Treating dungeons as separate and normally-mapped locations, would you use a hex map for the Underdark? Why or why not? What are things that should be considered when doing so?

Don't know if hex crawl can be done.  To map the underdark you have to think of the third dimension.  A proper underdark map would need a x, y, and z axis.

If the underdark is a truly vast domain then I would treat it much like above ground maps.

Like any other map, a series done in several different scales can help keep proportions in perspective.

Start with a really rough outline at the same hex scale as your continent map. On this map will be major cavern systems and tunnels, and secondary passages that feed into the major systems. You can note the average depth below the surface for each major portion. Very little detail is needed here, just enough to eyeball what systems run where and the basic distance of travel for a group entering the system from one city and emerging from another.

From there you can create more detailed maps at a smaller scale as needed, much like you would with a region above ground that will be the setting of actual adventures. Choose whatever portion of your large scale rough map that you intend to detail and blow up those parts with more detailed maps. These will show major and minor passages, perhaps some tertiary tunnels too small to bother with on the larger scale map, any civilizations or lairs which would be much like villages & towns on an outdoor map. The scale of this first secondary map depends on how much of the large scale map it is intended to cover. Just as with outdoor maps, if the exploration area is fairly large perhaps 6 miles per hex is a good start.

Beyond that you can tighten the focus even more and make more detailed 1 mile/hex maps showing the same sort of things on a larger scale. You can map out as much level as detail as you feel like, going as far as a combat grid scale for areas that might see heavy action.

Quote from: Shipyard Locked;787277Treating dungeons as separate and normally-mapped locations, would you use a hex map for the Underdark? Why or why not? What are things that should be considered when doing so?

What does an old-school D series hex map buy you except a way to exactly map large distances? Do you really need that? I am staring a 5E campaign set in Menzzoberranzan and I briefly considered hex maps for the area around the city but I quickly decided they weren't aesthetically pleasing and not really that useful to me...

Quote from: Snowman0147;787279Don't know if hex crawl can be done.  To map the underdark you have to think of the third dimension.  A proper underdark map would need a x, y, and z axis.

True.

A computer program allowing overlays, side views, etc would help make it happen.

It would not be that different than old "hex maps" for the Warden for Metamorphosis where you explored various levels of the giant spacecraft.

I don't think I have any mapping cred, but that obviously won't stop me from sharing my from the hip opinion. It seems to me the inaccessible space in an underdark environment would be be so relatively high that a proper hex map wouldn't be very useful at a high level. My instinct would be to go with a connectivity driven graph style map, and then evaluate whether a hex style map would make sense at higher resolution.

A map of the underdark is all pro, no con. It has always been the ultimate dungeon exploration environment. The presence of the underdark is what gives Moria some balls. It is what makes the GDQ module series a classic. The Underdark boxed set is one of the most ambitious, funnest settings for 2E. So, I'm all for it.

The main thing is to get your mapping skills to a level where they depict what is in your imagination. I recommend you spend some time looking at maps of large natural cave systems. They are orders of magnitude smaller than what you have in mind, but topologically rich, and a good source for material you can use as starter seeds. I have a tremendous map of a cave system in South Dakota that I use for gaming all the time. It is as 3D and zany as you can imagine, but it all works in a 2D representation, provided you understand the rules behind the graphic design.

Quote from: Larsdangly;787304The Underdark boxed set is one of the most ambitious, funnest settings for 2E.

Do you mean the Menzoberranzan boxed set? Or something else?

The Ranger in our party has Underdark as his favored land (5e).  This gives him a variety of long distance exploration and travel abilities, that just work better with a hex based map system.  So, I am thinking of doing this for the underdark.

I like the idea (D1-3!) but one factor is how you intend to play out travel and movement in the underdark.  Huge caverns are wilderness for all intents and purposes, perhaps other than weather.  But what about huge labyrinthine structure, like zones of porous rock that has been eroded into a maze-like warrens - miles on a side?

You can treat these like forests, where they can be navigated abstractly just with hideous strategic movement penalties ("You work your way through the maze-like warrens for three days.")

If, on the other hand, you're talking through each turn, then a hex map makes less sense to me, and a point crawl with detailed maps of tricky areas seems more appropriate.

