How can I fix the problem of scale in a Sword and Planet fantasy setting?

[Jervis]

Hello all! I'm making a sword and planet style fantasy setting and I'm aiming for a treasure planet style feel of ships sailing between planets. The issue here is scale where realistically a ship couldn't move through a solar system in less than a year or 10 without moving at a speed where it can crush a planet. Just watch last jedi to see how FTL of that sort can break a universe and solve every problem with a Kamikaze.

The void between worlds is filled with a lighter than air gas that ships can sail through by catching a current. So all you really need to do is get a boat past the planet's atmosphere to start sailing. I've considered using that as a sort of space compression effect to make distances between planets shorter from the perspective of people in a ship. That has it's own problems though and i would like to find something more elegant. Anyone willing to share ideas?

[Bohandas]

Well Spelljammer made timely travel between starsystems reliant on fast moving currents in the phlogiston without which the ships were far far slower, and they had to slow down to magically pass an otherwise impenetrable barrier to enter the star system

[Mechalich]

Useful cheat: in our reality the speed of light is as fast as you can go, but in a fantasy world there is absolutely no need for that to be true. In fact, this is particularly useful because this change only really impacts stuff effects where relativity comes into play, which is essentially nothing at all at ordinary human scales.

In terms of the kamikaze issue - space is big, everything in space other than stars is effectively tiny. A sailing vessel cannot control its heading with any sort of precision (such a ship is lucky to hold to a single degree of accuracy, which wouldn't be enough for a ship departing from Earth to even manage to slam into the Sun). Therefore you can prevent kamikaze strikes by making such that anyone who tries to ram something at absurdly high speeds (if you suspend relativity this is a simply Newtonian mechanic as well, which actually means you can go faster while hitting things less hard) simply by having them miss and streak off into the void when they try. As long as acceleration to extremely high travel speeds takes a significant distance this is pretty effective.

[olskool]

Hello all! I'm making a sword and planet style fantasy setting and I'm aiming for a treasure planet style feel of ships sailing between planets. The issue here is scale where realistically a ship couldn't move through a solar system in less than a year or 10 without moving at a speed where it can crush a planet. Just watch last jedi to see how FTL of that sort can break a universe and solve every problem with a Kamikaze.

The void between worlds is filled with a lighter than air gas that ships can sail through by catching a current. So all you really need to do is get a boat past the planet's atmosphere to start sailing. I've considered using that as a sort of space compression effect to make distances between planets shorter from the perspective of people in a ship. That has it's own problems though and i would like to find something more elegant. Anyone willing to share ideas?

As has already been suggested, you can use a multi-faceted system for Orbital, Interplanetary, and Interstellar travel. This is how I would set it up...

Each planet has a "Zone of Influence" where it can affect other bodies. This "Zone of Influence" is as far out from the planet as 10 TIMES its size in distance. Traveling from orbit in this zone allows you to travel at roughly 1,000km per hour per "knot" of speed. So a ship "sailing" at 6 knots would cover 6,000km per hour.

Once you leave a PLANET'S Zone Of Influence, you can magically sail on the Aether between worlds at 100,000km per hour for every knot of speed the ship does. You could also use the measurement of ASTRONOMICAL UNITS, which is just shy of 150,000,000km. That way you could use the realistic distances between planets (at least in our own solar system) as a measure of distance, and by extension, time.

Finally, as you leave the influence of a system (say about 100 times the Star's diameter) to hit Interstellar Space, the Aether would allow you to travel 1 Light Year per day per knot of speed.

You could then add navigational hazards like "slip-streams" that speed up or slow down the rate of travel just like a current would. Other hazards might include either fixed or randomly moving "doldrums" where the relative speed of the Aether slows down (even up to real speed) for significant distances. Pulsars producing "waves" of Aether that can damage a ship by "pushing it" in another direction at random intervals. and inescapable gravity wells (black holes) pulling a ship towards them or slowing the aether down significantly.

You could also have ship captains perform stunt-like ship maneuvers where they enter inner zones in such a way as to preserve the speed they had in an outer zone, thus "sling-shotting" themselves into orbit very quickly to avoid danger or to beat a rival to port.

