Flat World design

Gilladian

Adventurer
Just as an exercise, because I've thought about it off and on for years, and have never quite wrapped my head around it, I would love some input on designing a "flat world" campaign setting.

Here are my ideas so far:
1) the world has an ocean in the center, a ring of mountains on the exterior, and rivers that run down from the mountains to the ocean.
2) There is no sun, and no moon(s). Day is simply "when the sky gets light" and Night is the opposite. There are times of "nightglow" but there is no actual moon (unless we invent a way to have one).
3) burrowing through (or climbing over) the mountains in the outer ring would only end up "coming out the other side"; the dwarves probably make a lot of money creating travel short-cuts this way.

Questions: Seasons? What's "up there?" and "down below"? What does the source of a river look like? Are there other planes? Is there an underdark? Is there a "backside" to the world disc? Is there really even a "disc" if there's a wraparound effect?

What would your answers be? What other questions need to be answered?
 

aco175

Adventurer
If there is no sun, then there would not be any evaporation of the ocean to make clouds and the rivers that come down from the mountains.. No rain makes a lot of arid places and no trees. There should be something that makes the evaporation and clouds come out from the middle of the world to the mountain ring.

There should also be some spinning of the world to give the world some mechanism for the clouds to travel to the mountains. This could also explain some seasonality.
 

Umbran

Mod Squad
Staff member
If there is no sun, then there would not be any evaporation of the ocean to make clouds and the rivers that come down from the mountains..
That's not quite correct. On our world, sunlight and air heat water, and that heat is what causes the water to evaporate. Any heat will do - it doesn't have to be direct sunlight. Direct sunlight means th water is heated more than if there were, say, clouds, but doesn't stop the process outright.

That being said, this setup is weird enough that appeals to our own planet's dynamics will fail - like how that disk is not gravitationally stable, and would normally collapse into a round world. The fact that tit doesn't means there's something else going on, which is perfectly acceptable for a fantasy world. It is just.. the wter cycle is probably the least of the world's problems in that regard.


There should also be some spinning of the world to give the world some mechanism for the clouds to travel to the mountains. This could also explain some seasonality.
Or, you just have a solid domed sky - water evaporates, reaches the lid, and it rolls down the sky to the edge of the world - like on the inside of a pot lid - where it flows into the rivers coming from the mountains. Sometimes it'll just drip off the lid, too, and it'll rain.
 

Gilladian

Adventurer
Oooh! I like the lid idea. That could also explain stars - the stars are tiny flaws in the crystal dome over the world; maybe there could even be mythology about "things from outside" attacking the world's dome/lid. I imagine a fairly shallow curve, like a lens, sitting on the top edge of the mountains. There could even be some sort of ridges directing the water to run down to specific places where the rivers are.

As far as the sun providing heat and evaporation, I could see maybe having a "hot spot" at the center of the sky. And it could slide around a bit to provide uneven warming to create currents.

I'm not at all worried about the answer being "magic" or "the gods" - it is a fantasy world after all! But I would like to have SOME form answers for big questions.

I don't see this world as being enormously large - maybe only a thousand miles across, or a couple thousand at most. That's big enough to have some good areas of diverse geography, like a desert and a large swamp, but small enough to be manageable in other ways.

I wonder if the "sun spot" could also vary in overall heat intensity over the course of a "year" - warmer in summer, cooler in winter obviously - that would help create seasons, right?

Or seasons could simply be a religious matter - perhaps each "season" is a particular god's purview, and they rotate power over the course of a year, allowing each season to occur as a signal that the particular god is dominant at that time.

This is fun!
 

TwoSix

The hero you deserve
I run Ravnica as a flat world, about 160 miles in diameter. The world is bounded by unbreakable walls. There's a "sun" that moves across the dome every 10 hours, followed by 10 hours of night (although the amount of magical light generated by the city means it's never really "dark").

There's water in caverns underneath most of the city, about a mile or two miles deep. At the bottom is more of the same unbreakable material as the walls.