For whatever reason I've always thought of the Underdark as a bit of a dreamland/fairyland... not altogether fixed and mappable... not by conventional means at least. It's not JUST a bunch of caverns.
If I were creating a PC who wanted to claim familiarity with it... be able to find his way around in it... I'd draw some inspiration from the movie Stalker... where the guide is strangely in tune with the environment and its dangers and knows that the shortest path is usually not the best one. Getting around is as much an act of divination as it is navigation.
There'd be some safe/stable passages... main thoroughfares... but stepping off the path is always risky... even if it's only a few feet.

Quote from: Mistwell;787315The Ranger in our party has Underdark as his favored land (5e).  This gives him a variety of long distance exploration and travel abilities, that just work better with a hex based map system.  So, I am thinking of doing this for the underdark.

This is exactly why I'm considering a hex map. Because I'm using the city of Dar Jin in Eberron as my home base (foreign access to the interior is very restricted) the other wilderness options are somewhat limited.

Quote from: Snowman0147To map the underdark you have to think of the third dimension. A proper underdark map would need a x, y, and z axis.

True, but if you're trying to keep travel through the Underdark abstract, then it seems a bit excessive for the same reasons most miniature-based space battle games just abstract to a two dimensional tabletop. I'd go for maybe one or two extra "levels" with only a few bridge hexes if I had the time. Otherwise, to keep the flavor I would just describe the journey through an individual Underdark hex has having a lot of vertical passages and loops that go under/over themselves without actually changing levels.

Quote from: fuseboyBut what about huge labyrinthine structure, like zones of porous rock that has been eroded into a maze-like warrens - miles on a side?

You can treat these like forests, where they can be navigated abstractly just with hideous strategic movement penalties ("You work your way through the maze-like warrens for three days.")

I think the forest comparison is the best way of putting it. Some forests are really confusing to navigate!

Quote from: Shipyard Locked;787277Treating dungeons as separate and normally-mapped locations, would you use a hex map for the Underdark? Why or why not? What are things that should be considered when doing so?

I've played around with this idea for many years. Never actually run the Underdark with a hex map, but I am currently running a huge technological complex in Numenera with a hex map that shares a lot of similarities to the Underdark.

Three key points:

(1) What makes a hex map work is that it abstracts the actual terrain. If you're doing a wilderness hex map, you shouldn't try to map every tree... or even every single country lane. If you do that, you're defeating the entire point of the hex map. Similarly, if you're designing your Underdark with a hex map you should not be trying to map every individual tunnel. (You might map major thoroughfares, the same way that major highways or rivers would be indicated on your wilderness hex map.)

(2) One key distinction between a wilderness hex map and an Underdark hex map is that, generally speaking, travel is always assumed to be possible through the side of a wilderness hex. Not necessarily the case in the Underdark and so one thing you'll want to develop is a key indicating at least three states: Open (there are lots of tunnels leading from this hex to that hex), Closed (there are no tunnels leading from this hex to that hex), and Chokepoint (you can get from this hex to that hex, but only by passing through a specific keyed location; a given chokepoint could also be a secret that needs to be discovered).

(3) The industry has developed a fairly standard "vocabulary" of wilderness terrain types. (These actually predate D&D and were inherited from Outdoor Survival.) IMO, you're going to want to develop a similarly interesting vocabulary of at least 4-5 different Underdark terrain types. This is to make the map more interesting, but also to help contextualize the PCs as they explore/navigate the Underdark.

The points others are making about the three-dimensional nature of the Underdark are also important to take into consideration. (Of course, that's going to be true no matter how you map your Underdark.)

Quote from: Simlasa;787320For whatever reason I've always thought of the Underdark as a bit of a dreamland/fairyland... not altogether fixed and mappable... not by conventional means at least. It's not JUST a bunch of caverns.
If I were creating a PC who wanted to claim familiarity with it... be able to find his way around in it... I'd draw some inspiration from the movie Stalker... where the guide is strangely in tune with the environment and its dangers and knows that the shortest path is usually not the best one. Getting around is as much an act of divination as it is navigation.
There'd be some safe/stable passages... main thoroughfares... but stepping off the path is always risky... even if it's only a few feet.

I like your take on it. I'm not generally one for the dungeon as mythic underworld, ala Philotomy Jurament, but the Underdark as mythic underworld I can definitely get behind.

Quote from: Justin Alexander;787384I've played around with this idea for many years.

Excellent post, Justin.