Thursday, June 14, 2018

Mapmaking: Path Cartograms

A Path Cartogram is a map for when the Adventurers must find a way through a vast place, searching for something hidden in the geography. It's for terrain that's untamed because it's not tamable. Places wisely left alone, even if they're found near friendlier terrain.

An ancient forest where the sun is dimmed by the trees, a grassland crammed with unascended hills, a stretch of barren wasteland filled with rolling dust and tremendous rocks.

A range of tooth-looking mountains with deep hidden valleys, an oppressively humid swamp that no one ever crosses.

Adventures have a reason to go in, they might seek a hidden treasure. The old stone dolmen where you can meet the Mother of the Woods. A burial mound, where you can find the weapons of the sacred dead. The "nostril of God", a vast cavern leading to the world's hollow core.

The journey itself might be the goal. There is no other way to reach the plateau of azure grass. The fungus that raises the dead sprouts somewhere deep in that place, nowhere else. This is the only place no one has searched for the lost scholars.

A Path Cartogram is for depicting an exploration over a long time, an expedition. It's a way to make preparing that kind of Adventure easier, and without you needing to become an expert cartographer. Once it's been explored you're left with a kind of mapped outdoor dungeon.

The game doesn't need an accurately mapped out world to be played, since the Adventurers aren't going to be surveyors. It just needs one that's ready to be discovered.

A Path Cartogram lays out some probabilities in a spatial sense, tells you what the Adventurers find as they explore an area, and creates a diagram that makes the place "real" once they're done.

It reveals a dungeon-like environment from the natural world as its used.

It's also Referee's tool, like a dungeon map. You don't show it to the players.

As Referee you'll describe the place before them in some general sweeping terms, and then they'll tell you which direction they go in. You roll some dice, tell them what they see, what they find, and what happens. Time passes, things are encountered. Places are discovered. You all see how it all unfolds.

A Cartogram represents a difficult example of a specific kind of environmental "place". The best term for this is an ecoregion. Ecoregions are places that share a large amount species, ecological dynamics, and conditions over a large area. There are more than 800 of them in our world, here's a good list. Although it's not exactly the right word, I'm going to use the word biome instead of "ecozone" going forward.

Remember, a Cartogram is for the especially difficult part of the rain forest, even if the whole region of your campaign is in and around the rain forest. The Cartogram is the part without roads, the part no one visits. You don't need to use one for every instance of this biome in your world.

Here's what a very simple Cartogram looks like before anything happens on it.

You can see that this looks a bit like a hex-crawl or the usual graph paper map, but it's not.

I use graph paper instead of hexes because no one has hex paper handy and squares are easier to draw. This also isn't a scaled map of a territory like a hex map or grid is.

Everything that's been outlined is the zone this Cartogram is about.

The base unit of the Cartogram is the blank square. Marking a square makes it into something else, so a blank square doesn't represent anything besides a potential something on the Cartogram.

You can't know anything about what's in a square without going through it. You can't "see" into it, like with a hex crawl. You'll have an idea of things (like mountains far away), and that it's part of this general ecoregion, but that's it.

Each of those groups of squares outlined in black is a region. All the regions together is the zone the Adventurers are going to explore.

The lines marking a region don't represent a barrier, or prevent movement. Regions are all still all the same biome, but there might be variations among them. Some areas could be more steep or flatter or a bit denser or sparser or whatever, but it's all still distinctly one particular kind of "place".  

Let's say our Cartogram is an old-growth forest. All regions would be filled with big trees, some still growing, some dead and standing. There are layers of tree canopy above, and a mess of wooden debris on the forest floor. There are smaller, newer trees growing up between the old ones, old stumps covered in fungus, pits and mounds formed when great trees fell. The rich soil is covered in mosses and ferns. It's temperate with regular rain, there will be streams, waterfalls, lakes. There are probably owls.

Outside of the regions the environment is different somehow. In narrative terms it could be a different biome (what you'd call an ecotone), or a milder version of the same biome as the zone.

In game terms this just means you'll handle things differently outside of the Cartogram if and when the Adventurers leave it. To put it another way a Cartogram is a dungeon: all the monsters and treasure are inside it, outside it's safe and boring with roads and towns.

For the old-growth forest this could be a gradual change into grassland caused by inferior soil, or a treeline caused by going higher up into the atmosphere where less can grow.

