12 June 2025 Underdark Hex Crawl

 12 June 2025 Underdark Hexcrawl

    This is complicated. Since re-discovering Gygax's wilderness hex crawl generator in the DMG from back in the 70s, I've been thinking hard about a few core things related to my gaming activities. First, I realized that I am letting companies and people imagine things for me. I have almost always used modules and campaigns, and while I've personalized them (mixing, matching, changing, adding, subtracting), it is rare that I've actually created something unique. The hex crawl rules have piqued my interest  as far as doing more on my own instead of obsessively buying and collecting. Second, I've been thinking about how to take these hex crawl rules--used for wilderness generation--and apply them to an underdark hex crawl. It has proven to be an extremely complicated endeavor. 

    The under dark is three dimensional, so there is the issue of incline and decline. There are different types of passages (going off of the original underdark module, Descent Into the Depths of the Earth). And there are levels of the underdark (upper, middle, and lower). That's a lot of moving parts. Even if I were to just abstract the three dimensionality of an underdark map, I am left with a large number of variables that have to be accounted for in the creation of any generator. 

For what it's worth, here is my first stab at it.

Passage types: primary (wide and relatively flat), secondary (narrower, less ease of travel, descending), and tertiary (narrow, steep, hazardous). 

Areas: rubble, running water, stagnant water, sinkholes, crevasses, fungal forests, large/medium/small cavern(s), lairs, ruins, stalactite/stalagmite forests, cave in, lemon squeeze/choke points, settlement (with various sizes). 

If each hex is a passage type, how do I determine how many other passages entries there are in each hex, and of what type? And how do you move from one passage type to another? I can picture a 3-D map in my head pretty easily, but I am working in two dimensions on a piece of graph paper. [Solution: table for each hex determining how many, and what kind, of passages exist in the hex. But what about direction?]

So let's say we are working in a primary passage hex square that represents one mile. When the characters move to the next hex (and how many options will there be? They are underground and surrounded by solid rock!) how to I determine...

Thought: each hex has an option for each kind of tunnel, and player decisions determine what kind of passage they will enter when they leave the hex. They will create the next hex by choosing the passage type. I'd need a table for each kind of passage. Can you go from primary to tertiary without secondary? Probably not, right? So primary only leads to secondary, and secondary allows for both primary or tertiary as options. Tertiary only allows for the choice of secondary. 

Similarly, a primary passage is upperdark, a secondary passage is middle dark, and a tertiary passage is lowerdark. Distance would have be abstracted (i.e. 'this passage descends quickly)

Question: If you went from a primary to a secondary, then back to a primary...is it the same tunnel? How would that look on a map? 

Question: d10, d12, d20? 

So each hex is a one mile passage with one kind of feature and multiple (maybe) other passages. 

Rough draft