Undermountain

Undermountain is a large module, a mega-dungeon, placed below a seaside metropolis called Waterdeep in the Forgotten Realms. The original boxed set (including the first three levels of the dungeon) always fascinated me, partly because it was the only mega-dungeon I had read.

The level maps are on poster-size paper, the squares representing 10′ of space are tiny. It’s really quite large. That’s one of its problems. The DM can’t hide the map (which does show secret areas and such) and it’s hard to handle behind the screen. I’ve seen one DM use black construction paper to hide sections of the map from players but that doesn’t hide the secret doors and marks in the keyed rooms.

That’s a second problem: the dungeon is not entirely filled-out. The central, or core, areas are detailed but the outer areas are not. Only about a tenth of the dungeon’s space is keyed. And these outer areas are often bland or stupid-looking, as if the cartographer just needed to fill up the space with something and it didn’t matter whether it was good or not.

But Undermountain drew me in because of its promise. It was not a dungeon you could clear out, or “finish”. It was just too big. And it had a reputation. And it could contain everything from horror to whimsy because of its background.

So I decided to make my own version of Undermountain. Not only to make my own maps and rooms, but to change what was already there so people who had played it before would discover pleasant (and some not so pleasant) surprises. I decided I needed an outline for each level, level maps, random encounter charts, and room descriptions. And then it would virtually run itself!

Internet Research followed. For a DM, Internet Research is a cunning euphemism for “finding someone with ideas and stealing them”. I’m not publishing this turkey, why should everything come from my head, right?

My outline gave me some cool ideas for Level 1 all the way down to Level 7. You might not think much of this, only seven levels, but the levels were widely spaced and there would be sub-levels between. In all, we’re talking about a depth of 2100 feet. The outline also defined the size of a level. I decided to base my level size on 4 square per inch graph paper, 8 x 11 inches. 10′ per square. So one sheet would cover 32 squares by 44 squares. Each level was five sheets by five sheets. They were labeled like Excel cells, with letters across the top and numbers down the side. Each section had multiple connections, many secret, to neighboring sections. I drew sewer grate style small tunnels between rooms, water pipes, etc. The dungeon was 1600′ by 2200′ per level. Almost a square mile of mapped 10′ squares not counting sublevels, of which there could be 2-3 between each pair of levels taking up one map page per sublevel.

(The original, 155 squares across)

(Mine, 160 squares across)

Lots of mapping. In MS Paint. Each 10′ square was 18 pixels across plus a 2-pixel border. A square owned its side of the border, so effectively each square was 20 pixels wide unless there was a wall. Walls were a full 2 pixels wide. Ledges were only one pixel wide.

I actually made it through mapping Levels 1-3 and then started keying rooms. The core rooms I mapped closely to how they appeared in the boxed set. Their descriptions were slightly altered. For example, in the hall of mirrors, instead of expecting someone to come by and fix the mirrors occasionally, I had the shattered glass melt and evaporate and the frame grow new glass like it was a sheet of crystals. And the space behind the 10′ square frame was a 10′ cube room which could hold just about anything. It was a pretty tight little ambush room, though they never got ambushed in it. Oh and one randomly-shuffling mirror at a time would grow a Mirror of Opposition and another would grow a random magical mirror, which might be beneficial if you looked into it.

Anyway, my Internet Research scrounged up one excellent resource. A guy (I know, [Citation Needed], right?) had detailed many of the rooms on the original Undermountain map for Levels 1 and 2. Many of the room descriptions were too transient and were more like encounters, so I tore them apart and used ideas for my encounter lists. But many were good tricks and ideas.

I found a riddle forum that was an excellent source of inspiration for tricks and traps. various netbooks, mostly full of dreck written by simple folk, but with some gems. Architectural sites, news articles, travel documentaries, etc. It was all fuel for the growing monster that was Undermountain. And of course every thing I came across sparked some little bit of inspiration in me. I was carrying a notebook at the time and would jot down anything interesting.

So it came time to actually choose which rooms would be keyed to which descriptions. The Word doc holding my rooms became too slow to open and save, so I split them up by level. That held off the inevitable for a short time. I realized that my numbering scheme of 122 for Level 1, Room 22 wouldn’t work because I had far more than 100 rooms per level. I decided number/letter for the level and for the two-digit room code would be enough for the levels (1-9 then A-Z giving me 35 levels) and for the rooms (Room 34, Room A9, Room ZD, etc. giving me something over 1,000 rooms per level).

I keyed about a third of the rooms on Level 1 and a quarter of Level 2 and 3 each. It was important to me that there be empty spaces between exciting adventure rooms. I mapped but did not key in about half of Level 4 and small parts of Level 5. But I had plenty of room descriptions that I wanted to put there eventually.

So why did it abruptly stop? It was every other weekend swapping with another campaign, some players could only play every other week, and they wanted to play in the other one. Partly because I was running it as a playtest of an earlier version of Game XYZ and they didn’t enjoy it as much.

(It was entirely feat-based, classes gaining a feat every level, but almost all feats could be taken up to 5 times for broader and more intense effect)

So lesson learned! Make a simple playtest module and let them concentrate on the system for a couple sessions instead of the adventure. Not a dungeon with 60 pages of terse 10-point text for Level 1.

Tags: D&D, Maps, Megadungeon, Undermountain