Let’s Make a World


A friend was bemoaning the necessity of making a world the other day. Now, since I happen to think that is one of the fun parts of pre-planning a story, I found his reluctance baffling. So I decided to think about how to do such a thing in a methodical fashion.

With my gaming dice.  😀

Now, first and foremost are the plot requirements of the story that’s being planned. They can load the dice at any point, including backing up and rerolling four steps ago.

So let’s start with the big picture.

A star, or stars. Roll a die. Odd number = one star. Even number = two stars. Any more is going to really mess with orbits. I recommend against it, unless you put the third star in a really distant orbit. Although one in a highly eccentric orbit that occasionally causes problems could be useful for plot purposes.
Now two stars can either be close, with the planets out further and orbiting the double stars’ center of gravity, OR the stars can be so far apart that they each have their own little planetary system. Roll it! Odd for close, even for distant. And if you instantly say “No, hate that idea!” Then go with the other.
But what kind of star is it? Again, what does the plot need? If it needs “enough like our Sun that there’s a habitable planet” roll a dice. Odd it’s “a few percent larger than the Sun” even is “a few percent smaller.” That’s close enough. Unless you’re writing science, and then you need to put the dice away.

A planetary system. Roll the D20. That’s how many planets are in your system. But which planet is the one your intrepid explorers,/colonists,/crashed rich idiot/pirates are going to call home? I’d pick one somewhere in the middle. But if you rolled a twenty, you might want to roll a D6 to see which one you’re on.

See how much time you save, baiting your subconscious like this?

Is the gravity lighter or heavier than Earth’s? By how much? [D20—1 to 10 is lighter by that percent, 11-20 is heavier by that percent] What? You don’t like it? That your sub conscious saying nope, nope, nope! So roll again or make up your own rules. Just don’t dither around for an hour about it, Okay?

Is the air breathable? If it needs to be, for the story, then you declare that it is indeed breathable. No need to roll.
If it needs to be not breathable, can it be processed and used? Can it be changed so it is breathable? Same again. What does the story need?

Now let’s talk moons. Roll a D4. No, nothing bigger. You’ll thank me when you try to develop a calendar based on the various moons.

Right, now you’ve got this big blank sphere. Okay, don’t be pedantic. Oblate spheroid. So here’s your world.

Twenty areas. (You can split it up as much or as little as you want!) get out the D10 and start rolling. That is the amount of dry land in each section. You don’t have percent dice? You can fake it, I trust you.

Wait! Where’s the open ocean! Oo didn’t come up very often.

Okay, remember your story? That plot? Is there anything the requires lots of land vs lots of ocean? Do you want a desert planet or a world full of island archipelagos. Or large Islands like the British Isles, New Zealand, the Philipines, Japan . . . you can reverse the percentages, or swap a couple of sections. If you can’t make up your mind, get out the twenty-sided and reduce the areas by that much.

Now, look for some patterns. The purpose of this exercise might be to mimic random nature, but the human eye sees patterns. High percent sections that might link up into big continents, or block a circum-equatorial current. Grab a pencil and scribble in roughly that percentage, don’t bother with making it neat, you may be doing some erasing, as you decide to connect it to the next block, or wait! A dangerous narrow strait right there . . . the equatorial current roaring through . . .

You can roll for other things as well. Percent mountainous, swampy, desert, forested, pseudo grasslands . . . I probably wouldn’t bother getting this detailed this early in the process. But if you want it detailed, you can do it.

How are the poles looking? Want some ice caps? Can’t decide? Roll a die. Odd yes, Even no.

Native vegetation? If the air is breathable, you’ll at least have algae in the oceans. Does your plot have anything to say about this, or are you just going to go with the flow and deal with whatever’s there, just like your characters are going to have to do.

Uh, do you excessively identify with your characters? This is where you really do need to step back and be the god of the story.

Oh . . . Kay. More dice rolling.

1 = nothing but prokaryote algae
2 = ocean life—edible (mostly)
3 = ocean life—inedible (mostly)
4 = land plants—edible (mostly)
5 = land plants—inedible (mostly)
6 = small primitive land animals (pseudo-bugs and such)
7 = huge dangerous land animals (dinosaur sized)
8 = dangerous poisonous animals (pseudo snakes, poison arrow frogs etc)
9 = large dangerous land animals (pseudo elephants, predators to match)
10 = Reasonably sized yummy critters
11 = Intelligent life, primitive
12 = Intelligent life, civilization
13 = Intelligent life, industrial age
14 = Intelligent life . . .