The following thoughts assume you envision space travel as craft SAILING on a "magical sea" of Aether. The ships would deploy "sails" that catch this Aether and otherwise act exactly like ships sailing in water with the exception that they can sail in THREE DIMENSIONS. First, I would actually vary the "strength" of the Aether the same way that winds vary on Earth. You may have flows ranging from 1 to upwards of 100 knots of "wind." The ship captains could then make skill checks to exploit these "Aether Winds" to increase their vessel's speeds in a given Zone.

You can also get fancy with SPACIAL RELATIONSHIPS. The ships could have their location marked on an X-axis, Y-axis, AND in a Z-axis (vertical distance above or below the center of the solar system). The Z-Axis would be called out as: "[insert distance in Km here] either above or below the Ecliptic." The Ecliptic is ZERO kilometers from the vertical center of a solar system. So a captain would say: "We are 300km below the Ecliptic" if you were sailing UNDER the Earth as you passed her.

By imagining space like an ocean made up of "energy" with currents, hazards, and varying "depths" (read as speed ratios), you will give your ships a "world" worth "sailing" in!

[Jervis]

-snip-

Wow, thanks for that. That’s a really insightful list of ideas.

[brian 333]

Speed is dependant on the interplanetary winds, so have the speed of the winds inversely proportional to gravitational density. Near a star the winds are away from the gravity's pull, so sailing into a headwind stronger than the ship can counter means you can never sail into a star. One might quarter into a gas giant's winds and orbit downwards slowly. Planets are easier to crash into, and asteroids even easier, but the repulsion effect of wind direction pushes sailing bodies away from masses, slowing them down as the ship nears the mass. Crashing full speed into an asteroid results in a shipwreck similar to a naval ship crashing into a reef.

As one gets more distant from gravitational bodies, wind speeds increase. Gyres and currents move much faster than light in the interstellar void, and anyway, stars are much closer than in our universe. Charts and maps are valuable; if one does not know the currents it may take weeks or months to get where you want to go. Charts reduce that time, but some places will always be hard to get to because the prevailing winds blow contrary to the sailing ship's intended course.

[Eldan]

I mean, my first question is, "why does it matter"? You can make your setting as unrealistic as you want. Your ships are already sailing in the aether. Why keep the planets a real-world equivalent distance apart?
We've all seen illustrations like this:


Just have them close together.

As an example, I'm currently playing Sunless Skies. It's a game about travelling through space on a flying steam train. It's never explained about how they work, they just do. Travel between stars uses crystallized time as a fuel, which is mined from large frozen mountains.

[Jervis]

I mean, my first question is, "why does it matter"? You can make your setting as unrealistic as you want. Your ships are already sailing in the aether. Why keep the planets a real-world equivalent distance apart?
We've all seen illustrations like this:


Just have them close together.

As an example, I'm currently playing Sunless Skies. It's a game about travelling through space on a flying steam train. It's never explained about how they work, they just do. Travel between stars uses crystallized time as a fuel, which is mined from large frozen mountains.

Fair enough. The setting is mostly inspired by a weird mix of Sinbad, Treasure Planet, old pulp sci-fi, and a bit of anime nonsense. The whole thing is a mess of technology that makes no sense together anyway like broadswords and laser cannons and a magic system inspired by myths of stealing fire from the gods anyway so might as well lean into it

[Yanagi]

Hello all! I'm making a sword and planet style fantasy setting and I'm aiming for a treasure planet style feel of ships sailing between planets. The issue here is scale where realistically a ship couldn't move through a solar system in less than a year or 10 without moving at a speed where it can crush a planet. Just watch last jedi to see how FTL of that sort can break a universe and solve every problem with a Kamikaze.

The void between worlds is filled with a lighter than air gas that ships can sail through by catching a current. So all you really need to do is get a boat past the planet's atmosphere to start sailing. I've considered using that as a sort of space compression effect to make distances between planets shorter from the perspective of people in a ship. That has it's own problems though and i would like to find something more elegant. Anyone willing to share ideas?