The thick grey line along the outside edge of some regions is where there is a barrier.

A barrier stops movement, it means you have to change directions.

The foot of a mountain no human could climb, the edge of some unbelievable canyon, an actual fucking river of boiling magma. You can't cross a barrier without extraordinary means, like flight. If Adventurers move into a barrier square they change direction.

Remember, Adventurers don’t "see" across the map enough to know what’s coming. Information is only gathered through travel.

In our old growth forest let's say the barrier is an impossibly steep mountain range. You would be aware of those mountains existing while you traveled, and of getting closer to them if you went in their direction, but you won't know when those mountains become a problem until you got to that exact square marked as a barrier on the Cartogram. 

Edges without a barrier are a just a porous border, beyond them is that transition into just regular wasteland, or whatever. If you cross the border onto the outside you can change directions, or you have the option to "step outside".

The red circle is a trailhead. This is the place where the journey begins, a last sunny meadow before the woods become cursed, or the tiny canyon leading into the rocky valley of tremendous arachnids.

The final cabin before the cliffs of green stone, that village of idiots at the edge of civilization, or some kind of other landmark like a miraculous oasis before the desert of the centipedes. It can also be a place where the journey ends, a stopping place of note, if it's discovered.

Our trailhead is a a campsite just a few dozen yards from the first indisputably massive ancient tree, at the edge of a sparser, less mystical woodland.

That red letter A is the locus. A locus is a goal, or endpoint. This is a very special place. It's important and distinct, and if it's the only one on the map it's probably the only reason you came here, it's the thing you're looking for. Finding a locus is just a matter of traveling to the square that designates it.

In our old growth forest we're trying to find the largest of all the ancient trees. It's been dead for centuries, and in it's hollow lives an immense white owl that is either a dreadful predator of women and men or an embodiment of nature with which we shall commune. Perhaps both.

Every Cartogram has an 8 point compass on it. Movement in all cardinal directions is possible, and must be recorded by the Referee. You'll want to draw a copy for the players (since they should be drawing a map for themselves), since North is typically pointing in an odd direction.

Here's a Cartogram after some movement has happened.

At a trailhead you can see what directions across adjacent squares lead into the zone, but nothing else.

So from this trailhead you can see that going W, NW, or N will take you into the zone. 

Adventurers make their first move by saying what direction they go in. The Referee then rolls a movement die, and draws a line leading from the trailhead to the center of the square that far away. (e.g., if a 1 was rolled they'd mark the center of an adjacent square, if a 2 "adjacent and a half", etc.).

The line is a trail, and a trail is formed whenever the Adventurers move. Trails are generally in one cardinal direction, but there are exceptions.

A dot is marked in the center of that square, and then numbered.

All dots are a landmark. A landmark is a spot that's distinct enough from the general environment to function as a sort of marker, but it's not special enough to be a locus.

Landmarks are numbered because they're assigned from a big table or list as they're discovered. In our ancient wood the landmarks so far are:
  • An immense stump 9 feet in diameter, covered in tiny scarlet mushrooms that dimly glow in the night. 
  • A tree taller than a church steeple, many quiet black birds are nesting in it communally. 
  • A placid pond with contemplative frogs that gaze at us lazily. 
  • A fallen tree at least two meters thick and 40 yards long, it had fallen across a small ravine so we walked beneath it. 
A landmark is found at the end of every trail. A trailhead is a landmark. Any locus, once found, is also a landmark.

After finding a landmark, movement continues in any valid direction, unless the passage of time dictates otherwise.

Trails between landmarks form a path that can be traveled again and again, in each direction.

Starting at the trailhead, this path was formed by going NW, NE, and then NW three more times.

The length of each trail is determined by the Referee with a die roll.

This Cartogram uses a d4. Starting at the trailhead this path was formed by rolling 3, 4, 2, 2, 3.

The length of a trail represents the same approximate amount of time, regardless of length. One day, half a day, a quarter of a day, etc.

We mentioned the passage of time a moment ago, this is where that comes in. On this Cartogram each trail is half a day, so after two trails are made it's time to set up camp and start a fire. In total it took 2 and a half days to reach the locus.

The number rolled for Movement indicates the qualities of the terrain, and from that an (unmeasured) distance can be conveyed.

On a d4: 1 is difficult, while 4 is pleasant. 2 and 3 is "fine", perhaps with some mild inconveniences. It could indicate that the path found was meandering and arduous, or miraculously straight and simple.

