Digital Mapping Workshop for Gamers

Jürgen Hubert

aka "Herr Doktor Hubert"
Validated User
As an expansion of a thread over on the d20 forum, I think it might be useful if we started a thread where we can talk shop about creating digital maps for our games - I have my techniques from which others can learn, and I am sure others have their own techniques which I will find at least equally interesting. And for those curious about any aspect of the mapmaking art, don't hesitate to ask! The central message I want to convey is: While mapmaking (digital or otherwise) requires some effort, it is not that hard, and can be very rewarding even with modest skill.

So let's start with one of the fundamental questions: Why do digital mapmaking at all - as opposed to traditional mapmaking with pencils and the like? Many would point to the ability of graphics software to cleanly reverse any (recent) edits, and I certainly wouldn't disagree that this is unimportant. However, for me the one thing that makes the most difference is this: Layers!

Layers are your friends!

Pretty much any graphics software has these, and they are really very fundamental to any graphical design on the computer. Imagine these as a stack of transparent sheets on top of each other - and you can draw on each of these sheets individually without affecting any of the other sheets. Thus, you could use one layer for (say) drawing coastlines, another for roads, a third one for forests and so forth - and you can edit each of these individually, without affecting the others. Thus, when you realize you want to edit some small aspect of the map, you don't have to erase everything else you drew nearby. This makes a huge, huge difference in how you can work, and it is an enormous timesaver.

The "default assumption" for layers is that anything drawn on a "higher" layer (you can, of course, shuffle layers around) will completely cover anything drawn on a "lower" layer. There are a few ways to circumvent this. For example, you could make the lines you draw on higher layers semi-transparent (the "opacity" of the brush), or you could make the layer itself semi-transparent (by altering the opacity of the entire layer) - for example, if you set the opacity to 50%, you will still see what is on the lower layer beneath your drawings - but at only 50% of the visibility as if it was unobstructed.

Or you could switch the layer to a different "layer mode". The most common of these modes (and pretty much the only one I ever use) is "Multiply", which multiplies the brightness of the colors on the lower layers with the brightness of the colors on the higher level. "Black" should be seen as a multiplication value of 0 - i.e. anything below a black line on a Multiply layer will also be rendered black. "White", on the other hand, counts as a multiplier of "1", so everything below it will be absolutely unaffected. If you are curious, this also works for the three primary colors used in graphics software - that is, "Red", "Green", or "Blue". So if you want to turn the entire map red for some reason, you can fill the Multiply layer with the color Red. This means that all "Red" color values get the multiplier 1, while all "Green" or "Blue" color values get the multiplier 0 - in other words, they vanish (it's more likely that you want to give the map sepia tones, though...).

As a typical example, let's say that you have a conventional overland map and want to put a hex overlay over it for your hexcrawl game. Thus, you create a Multiply layer and either draw a hex grid over it (this is doing it the hard way) or you import a hex grid from elsewhere into this layer (more on that later). Possibilities include:

- You want the hex grid to be strong and prominent: You leave the lines black and set the Multiply value to 100%
- You want the hex grid to be visible, but somewhat subtle: You either pick a light grey value or set the Multiply value of the layer to 50% or less.

And remember, if you want to edit the map later on you can do so - while leaving the hex grid completely unaffected. You can also make layers visible or invisible - for example, one layer could be the "Player's Map" with locations the PCs know about, while another is the "GM's map" with locations only you know about, which means you don't have to redraw the same map for your players!

Really, the uses for layers are practically endless. Learn to use them, and you know the most important tool for creating digital maps.

Jürgen Hubert

aka "Herr Doktor Hubert"
Validated User
The next question is: "What tools do you need for digital mapmaking?" The good news is that as long as you have a PC, the rest is fairly affordable.