I bashed my head against a solar system fantasy for a bit before realizing that there's really no way to reconcile actual scale--in which we are insignificant in a way that triggers existential horror--nor how the indifference of physics to human scale effortlessly kills--with the prime conceit of adventure stories that the events are driven by the agency of individuals. Someone mentioned Sunless Skies, above, and it and it's predecessor Sunlesss Sea are great games but they're exercises in dis-empowerment of the individual--you die over and over, only beginning to accumulate information and resources over generations, always with the possibility of losing everything by reaching too far. But compared to this solar system those play environments are so much smaller and so much less instantaneously lethal.

My advice is: go nuts and don't even acknowledge how things "realistically" should be, because realism is antagonistic to any kind of fair system of gameplay and most kinds of "the party ventures forth" stories.

So I've got a world that started out as a conventional planet (with tectonics and geological history and such) but as I've realized that the science didn't add anything to the play or the lore, I've been making the setting more and more fantastical, with multiple explanations--myths, just-so stories, philosophical models based on first principles rather than measurements. There's a lot of moving parts to that...for example, there's a massive mountain range that looks like the product of a tectonic collisions but in all seriousness may have been made by the restless sleep of a cosmic snake that eventually swam north bearing a subcontinent on its back...but here's how the solar system works.

The sun is less a ball of burning gas and more like the alchemical image of the Central Fire; it takes the colorless non-matter that is the static and quality-less resting state of existence and turns into into substances with differentiated qualities: light, matter, motion, and spirit are all products of this combustion. Everything hangs near the sun is believed to be emesis from it...equivalent to the byproducts of combustion that cover the ground and fill the air around a fire. Stand on the surface the setting world and in the night sky there would be the far stars--the winking white light of central fires far away--by also the more variable and dynamic near stars...bright objects within the cloud of existence that can be tracked but don't necessarily remain fixed relative to an annual cycle--but also the disasters that appear with no rhythm or reason. Some times there are color fields, glowing gaseous formations, and other things.

There's no space travel, but the kind of philosophers that study the sky speculate about travel in the zone of phlogiston (space within the light of the central fire) versus the undifferentiated ether (space either outside of or unaffected by the central fire) because there's a robust mythology that speaks of creatures from beyond or before the light making a place for themselves within it, as well as contemporary tales of creatures that travel between central fires. The standing theory is that since undifferentiated ether has no qualities, beyond the reach of the central fire distance might not exist, and that even within the smoke-and-ash cloud of phlogiston absolute distance might be...slippery...between celestial bodies, and the differentiation of ether produces all kinds of exotic states of existence (contrasted with the mostly-stable substances that form the material and spiritual worlds, which while not perfectly catalogued tend to be consistent in whether they take up space).

I'd propose the solution to your system is something similar: there's no vaccuum, but rather a cosmos of varying viscosity.

In the inky black near and far are elusive concepts, and with the right tools (magic technobabble, in skill or item format) one can slip from place to place quickly...hours, days...though perhaps there is some equivalent to "weather" or "gyres" that could impede transit. In the black there's not really speed in any conventional sense of...intentional thrust in a direction...travel is being pulled from one point to another point. You fall of the edge of one sun's reach, endure the sense-crushing blackness, and and wash up on the outskirts of another sun's reach. Within the solar field there are faster and slower regions of transit...different ethers, different currents...and thus there is the perception of time and passage through "regions" of space with identifiable qualities. Since celestial bodies moves--maybe that means regular orbital dynamics, maybe that's something more chaotic or thematic that doesn't reflect physics--it takes knowledge and savvy to actually do the sailing between locations.

And within the stellar field worlds are the most stable things, the most consistent in how far fixed point 1 is from fixed point 2, and landing on a planet after travel in the ether is more like depressurization than de-acceleration. Try to cross into a world fast and you get smashed against the membrane between the loose reality of the ether and the concreteness of material existence.

ETA:

Oh, I guess the Gordian Knot answer to this is: simply prime players to understand that it's part of the setting to just say, "your travel time is one year, roll to see if there's an encounter, now we skip to you landing on the next world." Approaching the problem of scale from the other side--making a world where people are long-lived such that a 10-year journey is normal, unremarkable--would actually convey a sense of wonder about scale.

