They're the bottom rung of dungeon design. Draw a "cool dungeon" on a piece of graph paper, throw in some loot and some monsters to defend it. So generic your browser can do it. There might be some semblance of a storyline to patch the thing together but generally it's of the sort that can be fit on a scenario card; read at the beginning then promptly forgotten and lost beneath the pizza box. There are a lot of these types of dungeons around, particularly in computer RPGs and, to be fair, they have their place. They operate as a vehicle of challenge and loot delivery. Rooms full of combat and particle effects. Not many people play Diablo with the storyline being their prime motivation to keep going.
As a narrative device, however, these dungeons fall pretty flat. Imagine Diablo as a table-top RPG:
"You bash open the door with your +40 hammer of fire! There are 25 giant blue lightning beetles and a treasure chest!"
(three hours of die rolling later)
"The last beetle is dead. In the chest is a +41 hammer of ice! In the next room there are 50 giant red fire beetles and a treasure chest!"
The way we fix this is through story. A good dungeon tells it's own story. It has a beginning, middle and end, the rooms and corridors its paragraphs and sentences. It has an antagonist, it has subplots, it has twists and turns and cliffhangers, both figurative and literal. The dungeon itself becomes a major character. I had to do a fair bit of thinking about how dungeons and stories interact over the course of writing The Dungeoneers. So I'm going to let this ramble serve as an introduction, of sorts, to a series about combining story and dungeons. I'll talk about what a dungeon is, what purpose they serve, using their linearity to your advantage, getting the correct feng-shui, making a dungeon a living place, etc. That sort of thing.
I'm not doing this to try and present myself as some sort of dungeon design genius endeavoring to teach disciples the way of dungeon design -- more as a way of generating conversation about these aspects of dungeons and ways to utilize them. Conversations that can serve as inspiration and launching points for DMs to find new ways to keep the dice rolling.
So, coming up next: Just what the hell is a dungeon, anyway?