First, you need a bitmap-based graphics program. "Bitmap-based" means that you manipulate the individual pixels of an image (such as those a typical jpeg or png file consists of). I used GIMP frequently, but these days I tend to favor krita, which is awesome - especially once you download and install all the brushes. If you have commercial software like Photoshop or Painter, then that's nice - but you don't need them.

Second, you will need a vector-based graphics program. Unlike bitmap-based programs, these do not manipulate individual pixels. Instead, they define lines, circles, and other shapes via vectors and angles. This makes them more complex to draw with, but their big advantage is that you can zoom with them at any scale, and the lines will still stay sharp. Not that my approach actually requires drawing with them - instead I use them to organize and scale maps, for which they are extremely useful (more on that later). I personally use Inkscape, which is also free. CorelDraw is the commercial equivalent, but for my purposes it is not needed.

Finally, you should get a graphics tablet - and that is, sadly, where you have to invest some money. For those starting out, I recommend getting the cheapest Wacom brand tablet out there - a Bamboo, which can be had for 70 American bucks or so:

These have a drawing area on which you can move a "pen" - and when you move the pen, your mouse pointer will move on the screen with it. If you press it down, it works like a click of the mouse. Furthermore, such tablets have pressure sensitivity, which means that it measures how hard you press the pen against the surface - and most bitmap-based graphics programs make use of this feature by allowing you to affect the size, opacity, or even color or other effects of your digital brush (more advanced models also have tilt sensitivity, which is neat but you probably don't need it. Even more advanced models have built-in screens which you probably do want because this is awesome, but which is probably beyond your budget right now. I got one, for the record - but I worked for years with a simpler tablet, and thus it should work for you as well).

Using a graphics tablet with a pen is much more natural for drawing than using a mouse - and much, much faster. There will be a bit of a "disconnect" because unlike with normal drawing you will need to watch the screen while moving your hand, but you should soon get used to it.

This is it for the basics - any questions so far?

Jürgen Hubert

aka "Herr Doktor Hubert"
Validated User
Let's start with Inkscape. I've said that you can use it to organize your maps, in particular overland maps. Let's consider a typical scenario: You use a pre-existing campaign setting, and want to draw a new map of a particular area. This is the case for me - I want to draw a new map of the "Maztica" sub-setting from the Forgotten Realms.

I have various map fragments to start with. For starters, the map from the PDF version of the Maztica Boxed Set is split into 16 individual pages. The adventures "Endless Armies" and "City of Gold" likewise have further regional maps. Finally, I also have the Forgotten Realms world map that used to be part of the Interactive Atlas and which still floats around on the web, which gives me rough outlines of regions beyond the core lands of Maztica.

I started with importing all of the map fragments from the Maztica Boxed Set and arranged them into the proper order so that they represent one continuous map. Then I selected them all and made a "group" out of them, so that I could move and scale them as one "item" later on. I subsequently imported the other maps to other layers. Then I started moving the various maps on the different layers around and changing their scale until they roughly fit together (as you will learn, such maps will rarely fit together perfectly...). Finally, I added one more layer and put down some markers on places where I wanted to put new locations later on. The result looks something like this:

Spoiler: Show

And now I can export the whole image or a part of it at the image resolution I want to the bitmap-based graphics program I want, put it on a separate layer, and just paint over this image on a different layer - using the outlines of shores, mountains, forests and so on from the original maps but making it my own. And once I have drawn a new map, I can just re-import it into Inkscape using the same technique and using it as a base for different regional maps I want to draw later on.
Last edited:

Jürgen Hubert

aka "Herr Doktor Hubert"
Validated User
Yeah, I don't use Inkscape for drawing either. I do use GIPM for making bitmap layers transparent - since it started out as an open source project for building something similar as Photoshop, this makes sense.

Its brushes are very limited though - and that's where krita excels.

Jürgen Hubert

aka "Herr Doktor Hubert"
Validated User
Another neat trick for Inkscape: How to use grid overlays. This is all-important for turning normal maps into hexcrawl maps, but it works for square grids (likely for combat encounter maps) just as well.