What this runs afoul of is...yeah, with this set-up whoever can control a spacecraft can weaponize the technology that allows high speeds. But technically, any setting where mass and acceleration work like the do in real life means that anything with mass can, via thrust, be used for kinetic bombardment. Einsteinian behavior at relativistic speeds might kill a planet more elegantly by smearing it into plasma, a sufficient amount of Newtonian mechanics--take big thing and throw it-- would under most circumstances obliterate a planet's surface.

[Mechalich]

One way to make a star system legitimately more compact is to host it around a red dwarf star. The TRAPPIST-1 star system has 7 planets, all of which are significantly inside the orbit of Mercury. The only issue with a setup like this is that astronomy tells us such planets would be tidally locked to their star which is...a problem in terms of conventional Gaian worlds. But you can finesse that easily enough.

[Bohandas]

One way to make a star system legitimately more compact is to host it around a red dwarf star. The TRAPPIST-1 star system has 7 planets, all of which are significantly inside the orbit of Mercury. The only issue with a setup like this is that astronomy tells us such planets would be tidally locked to their star which is...a problem in terms of conventional Gaian worlds. But you can finesse that easily enough.

Would it be possible for them to routinely eclipse each other

EDIT:
Of if we want to get more fantastical the sun could blink

[brian 333]

As we sailed the planet's seas our canvas sails caught the world's winds which drove us by their whims and our good Captain's cunning to our destinations. But then, when the tides of the skies were just right, we furled the canvas sails and unfurled sails of gossamer and midnight, and caught the winds of the stars. By their magic and our good Captain's will we rose up from the surface of the ocean and sailed into the night sky.

[Mechalich]

Would it be possible for them to routinely eclipse each other

It is actually believed that this regularly does happen. Also the planets would be quite large in each other's skies, at a significant fraction of the size of our moon, with discernable disks (they also might also have remarkably consistent pathing, due to orbital resonance).

Of if we want to get more fantastical the sun could blink

Red dwarf stars tend to be considerably more unstable compared to stars like our sun, regularly throwing off rather massive flares. While planets with strong magnetic fields (like Earth) would be generally protected, those without them would be periodically blasted by furious baths of radiation. To those sailing within the star system this would be a massive hazard.

[Telok]

If you're using a aether/philostogon instead of vacuum you can simply have the speed of an object be limited by the amount of aether present. There's more/less aether closer to massive bodies to stuff has to go slower near them, its basically the same as the speed of light but lower & limited to mass instead of energy. Figure out the interactions you want and set the limits.

This lets ships go really fast when away from planets & asteroids, but have to slow down when they get close. Use a modified square of distance law (don't write it down exactly, just name it and set the results at what you want) and it can have the old Spelljammer effect where two fast moving ships that would normally ram at 0.5c simply suddenly slow down a whole heck of a lot when they get close. Its like your ship is moving at "warp", then there's a 30 second slow down and suddenly you're back at near-planet speed with another ship 120 yards off the port bow heading at you.

[Yakk]

A few thoughts that might be of use.

Traditional sailing occurs at the surface between two fluids -- the atmosphere and the water on Earth. The body of the ship in the water (and its keel) plus the sail let the ship travel in multiple directions by trading off forces from one to the other. I think that is worth preserving in a space-sailing fiction.

If you keep this, you have the idea of currents, winds and tacking. Which should make people who like sailing on Earth happy.

Second, terrain or topology. The topology of a solar system is relatively boring, and it is energy based. You get things like hotzman transfer orbits and slingshots. Keeping some of these around might be fun, but I suspect you'll want more than that.

I mean, the science fiction bit about dense asteroid fields doesn't make sense in a solar-system like topology; in 3d space, an asteroid field has to be ridiculously huge to be a barrier to travel (and this is ridiculously huge on space scales), unless it is directly at the source or destination. Having an asteroid field "mid way" between places doesn't work.