Part of the campaign mystery is finding out what's underneath the "bottom". If/when they get there, they'll find a pristine, untouched realm divided into mountains, plains, islands, swamp, and forest. It's basically a reservoir of mana, which is recycled by the "sun" (which actually just collects ambient mana) every daily cycle.
 

aco175

Adventurer
Maybe some sort of mysterious island in the middle of the ocean where life originated or at least the original or favored race according to myth. This may be elves or dragons for all that matters. It may make some good dynamics.
 

Gilladian

Adventurer
I think 1000 miles as a radius. That's ample, especially if there is also a full underdark layer or layers. And I have always liked the idea of the feywild/shadowfell as the ONLY alternate planes - a chaotic, natural world filled with elemental and fey creatures, and a shadow world filled with ethereal and undead creatures. None of the 4e mythology, though.

What other major "world level" questions need answers?
 

MarkB

Hero
How do lycanthropes work if there's no moon? Is there a regular pattern of lighter and darker nights?

What do people say as directions in this world? Is there one particularly prominent (and maybe iron-rich and thus magnetic) mountain that people consider 'north'? Are there constellations or other visible features to provide guidance at night?
 

Dannyalcatraz

Moderator
Staff member
I think 1000 miles as a radius. That's ample, especially if there is also a full underdark layer or layers. And I have always liked the idea of the feywild/shadowfell as the ONLY alternate planes - a chaotic, natural world filled with elemental and fey creatures, and a shadow world filled with ethereal and undead creatures. None of the 4e mythology, though.

What other major "world level" questions need answers?
Are you going to run Tabaxi or Rakshasha as the main antagonists? You know...because they want to push everything over the edge?
 

Gilladian

Adventurer
Are you going to run Tabaxi or Rakshasha as the main antagonists? You know...because they want to push everything over the edge?
That's really good... what sort of villains would Tabaxi make, even? They seem more victim than aggressor. And any individual Rakshasa is a fine villain, but they're too solitary, too arrogant, to be team players and form any sort of villainous power.

I suspect Dragons would be the arch-villains. 4 dragon "gods" rule over the 4 seasons, and say 12 apex predator dragons rule the world. 8 on the land, one in the central sea, and 3 underground, in the underdark realm.

But what sort of backstory would there be? How would adventure happen? What's the way to give characters a space to inhabit?
 

Dannyalcatraz

Moderator
Staff member
That's really good... what sort of villains would Tabaxi make, even? They seem more victim than aggressor. And any individual Rakshasa is a fine villain, but they're too solitary, too arrogant, to be team players and form any sort of villainous power.
Perhaps a Rakshasha- or small group of them- pulling the strings* of Tabaxi enclaves, eventually honing them into a dangerous threat? Perhaps telling lies about their racial past, telling tales of a lost empire erased from history.

Infernal catnip unleashing a flood of heretofore only rumored Tabaxi berserkers?





* so to speak
 
Just as an exercise, because I've thought about it off and on for years, ...
Questions: Seasons? What's "up there?" and "down below"? What does the source of a river look like? Are there other planes? Is there an underdark? Is there a "backside" to the world disc? Is there really even a "disc" if there's a wraparound effect?
What would your answers be? What other questions need to be answered?
So, way back when, I guess c1985, I did decide on a flat world.

It was contained in a rotating iron sphere, so the 'fixed stars' were actually on the sphere, as were the planets, which moved independently - and literally wandered, not following orbits. What they were - crystals, flames, holes, angels, cities, spiders - was something that was never confirmed.

The sun was a deity (though which deity seemed to depend on who was looking), crossing the sky every day, with schedule & route determining the season. One consequence of that is there is no difference in the length of the day or the season, however far north or south you travel. But quite a difference in the declination of the sun and the warmth received. The moon, OTOH, was a habitable terrestrial land in its own right (which the PCs actually visited at one point).

The in habited land masses were towards the center of the world-disc, surrounded by ocean - presumed, in theory, to be held in by a ring of hills along the world's perimeter, also never confirmed.