So, if you roll a 1 it means that the Adventurers went through some really awful, shitty terrain. In our forest that might be a steep hike, or areas cluttered with woody debris.

They plowed through this until when they finally find a resting place next to a large boulder precariously balanced on the edge of a small cliff.

If you rolled a 4 it meant they just had to high step over some ferns, maybe even with wildflowers and singing birds, until they came to a great tree that was blackened in a lightning strike.

That 2 was when they had to cross that stream with the slippery rocks before they found a fallen tree filled with millions of ants, it looked oily in the dappled sunlight.

A locus is reached when a path touches its square, ending movement immediately.

Play would “zoom in” at this point. You’d describe the wondrous thing they've found, and then use a dungeon map or combat rules or whatever to moderate things, and go back to the Cartogram once everyone leaves.

Here is where the Adventurers found the great owl tree, and possibly became owl pellets or maybe druids. There’s a path leading back if they want to use it, and all the other directions to go in if they want to keep exploring, or to try and see if there's a better way home. If they kept track of the ways they went in terms of the compass they know what directions should work to get them back, too.
If a trail touches a square with an existing landmark it connects to it, and ends movement.

If the Adventurers tried going South they'd discover a pleasant hike between the giant growths (4) towards (a new landmark) this rocky outcropping that resembled a clenched first covered in thick moss, and continued to the Southeast on another nice haunt (another 4), that luckily took them back to that stump with the luminous red fungus in just one day (ending movement). The next morning they'd be able to exit the forest by midday, following that old trail.

Multiple paths in the same direction from a landmark are possible.

If the Adventurers wanted to try a second path east they would have to move away from their first trail. They could make their second by going slightly south or east first (their choice), and then continuing. That would be drawn this way by the referee, if they had rolled a 4 and gone south first.
Additional trails in the same direction incur a penalty, since you must go further and further out to find a fresh way to go.

Even though they rolled a 4, the Adventurers only got that far out because they lose 1 square to moving SW and S, to establish the new trail.

When paths cross each other a real crossroad is formed, and the Adventurers may change direction at no penalty. The distance between two landmarks is always the same.

If you were at landmark 2 you could move to landmark 1, 8, 7, or 3 within a day.

Encountering a barriers or crossing borders subtracts 1 from any remaining movement, and is followed by a change in direction if any movement remains. Mark known barriers and borders with a small notch.

Remember that information is directional on a Cartogram. When you discover a barrier to the Northwest you don't know that it extends to the North and West, or further out on the other squares.

In this universe they went Southwest (rolling a 3) instead, and then found a pair of trees that had fallen into each other, forming a skewed triangle (landmark 5). After this they went Northwest (rolling a 3 again), but then (running into the barrier) discovered the ground became too steep for them to continue in that direction. That night they set up camp at a pond with a lone log bobbing gently inside it. (landmark 6, found there since they lost 1 from their remaining movement by discovering the barrier to the Northwest).

Think of discovering a barrier as going this way. The trail isn't drawn like this because the wasted movement isn't repeated if the path is followed again in the future, but this is why movement is lost that first time.

If they had rolled a 4 they could have continued on in any new direction other than Northwest, like South.

Crossing the outside border of a region works in a similar way, but there's the option of leaving as well as changing directions.

Adventurers might want to occasionally step out of the area to gather supplies or rest: maybe there's no water in the zone, or easier hunting on the outside.

Movement across a border always ends on the first square outside it.

They found a way out to the West (rolling a 1), and decided to use it to step away for a bit. This created a landmark, but it's just their campsite in a clearing of lesser trees (that's why it's not numbered, you don't need these to be that special). In a rare instance of being able to "see", the Adventurers will know there's a possible entrance to the North, Northeast, Southeast, and to the South. They'll find a barrier if they go North, mind you.

Movement ends immediately because the environment outside the zone doesn't need to use these Cartogram mechanics, you might be able to just "go" somewhere once you're outside and all that. If Adventurers want to try and go all around the perimeter of a zone that might be impossible and is at least always mostly fruitless: the whole reason it's a zone is because it's a difficult place you can't learn anything about without going inside.

They could learn that there's a bunch of crags or whatever along the Northeast edge from the outside, sure, but they still won't know when and where that'll matter once they're inside.


