Megadungeon Design and Philosophy - Part 1

There are certainly many ways to design a Megadungeon. In fact, one might argue that there are as many different ways as there are DMs, and each of those DMs might actually have a few different approaches they might be working from on different projects. Nonetheless, there are some good, common sense points to be made regarding the subject:

Think Big
Think about the number of rooms you want to detail on a given level (say, 42), and then multiply that by two, or even three. That's how many rooms you really have on that level. I'm not saying you should detail three times as many rooms, but that Megadungeons need empty space. Its important to the whole concept. The Megadungeon shouldn't feel like a series of consecutive rooms, each filled with its own monster, treasure, and trap to overcome.

A Megadungeon level should convey a feeling of "immense", "unending", etc. In other words, there should never really be a sense that a level should be "cleared", as there is with a more conventionally sized dungeon. The motivation in delving deeper in the Megadungeon should come in your presentation - helping the party realize that the rewards in treasure and xp will grow ever larger, the deeper they dare to go.

All those empty rooms help convey that feeling of BIG, and they also give you room to flex your improvisational chops a bit. Fun DMing is not, imo, just reading off a bunch of predetermined encounters, but getting to interact with the world just like the players get to. Keeping a bunch of unfilled rooms lets you dig out the randomization charts, add stuff to further the plots that will develop in play via the characters' actions, and let you provide fresh areas to explore for new 1st level parties, whether that be from DMins multiple groups, or because of the occasional TPK!

Think Small
The best way to make the Megadungeon environment feel alive to your players, as opposed to being just a collection of random squares and rectangles, is to focus on the details. Megadungeons can take years to design; who wants their players to just rampage through it at maximum speed? If you want your players to slow down and enjoy the place, give them a reason to.

Always remember to take the players' senses into account. The Megadungeon should vary between ominous, tomblike silence, and a constant buzz of background noise. Stuff like distant screams, wails, clangs, crashes, trickles, vibrations, gongs, crackles, etc will usually prompt investigation and keep players alert and, most importantly, nervous.

The eyes are as important as the ears. Its all too easy to allow the Megadungeon to slide by as featureless gray walls. Give them some color. Make that 100' long corridor be composed of yellow and purple brickwork, held together with some bizarre inky black plaster, each stamped with a mason's rune from a bygone age. Or have the floor of that supposedly natural cavern appear to have been inset with checkerboard-like black and white marble tiles. These simple features will make even the emptiest rooms memorable, and players will no doubt want to take their time exploring further, maybe even conducting research outside of the dungeon at the local library or museum, etc.

Smells, temperatures, air quality, air flow, "weird feelings", all are vital to bringing the Megadungeon off of that sheet of graph paper and placing it deep into the players' imaginations.

Connectivity
One common mistake, easily made, is to place too much emphasis on the levels, and not so much on the connections between them. Without vivid, detailed, and well-thought connections between the levels, all you really have is a collection of ten different dungeons, linked weakly together by the odd stairwell.

Its important to get a three dimensional image of your dungeon. Think about where the levels connect, and design the levels around those connections. Think about how massive places in real life are organized, be it your local shopping mall, theme park, business centers, urban districts. Notice how things are grouped around and organized according to connectivity. High traffic areas are important, to vendors, police, even criminals. As you move away from those connections, things get smaller, seedier, more spread out, darker, etc.

You can apply those same grouping tendencies to the connections in your Megadungeons. Areas near the main connections between levels may often feature larger chambers, great halls, etc, with more traffic, special guardians, and depending on the amount of adventuring traffic, may not have as much in the way of treasure. Similarly, as you move away from these connection points, things will get more spread out, traffic will decrease, and many chambers may not have been disturbed for a long time, which means the possibility of greater rewards.

For the actual connections themselves, try and detail them beyond the usual "stairs down". You could use huge, ballroom-style staircases, with rich marble steps and ornate balustrades. You could have sweeping, concave ramps obviosuly suited for more alien traffic than human. Immense waterfalls, underground cliffs, rickety, swaying elevators, wind-filled chutes, platforms raised and lowered via water pressure, and anything else your imagination can devise.

Stay Tuned
Next installment will discuss Grouping, the Nature of the Underworld, the importance of ceilings, those two dirty words "Dungeon Ecology", and more.