3d maps are also hard to handle. So I'd recommend making your topology at least locally 2d through some excuse, making maps easier. (Even aviation on Earth is 2d, as the atmosphere isn't that thick, making it mostly 2d; travel distances is far greater than the height delta, so height is *tactical* not *strategic* or *logistical* in scale).

...

So mixing sci fi, age of sail and fantasy tropes...

Solar Wind should be a thing. This shouldn't flow strait out from a sun (just tend to). The Solar Wind should form storms, hurricanes, etc.

The Gyre should be the source of orbits. In a solar system, it forms something like a whirlpool, and planets flow on it. Around each planet produces a local whirlpool. The gyre basically replaces gravity for orbital mechanics.

I'd imagine the Gyre forming a flattened donut around each stellar body. This produces a two-surfaced membrane at the edge of the Gyre you can pilot ships on. Planets would form a sub-gyre on the gyre of the star, a sort of pinching-off of the solar Gyre, and the planetary Gyre merges into the solar Gyre at the edge.

The Gyre itself is inhospitable to life (at least planet based life); so your ships stick a sealed hull into it. Monsters do come out of the Gyre; they are akin to sea monsters.

The surface of the Gyre is irregular, and it has waves and currents.

The solar wind blows over the surface of the Gyre.

This makes a solar system have a top and a bottom side (to the Gyre); crossing from one to the other requires a planet or similar, and braving the rough whirlpool around each. Asteroid belts would also produce Gyre effect, pinching the solar Gyre together and forcing ships to go through it. Asteroids can be as common as you want, but the Gyre itself will have nasty topology through them.

We can make up a name for the substance of the Solar Wind and the Gyre. Aethyr is good for the wind. Make up a word or steal one for the Gyre (Philostrem?). Then you can talk about how Aethyr storms cause Philostrem to scatter above the Gyre (aka, rain).

Ok, once you have this, your ships velocity is relative to the Gyre they are riding on, and the Aethyr they are being pushed by. Approaching a planet is tricky, because the topology of the Gyre makes it harder (You have to detatch from the Gyre to land on a planet?), and the Aethyr wind tends to be lower in the planetary Gyres than further away.

You can also shrink solar systems; they are more than a bit too large. Think in terms of travel time. Velocity is relative; but you do want ships going to another planet and those returning to interact, right? If your distances are too large, then they will pass by each other at insane velocities.

For ships to meet each other going in the opposite direction between planets, there needs to be local bottlenecks at which they are traveling relatively slowly (in opposite directions), or not that much distance between planets. To steal from orbital mechanics, Holtzman gates might be the name for the bottle neck places that going to and from a planet you have to travel through. There can be multiple Hotzman gates, and they are places where the Gyre isn't moving fast in any direction, and the only safe way to cross from one planetary Gyre to another.

So the topology I'm imaginging is a big solar pancake "gyre" with an (overall) whirlpool flow. This solar gyre is pinched off at each planet, which has its own whirlpool flow. Between planets there are fast-moving geodesic flows. These flows meet at Holtzman gates, knots in the gyre, that allow you to transfer from one geodesic to another.

The geodesics change as the planets orbit. There are well known ones, and more dangerous and less stable ones, you can take; this means that travel looks like a (combinatorics) graph. And Holtzman gates provide bottlenecks along paths between planets.

This gives you asteroid sholes, a reason to risk going through asteroids, fast long distance travel (along geodestics), Holtzman gate "nodes" on your travel graph (where you run into other travelers), no ability to ram planets, space-going vessels that look like ships and harness the solar wind. Interstellar geodesics that go extremely fast can explain why you can go far distances; the galaxy itself can produce a gyre, on top of which stars puncture it, or even multiple gyres (and going between gyres is dangerous and difficult).

And it uses a mixture of science fiction, real space and fantasy words.

[Thane of Fife]

One solution would be to have your ships sailing between the many moons of one planet, instead of between multiple planets. That greatly cuts down on the distances.

[brian 333]

A few thoughts that might be of use.

Traditional sailing occurs at the surface between two fluids -- the atmosphere and the water on Earth. The body of the ship in the water (and its keel) plus the sail let the ship travel in multiple directions by trading off forces from one to the other. I think that is worth preserving in a space-sailing fiction.