Think of a biome of your zone, the various general features of it. Have a locus and a trailhead, and a big list of possible landmarks. Think of the area outside of the zone too. Remember that landmarks can be dirt simple, if you're desperate just make a list of objects and every landmark can be a boulder or two shaped like one of those things. Every Cartogram is an environmental dungeon, so you should have a table of random encounters, even if they're few and far between, as well. Get some graph paper, a few different colors of pencils and pens, and some dice or a random number generator.

The next few choices you make will all bounce off of each other in interesting ways.

number of regions
size of regions
trail time
movement range
rate of encounters

First, how many regions will you have? About twice as many as there would be trails for an ideal journey to the locus seems to work alright, but a lot of the interesting things about a Cartogram happen more frequently on a larger map too. Our example map had 8

Next, how big is each region? Each region is made of a variable number of squares. A minimum of 9 with some dice on top of it works best, with the idea being that whole regions shouldn’t be easy to “skip” due to being tiny. The example had regions that were 9+3d6.

Now, how long is each trail? Combined with the previous two decisions you’ll now get a sense of scale. You can use one day per segment if you want a minor Lewis & Clark expedition to happen, Use half days or quarter days if you want something less grueling. Whatever you choose, remember it’s fixed.

The standard die for determining how many squares get covered per segment is 1d4. This seems right for a simulation of hiking through a dense forest or rocky badlands with mostly stable elevation. If the terrain was really unpredictable, going from near cliffs to plateaus and back again or something, you could use 1d6. If the map was like that and absolutely massive maybe you’d want to use 1d8.

For your random encounters use the trails like you would turns in a standard dungeon. The standard dungeon rate of a 1 in 3 chance of an encounter every 3 turns would be a little sparse. A 1 in 6 chance, or even a 1 in 3, as the Adventurers move along every trail might be better. If there’s going to be frequent camping you might want to have a different encounter roll for during the night, along with different encounters too.

With all that settled, now you can roll dice.

Roll your formula for regions as many times as you need, and then draw them.

You want to draw regions quickly and without thinking too much. The trick with these is that you're creating something using a process, instead of having to design something and be consciously clever. Draw the first one. Draw the next one touching the first one. The ones after that should usually touch at least two other regions.

Follow some rules of thumb: regions are meant to define a big, abstracted space, so they shouldn’t vary too wildly in width or thickness from row to row (adding weird little details will be an option later). They’re also supposed to emulate a naturally formed area, so avoid having perfect squares or rectangles.

You can do the next few things by chance or by design, and in any order you want.

Create a compass. Using 1d8 you can assume 1 is pointing to the top of your graph paper and 5 is pointing to the bottom, and so on. The number you roll is "North". Draw a compass for yourself, and one for the players.
Select a region, then a border square, and place the trailhead just outside it.
select a region and place the locus on a square inside it.
Place barriers around the zone.

There are a lot of ways to randomize barriers, here are a few ideas.

  • draw a barrier clockwise filling a random number of squares after the trailhead, followed by a random number of blank squares, until the trailhead is reached again
  • draw a barrier covering a random number of regions starting with the first region after the trailhead, going clockwise
  • draw a barrier around every region except for a randomly determined number of randomly chosen regions

Don't draw a barrier over a trailhead, or place a trailhead inside a barrier.

Some more ideas to explore:

A very obvious one: there can be more than one trailhead and more than one locus.

You can just mark squares that will be a locus, and use a non-repeating table to find out what they are when they get discovered.

locus list

1. cursed well
2. abandoned cabin
3. yawning cave
4. lucky geyser

If you want a locus or landmark to be easier to discover make it larger on the map.

If you touch any part of that larger locus area you've found it. The circle inside indicates which square all movement into or out is actually based on (movement across the others is free, just curve the trail into the locus). You can also do the same for a trailhead, like if there's some lost city instead of just another great place to build a cabin.

You can make the interior of the zone more restrictive.

Select a region or regions, then draw a barrier over an interior edge of a region, chosen at random.

You can have certain areas designated to have different features (like special encounter tables and whatnot) by coloring them in after selection. Orange has a chance of bears, purple is filled with snakes.

And there you go. There's a lot more than that in terms of options, but I'm testing some things out a bit. I'm using this in my games right now, and I'm very happy with how it's working.

An Adventure built around all this is forthcoming to show you how it all looks together, but this post has gone on long enough.