Maps (part 1): Dungeons, Dragons and ... The Tube

I call this part 1 because there’s almost no way this is the only time I’ll talk about maps. This week I’m talking about D&D, map projections and .

I’m running a Dungeons & Dragons campaign right now, and attempting to make a more complete reference map for it. I’m starting with a digital copy, using an incredible app called Sketches. It’s made me more optimistic about taking up drawing again. I gave up trying at least a decade ago, because something about the idea of “wasting” paper and other materials on practice has always felt particularly discouraging.

I’ve set the adventure in early Song Dynasty China, in what is Hangzhou today. A primary motivation for setting it here is fatigue of fantasy set either in medieval Europe or something approximating it. I also took a year-long Chinese humanities course in college, an entire semester of which was dedicated to this era. The Song lasted 319 years, a period 32% longer than has passed since the signing of the Declaration of Independence. It’s a rich, fantastical period in its own right, with advanced technology (metal movable type printing!) and science (forensics!) and sophisticated art, philosophy and literature.

I keep struggling to balance making the map faithful to the actual geography of the area and convenient for the adventure, which brings me to one of my favorite examples of the tension underlying all data visualization!

My first attempt at a transit map might’ve focused on the geography too, but the origin story of the schematic version feels almost mythical:

Of course! Beck was the perfect convergence of a person who spent all his time in the system, but was also in a position to assess it as such; I think it’s easy as a passenger to interact with infrastructure passively.

It’s also a lovely example of the inescapable tension between translating data into something comprehensible, even beautiful, while staying true to the information itself. This isn’t a perfect analogy because the Tube map is an abstraction of an artificiality, a system about a system, rather than, say, physiological data. But I think of it often as a way to remind myself that there are multiple ways for me to effectively, honestly serve a user (or reader). I just need to understand them.

A perfect example of this is the map projection, ever a lie, but a useful one.

Most of the maps we use online are some variant of the Mercator projection, which I think is the primary or sole projection I saw growing up.

All projections are a compromise because they’re transforming a peculiar ellipsoid – not even a sphere! – into a plane, but Mercator is of a type that exaggerates areas farther from the equator. The following is a lovely diagram made from analyses by Nicolas Auguste Tissot, who used them to account for the type and extent of distortion inherent to a given projection.

There is, of course, a lovely Wikipedia article on map projections organized by surface (cylindrical, conical, etc.) or by preservation of a metric property, if you feel like getting crazy tonight.

There are too many good map phenomena to fit into this issue, but I’d like to mention a few of my favorites here! You may not be surprised that they also follow a sub-theme.

Aaaand here’s a special shout-out to Rachel Binx, whose cartographic art is beautiful and wearable.