|I can show you the world...|
As usual, please check out the source of inspiration for this series, as well as the rest of the articles I've posted.
Today we're going to instantly build worlds, and that's kind of wild. What sort of game would require an entire world to be generated on-the-fly?
Well, for one, Sci-fi games. When you're hopping from world to world, it's good to have the ability to generate a lot of terrain between sessions.
But the same can be said for fantasy games in certain situations. What if your players discover a map of the world, and you haven't created anything like it yet? What if there's a massive magical event where the structure of the world shifts? What if the characters want to go to the moon and look down at the world? What if they step into another plane, where there's a new world to discover? Or even, what if they want to know how close the nearest volcano is so they can throw a magic ring into it?
Welcome to instant worldbuilding!
Instant Settlement: World
So, for this set, we'll roll a pool of dice, as usual. But this time, we aren't going to have a variety of dice types. That's because this system uses a single, basic idea to create landmasses: tectonic plates.
Similar to our country and cave rolls, the dice will form triangles. Those will represent the various tectonic plates that form the crust of the planet. The numbers on the dice will determine their relative elevation, as well as the motion that occurs between them.
The dice pool will consist of just d20s, and I'd recommend 8-10 of them for a whole world map. You could do as few as 5 or 6 if you just want to determine the contents of a single hemisphere, but I wouldn't recommend going lower than that.
Next, connect them with triangles, as usual.
Next up, we'll put numbers in there, but instead of just putting numbers within the triangles, we'll also put them on each line. So, the triangles will have 3 d20s and each line will have 2.
Each triangle represents a tectonic plate, and each line represents a fault line. The total of the 3 d20s determines the elevation of the plate, and the total of the line determines the activity found along that fault.
Now, we get to the biggest choice of the world: What is the sea level?
Depending on the game, you could set the sea level anywhere. For a planet-hopping game or post-apocalyptic game, it's totally reasonable to set the sea level super-high or super-low.
However, in a standard fantasy game that involves the players living, exploring, and dying on a single world, you'll probably want to go somewhere in the middle. Based on the percentages of die results from 3d20s, here are my recommendations:
- Desert World (less than 1% water): sea level 55
- Dry World (about 10% water): sea level 45
- Temperate World (about 50% water): sea level 30
- Wet World (about 75% water, like Earth): sea level 20
- Ocean World (less than 1% land): sea level 10
If a plate is lower than or equal to sea level, it's considered an oceanic plate. If it's higher than sea level, it's considered a continental plate.
This part will take some adjustment. My roll was kind of higher than average. That's fine for a one-shot world, but if I want to make this a permanent setting, I'd need to set up my sea level to get the type of variety I want.
Here's the roll above, blocked out into oceanic/continental plates, at sea level 30:
That's a lot of land. Globewise, you could imagine this as two land-based poles connected by a large strip of land, with the ocean wrapping around the other half of the globe. I'm not too keen on it... especially since I know my roll was a little higher than average.
Here's the same plates as least time, blocked out at sea level 40. This might seem like too much ocean, but I actually prefer it. The Earth is 70% ocean, after all.
Putting space between landmasses also gives the world an opportunity to grow in divergent ways. In the first world, a conqueror would eventually take over most of the world, and the entire planet would have this shared point in history where they were all subjected to a single culture. I'd rather have that as a possibility in some parts of the world, but not all. having a large ocean limits the effects of the Ghengis Khans and Alexander the Greats of the world.
Next up, let's fill in our landmasses and make things more interesting. Here's the guide I used for building islands and seas within the world:
- Sea Level -10 or lower: deep ocean, 1 or 2 small islands (oceanic plate)
- Example: Pacific Ocean/Hawaii
- Sea Level -5 to -9: ocean, a small island country or two (oceanic plate)
- Example: The Caribbean, Japan
- Sea Level 0 to -4: Oceania, a few island countries and many small islands (oceanic plate)
- Example: Great Britain, Indonesia
- Sea Level +1 to +4: low countries (continental plate)
- Example: India, Southern Europe, Central America
- Sea Level +5 to +9: hilly countries (continental plate)
- Example: North America, Northern Europe, Africa
- Sea Level +10 or higher: mountainous countries (continental plate)
- Example: Eurasia, South America
With that in mind, let's bring in some islands and make the coasts more interesting. I use the Jared Blando- approved method of making coastlines: start with a single line, then make a wiggly line on top of it. Very effective.
Notice I also added forests around the equator and ice around the poles. Again, this is a decision you'll have to make for your world. I wanted a world with variety of ecosystems, but if you want to make an ice world, move the ice caps further towards the equator. If you want to make a jungle world, move the forests out towards the poles.
I also added mountain ranges. However, according to my own method, I didn't have any plates that were at 50+, so I shouldn't have had any mountainous plates. But just because there are no mountainous plates doesn't mean there aren't any mountain ranges! How did I determine where the mountain ranges were?
Simple: fault lines! Remember those?
Each line has a number on it. Though these are somewhat correlated to plate elevation, they can also contribute to cool landscape features. Using the number assigned to each line, we can determine the behavior of each fault line.
- 2-14: Transform Boundary (plates move past each other, rubbing as opposed to pushing/pulling)
- Contains hills and flatlands, lots of earthquakes. If one of these happens to land on a coast, you'll get a California situation where there are notorious earthquakes.
- 15-27: Convergent Boundary (plates push into each other)
- If both are continental plates, they push upwards and form a large mountain range
- If one plate is oceanic and one is continental, the oceanic plate is pushed under the continental plate and forms an offshore oceanic trench, usually replete with volcanoes
- If both plates are oceanic, they push upwards and make underwater volcanoes, which will eventually form the site of future islands
- 28-40: Divergent Boundary (plates pull apart)
- Contains valleys or oceanic rifts, depending on the severity of the plate distance, this could lead to volcanoes.
Here's my map with the seismic activity included. Red is where volcanoes can be found, and grey indicates earthquakes. Note the western edge of the northern large continent has a transform fault running not far from it, creating a hot spot for earthquakes.
Finally, you can use the country generator to build countries, which will help define the coastlines. Or, just assume that major cities will be found along the coast.
Well, that's it! The entire world can now be randomly generated! I hope this was a fun and useful exercise, even if it was just a thought experiment and you don't ever plan to use this stuff.
Thanks for reading!