The world was thicker than the greatest mountain was tall - plenty of room for an Underdark, though there wasn't anything quite that extensive - but, legend had it that dwarves once did, in fact, dig a mine so deep they fell from the bottom of the world.
 

Sadras

Adventurer
Perhaps Yuan-ti run this world with a Marilith at the apex - so essentially this just one or part of one of the 666 levels of the Abyss.
 

Panda-s1

Scruffy and Determined
uh, is no one gonna bring up discworld? I was pretty sure that figured out how a flat world can emulate our round one (albeit with some comedic flourish I'm sure).
 

Tonguez

Adventurer
Giving the ocean a supervolcano at its center would explain how the ocean is heated to steam which rises to the crystal dome where the water evaporates to form rain. Make it like a regular geyser that blast water into the sky, thus accounting for both clouds and tides. This way you dont need the hot spot in the sky (you’ve got a hot spot in the ocean instead)

Seasons could be due to rotation of the hot water from the source flowing in a constant current around the disc. The head of the flow is hottest (summer) but dissapates as it goes around leaving a cold tail (winter). Winds blowing inland and flow into bays etc cause regional weather effects but there would be a constant swell pattern and rim-wide trade wind too which would make navigation easy with the current, but difficult against it.


Addendum: Have the Geyser blast cause the Crystal dome to glow brightly and then dim, causing the same day and night cycle to occur simultaneously across the disc:)

uh, is no one gonna bring up discworld? I was pretty sure that figured out how a flat world can emulate our round one (albeit with some comedic flourish I'm sure).
Pratchett essentially handwaved it as narrativium, however

“Since the disc's tiny orbiting sunlet maintains a fixed orbit while the majestic disc turns slowly beneath it, it will be readily deduced that a disc year consists of not four but eight seasons. The summers are those times when the sun rises or sets at the nearest point on the Rim, the winters those occasions when it rises or sets at a point around ninety degrees along the circumference."
—The Colour of Magic, footnotes, page 5
 
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Blue

Ravenous Bugblatter Beast of Traal
2) There is no sun, and no moon(s). Day is simply "when the sky gets light" and Night is the opposite. There are times of "nightglow" but there is no actual moon (unless we invent a way to have one).
Have you thought of the ancient Greeks, where the sun was thought to be a chariot that was driven across the sky every day? In a non-Heliocentric approach the sun and the moon do not need to be large nor at astronomical distances.

3) burrowing through (or climbing over) the mountains in the outer ring would only end up "coming out the other side"; the dwarves probably make a lot of money creating travel short-cuts this way.
There's a shape that does that, a torus. But it's not flat.

Questions: Seasons? What's "up there?" and "down below"? What does the source of a river look like? Are there other planes? Is there an underdark? Is there a "backside" to the world disc? Is there really even a "disc" if there's a wraparound effect?
Just more questions. What causes the daylight and nightglow? Why do plants bloom? Can you dig deep enough and fall off the bottom?
 

Umbran

Mod Squad
Staff member
uh, is no one gonna bring up discworld? I was pretty sure that figured out how a flat world can emulate our round one (albeit with some comedic flourish I'm sure).
I don't think it "figured out" a flat world, in the way we are talking. For instance, at the rim of Discworld, the water just cascades off in a great waterfall. Pratchett does not discuss how the Discworld gets new water - it is limited to the statement that, "arrangements are made".

There is no problem with just hand waving that. Water comes from somewhere. It rains... because rain is a thing that happens. Don't worry too much about it.
 

Panda-s1

Scruffy and Determined
I don't think it "figured out" a flat world, in the way we are talking. For instance, at the rim of Discworld, the water just cascades off in a great waterfall. Pratchett does not discuss how the Discworld gets new water - it is limited to the statement that, "arrangements are made".

There is no problem with just hand waving that. Water comes from somewhere. It rains... because rain is a thing that happens. Don't worry too much about it.
I mean okay, but I know he figured out the sun and the moon by having light move at an incredibly slow speed. or something like that. the point is he figured some stuff out, even if it was hand wavey.
 

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