attack before the sun sets.

Alternatively a UFO of mind flayers sees the telescope, lands their craft atop the observatory, and makes the sage their mental slave. Again the sage writes to his dwarven brethren. Now the dwarves come, become mental slaves, and the dwarves fortify the complex! All of the sudden rogues with high disable device checks are very necessary, but so are PCs will high will saves given the mind flayers abilities. Good PCs will have to avoid fighting the dwarves who are not responsible for their actions. Stealth now serves the PCs better than brawn. Break enchantment spells will turn enemies into allies.