First, get yourself a hex grid - in SVG ("scaleable vector graphics") format, which is the native Inkscape format. Remember what I said about vector graphics? These hex grids will have sharp lines no matter at what resolution you use them - no "anti-aliasing" effect. There are plenty of SVG hex grids out on the web, and there are even tutorials on how to make your own - just google for it. Ideally, you will want a hexgrid with the precise number of hexes that you want to use for your detail map.

Let's assume that you start with an existing map - in my case, it was the map of Exalted's world of Creation (using the 3E version as a base). First, we need to establish the map scale we want to use. I wanted to have a 25 mile square, and the map (which covered the entire world) had no smaller visible scale than 500 miles.

First, I imported the map of Creation into Inkscape. Then I imported a hex grid of the "standard" size I wanted to use (11x8 hexes, in my case) on a separate layer, rotated it by 90 degrees, and then copied it and added the copy so that it fit in tightly with the first grid. Then I turned the two grids into a "group", which allowed me to change both their sizes at the same time. Then I changed the scale until I had the scale I needed - 20 hexes with 25 miles each covering the 500 miles of the map scale:

Then I ungrouped the two grids and copied one and rotated it back by 90 degrees. This gave me my "standard grid" which I copied and pasted until it covered the region I wanted to detail - in this case, the land of An-Teng:

Remember what I said about using Inkscape to organize your maps? As you can see, I also used a regional map from an earlier edition of Exalted and put it approximately where it fit on the larger world map - thus giving me more details I could work with.

Then I selected the single "standard hex grid" that covered the region I wanted to develop in detail. Then I used the "Export Bitmap" function of Inkscape to export only that particular selection, choosing a resolution I wanted to use in a bitmap graphics program.

I then imported the bitmap into that program as a layer and also imported the empty "standard grid" into a separate layer, using the same resolution. I "drew over" the former bitmap and added further details, but left the empty hex grid on its own layer (set to "multiply", as described earlier). Eventually, I could simply discard the first bitmap and use my own map instead:

Once you have finished with that first map element, you can re-import it to Inkscape and start working on adjourning areas. Here is an example from a different campaign:

As you can see, the process might require a bit of work - but it's not really difficult.


Surely you jest, Mr Fred
RPGnet Member
Validated User
This video series gives some good advice for fantasy cartographing.

Will also keep tabs on thsi thread. :)


Jürgen Hubert

aka "Herr Doktor Hubert"
Validated User
This video series gives some good advice for fantasy cartographing.
This video series use Photoshop, which probably not everyone is going to have, but some of the techniques should be applicable to other software. GIMP, in particular, has a bunch of Photoshop-esque filters, though nowhere near the same variety as Photoshop.

In the beginning the series spends a lot of time with creating a "parchment map" background, which is not something I would recommend for beginners. Start with some functional maps first and master outlines before you get fancy. The later segments are probably more useful for newbies.

Cloud Divider

Registered User
Validated User
So, in this modern age of connected gamers, I've taken to using cloud-based applications to share maps to the group during gameplay. It allows me to provide dynamic maps, updates as the situation changes (PC and opposition locations, etc).

When I've had overhead projectors available, I've projected the maps onto a nearby wall, but even just having the players pull the maps on their phones works well enough. It also saves valuable table space over a big vinyl map or whatever, which we use for munchies.

I have been using Google's attached apps - primarily Slides (because it allows me to stack related maps together - a regional map, a city map, detail map of a city block, and a floor plan of the target building). It works, though is sometimes sub-optimal (it doesn't handle layers well, and it's a beast to try and measure scale conveniently). For modern / SciFi, it works because I can rely on simple geometric primitives (squares, rectangles) for most map features.

They're not pretty - though generally better than what I used to do with sketched maps on scratch paper.

If anyone wants to see, I can share out the maps I've been using for a recent story arc.

Are there any better options for some of these applications?
Top Bottom