Well you get the idea. When you get far enough down the list that you start squirming and going “Nope, nope, nope!” stop the list there. Or add anything you think of, and roll the appropriate die. Don’t like the results? Roll it again until you get the one you actually want, whether you consciously realized it or not.

Look, you’re communicating with your subconscious. This works better than an Ouija board. Maybe.

Now. Pick a place where the story is going to start. Land (or crash) your ship. Have the malfunctioning transmat dump you. Right. There. Whatever.

Firm up the land’s details as they crawl out of the wreckage and start looking around.

Have fun!

And read a good book. Or my new one:


  1. Of course, if one is punch drunk from short sleep, and one wants to do some sort of complicated megastructure, one has to adjust the process a little.

    There are some free student editions of ANSYS. My intuition is that one could do multi-sun stresses and strains by using a custom function in one of the solids solvers.

    1. But will you regret it in book three when you have to figure out what season it is and which sun is where, and how long the night is, when your Characters need to do some sneaking around?

  2. Heh.
    I thought I was working at an abstract level by considering what reversed rotation would do to prevailing winds and rainshadows.

    Or differences in fantasy race longevity giving rise to the heir of a usurped king being in the prime of his life while the succeeding dynasty just crowned the third king. (OK, it was an excuse to smash Stephen I and Bonnie Prince Charlie into one another. But the excuse came first.)
    ((BTW, if you want to play with that one, feel free. I kept piling on what-ifs and themes, and it became kudzu. Great for a gameworld where PCs determine their focus and stuff happening in the background just adds flavor–especially when the PCs face difficult trade-offs. Not so great for telling a coherent story.))

    1. Playing with the Coriolis effect?

      Mind you, having the Atlantic hurricanes going from west to East and hitting Africa and Europe regularly is an interesting idea. And a hurricane, if it hit the warm Mediterranean water would really mess up a lot of places.

      Of course, the continents would most likely be in different places and so forth, but it is interesting to think about.

      1. Dang it, now I’m wondering what sort of cultural developmental changes would happen with a humid southern Europe and a drier northern Europe that lacked the Gulf Stream’s temperature and moisture buffer…

        1. Making water wheels unreliable in the north, and more practical in the south. And northern Africa wetter? “Great storms” when a hurricane did make it past Gibraltar?

      2. Hurricanes are already not all that tidy, especially if you look beyond the puny ones that come ashore in the U.S. and stop thinking of ’em only as those perfectly round donuts, but rather consider them as a stable, concentrated low pressure system that generates a circling pattern of high wind (upward of 60mph but 140mph isn’t uncommon). By that standard there’s a more or less permanent mega-hurricane just off Greenland, and another that frequents the Bering Strait; last spring one wandered across Hudson Bay. The “Storm of the Century” that buried Wyoming back in 1949 was in fact a land-based winter hurricane, about five times the size of those that hit Florida. (Pretty obvious once you look at the wind and pressure maps; classical hurricane structure. Siberia has these every winter.) Quite common for Antarctica to have several (usually five at a time) massive hurricanes in orbit, which is why in the era of sailing ships, rounding Cape Horn was nearly a suicide mission.

        Of course since hardly anyone lives in these places, and this is just their normal everyday weather, it’s not News. So if you have natives in such areas… or greenhorns… very different attitude and behavior. Make your world big with a lot of axial tilt or an eccentric orbit and watch the weather go nuts.

    2. There have been many changes even within the last few thousands years, like IIRC lions in Europe, and the Sahara was smaller.

      1. Coming out of the Ice Age, all the climate zones shifted. So some extinctions were environmental, and others were hunted by the growing human population.

  3. Oooh! A new book! And I didn’t catch 13 when it came out, so TWO new books! Is it too early for lunch so I can start reading? I suppose I could go out for breakfast…

    BTW: I had to try really hard to buy them. Amazon was quite insistent that I get them via Kindle Unlimited. (I re-read your stuff, so I want it persistent. Probably time for a backup.)

  4. *sweeps her tectonic maps under the rug for the moment and whistles innocently* (Now I just have to figure out why the bay in one of my countries is so VERY nasty… as in ‘takes magic to reliably get through and is nicknamed the Heartache of the Sea.’)

    1. As a geologist, I usually wind up inventing spreading ridges (especially fun on land) subduction zones, and mark the currents . . . I do eventually get around to writing the story.

    2. How about a volcanic hot spot? you can have an active volcano under the water, gas bubbles coming up through the water, mysterious and dangerous islands, strange and sudden water currents, and wars between fire elementals and water elementals. You could make the whole bay a caldera for extra fun.

