Mapping that Megadungeon

At first, the prospect of mapping a Megadungeon can seem like an extrememly daunting one. Megadungeons are typically considered to be a minimum of 5 or 10 levels, and sometimes even more. Factor in that there can be hundreds of rooms on each level, and the task quickly begins to look insurmountable.

Obviously, one "fix" a lot of DMs take is simply to make the dungeon smaller. Say, 30 or 40 rooms per level, thereby making the mapping a bit more manageable. But then, its not really a Megadungeon anymore.

The best way I've found to manage that heavy mapping load is simply to change your perspective on what exactly needs to be mapped. Most DMs I've spoken with running Megadungeons will tell you that they're running it about 33% pre-planned, 33% random charts, and the remaining 34% "on-the-fly". Why?

Because that's the way we run most Campaign Settings.

The Megadungeon isn't a tournament module, where every 5' step needs to be carefully planned out. It isn't even a normal adventure, where most stuff is planned out, with a wandering monster table thrown in for good measure. Megadungeons are living, breathing, Campaign Settings. They change, sometimes from session to session. They are ultimately indefinable, as extensions of the Mythical Underworld. They are necessarily mutable, as the best and most memorable Megadungeons are influenced by the whims and wants of the players in the campaign.

Map your Megadungeon the same way you would your campaign setting. Start with a familiar "home town" area they're going to frequent. In most cases, this is the main entrance to the dungeon and the main connection points. Sketch out a rough idea of the scope of the campaign setting, er Megadungeon. Then add detail as you need it, and as the characters journey. Map possible areas of further exploration a little at a time, in between sessions, so that mapping goes back to being a fun, relaxing pasttime, rather than a chore.

There are only two parts of the Megadungeon that should be even remotely set in stone (ahem;):

1. Where the players have already been. They're going to be mapping it too, so don't be too cruel and change everything every time they walk through the caverns on level four. Try and keep things fairly constant where the players have already been, and if you do change something in that area, make it for a good anf fun reason, like giving them a mystery to solve. It can be a good idea to collect the players' map at the end of every session, especially if they've ventured off into an area you havn't fully mapped yet, so you can go ahead and copy their map down on your own "official" one.

2. Places you think are friggin' Cool. Those "iconic" locations within your Megadungeon. The center points in between all those empty rooms filled with wandering monsters and random traps and tricks. The places where you really let your creativity shine as a DM. You don't have to map everything between the Entrance and the Hall of Shattered Thrones anymore than you have to detail everything between Verbobonc and Hommlett unless your players are going to be traveling there sometime soon.

An example map: That roughly rectangular blur above, if you click on it, will enlarge into an early version of the the first three levels (plus two sublevels) of my 10-level Megadungeon, the Forsaken Halls. It serves mainly to detail the "big" locations (with cheesy names to remind me what's there) in the dungeon, and the main connections between the levels. Those crosshatched areas between the big chambers can be interpreted as "dozens of minor rooms, chambers, and caves" and get detailed as needed. For instance, the area on level one that looks like a cross with a star in the middle (The Halls of Madness, as they are known to the players), actually fills an 8"x11" sheet of 8-square-per-inch graph paper and has about a hundred or so rooms. Its been the most extensively explored area of my Megadungeon, and is therefore the most extensively mapped. I have about three sheets of the same size filled in, and a dozen more with just the main areas and connections blown up to the proper scale, waiting to be filled in and detailed as necessary.

By keeping a list of encounters, traps, treasures, and room descriptions handy, I can place these rooms wherever I want, as needed, without being contstrained too heavily by a pre-planned map. The Megadungeon has so far grown organically, and as it has deveolped primarily through play, I can run many sections of it by memory as I run different groups of players through it, adding a little more detail each time as I go. Just like a Campaign Setting. :)