  5. This exercise reminds me a LOT of Orson Scott Card’s “Thousand Ideas in an Hour” convention sessions, which he discusses in his book on how to write SF/F. He does (or at least did – dunno if he’s still doing conventions) these to demonstrate how easy it is to come up with a detailed idea to build a story around.

    I’ve tried it a few times myself, but found that I rarely get as far as a coherent plot. Me being a zoology/ecology/evolution nut, I tend to get absorbed in designing the biosphere. Big animals, little animals, carnivores, herbivores, parasites, scavengers, marine animals, land animals, aerial animals, plants, microbes, food webs, predatory methods that never evolved on Earth…

    1. Eat your hearts out, folks…
      Because I don’t have a problem inventing new worlds, or modifying well known ones. I try to stay more-or-less away from fantasy, which imaginary worlds tend to be. Instead, I populate Mars not only with humans (who settled the place first, thousands of them; read MARS and the predecessor, BEMs), but with the Flickers, who start out simple and over the course of MARS, my new novel Pirates, and the WIP Hybrids, become exceedingly complex; and the Felis, catlike aliens who are far more intelligent than the Flickers (who created them) ever realized!
      Run-on sentences? Who, me? :O

    1. Software to do much of this exists. The venerable “accrete” program will do the basics of star system generation, including planetary details like planetary type, radius, density, gravity, temperature, percent water, atmosphere, etc. There are some semi-realistic planet-scale map generators, too. The Platec 2D plate tectonics simulator started as somebody’s university project. There’s the web-based Experilous Planet Generator (http://experilous.com/1/project/planet-generator/2015-04-07/version-2) – less realistic but kinda cool. There’s a host of other software out there, too.

      1. a lump of source code written in 1988 for a command line program isn’t helpful for the vast number of people.

        1. Oh, there’s a zillion ports of “accrete” floating around out there, including a web-based one and I think some binaries, but I can’t remember off-hand where I found them just right now. I ported one of them to C#, but never finished porting the atmospheric composition part, IIRC.

          1. yeah i guess there just isn’t enough people doing sf worldbuilding to warrant making an integrated solar system builder

        2. Hmm… I might have to put some time together to look that up. Depending on what it’s written in, it might not be too hard….

          Oh who am I kidding, I’ll never have the time. But it does sound interesting.

          1. I found a few moments to search and found the one I was thinking of: StarGen. Not actually web based, but does feature HTML as output. Example star systems, binaries for various platforms, and source code are at https://eldacur.com/~brons/NerdCorner/StarGen/StarGen.html

            Of course, this is all based upon models of star system formation that date back decades. There may have been some advances in astronomy and astrophysics since that invalidate it, but it certainly isn’t my field of expertise.

  6. I tend to start my world-building in — odder corners.

    Then, of course, I can decide that I’ve got a flat world if I so desire. 0:)

    1. My stories tend to start in a small place, and build out. The major world building tends to happen after I’ve got people in place and dong things. As I yell at my subconscious “Stop! Stop! I need to figure out where everything is!”

  7. I have one like that, tho thank all the gods no one needs to sail on it. Lessee… here’s the description as seen from space:
    A vast brown continent sprawled from equator to southern pole, flanked by a spatter of steaming volcanic islands. A swath of green slouched up from the ocean, across the shallow bowl of the western plain and up to the rocky feet of the encircling mountains. Two large moons pulled the ocean to and fro, cutting deep tidal bays along the coast; half a dozen gigantic hurricanes cruised the northern ocean, where a massive polar ice cap gave the planet a peculiarly lopsided appearance. Ecoformed it was, but the job had never been finished.

    Basically a lot of water being dragged around by moons with contrary orbits, with only the southern currents being deflected by land, considerable axial tilt, and barrier mountains backing a huge crescent bay, which probably started life as an asteroid strike… nope, you don’t want to go sailing out there, no way. Main effect for our guys on the ground is seasonal extremes with high winds. We don’t really care; we’re using the place as a refugee camp and for economic warfare (at least, once we get the spaceport built).

    1. Oh sure. You can roll up just about anything. Saves a lot of time agonizing over things that (1) Are just as well done randomly or (2) Your instant rejection clues you into what you do want.

  8. I remember using maps from the Civilization computer game (I’d have the computer play itself to speed things up) for an old Traveller game I ran for a little while.

    Not only gave me the continents and islands, but resources and city placement.

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