If you keep this, you have the idea of currents, winds and tacking. Which should make people who like sailing on Earth happy.

Second, terrain or topology. The topology of a solar system is relatively boring, and it is energy based. You get things like hotzman transfer orbits and slingshots. Keeping some of these around might be fun, but I suspect you'll want more than that.

I mean, the science fiction bit about dense asteroid fields doesn't make sense in a solar-system like topology; in 3d space, an asteroid field has to be ridiculously huge to be a barrier to travel (and this is ridiculously huge on space scales), unless it is directly at the source or destination. Having an asteroid field "mid way" between places doesn't work.

3d maps are also hard to handle. So I'd recommend making your topology at least locally 2d through some excuse, making maps easier. (Even aviation on Earth is 2d, as the atmosphere isn't that thick, making it mostly 2d; travel distances is far greater than the height delta, so height is *tactical* not *strategic* or *logistical* in scale).

...

So mixing sci fi, age of sail and fantasy tropes...

Solar Wind should be a thing. This shouldn't flow strait out from a sun (just tend to). The Solar Wind should form storms, hurricanes, etc.

The Gyre should be the source of orbits. In a solar system, it forms something like a whirlpool, and planets flow on it. Around each planet produces a local whirlpool. The gyre basically replaces gravity for orbital mechanics.

I'd imagine the Gyre forming a flattened donut around each stellar body. This produces a two-surfaced membrane at the edge of the Gyre you can pilot ships on. Planets would form a sub-gyre on the gyre of the star, a sort of pinching-off of the solar Gyre, and the planetary Gyre merges into the solar Gyre at the edge.

The Gyre itself is inhospitable to life (at least planet based life); so your ships stick a sealed hull into it. Monsters do come out of the Gyre; they are akin to sea monsters.

The surface of the Gyre is irregular, and it has waves and currents.

The solar wind blows over the surface of the Gyre.

This makes a solar system have a top and a bottom side (to the Gyre); crossing from one to the other requires a planet or similar, and braving the rough whirlpool around each. Asteroid belts would also produce Gyre effect, pinching the solar Gyre together and forcing ships to go through it. Asteroids can be as common as you want, but the Gyre itself will have nasty topology through them.

We can make up a name for the substance of the Solar Wind and the Gyre. Aethyr is good for the wind. Make up a word or steal one for the Gyre (Philostrem?). Then you can talk about how Aethyr storms cause Philostrem to scatter above the Gyre (aka, rain).

Ok, once you have this, your ships velocity is relative to the Gyre they are riding on, and the Aethyr they are being pushed by. Approaching a planet is tricky, because the topology of the Gyre makes it harder (You have to detatch from the Gyre to land on a planet?), and the Aethyr wind tends to be lower in the planetary Gyres than further away.

You can also shrink solar systems; they are more than a bit too large. Think in terms of travel time. Velocity is relative; but you do want ships going to another planet and those returning to interact, right? If your distances are too large, then they will pass by each other at insane velocities.

For ships to meet each other going in the opposite direction between planets, there needs to be local bottlenecks at which they are traveling relatively slowly (in opposite directions), or not that much distance between planets. To steal from orbital mechanics, Holtzman gates might be the name for the bottle neck places that going to and from a planet you have to travel through. There can be multiple Hotzman gates, and they are places where the Gyre isn't moving fast in any direction, and the only safe way to cross from one planetary Gyre to another.

So the topology I'm imaginging is a big solar pancake "gyre" with an (overall) whirlpool flow. This solar gyre is pinched off at each planet, which has its own whirlpool flow. Between planets there are fast-moving geodesic flows. These flows meet at Holtzman gates, knots in the gyre, that allow you to transfer from one geodesic to another.

The geodesics change as the planets orbit. There are well known ones, and more dangerous and less stable ones, you can take; this means that travel looks like a (combinatorics) graph. And Holtzman gates provide bottlenecks along paths between planets.

This gives you asteroid sholes, a reason to risk going through asteroids, fast long distance travel (along geodestics), Holtzman gate "nodes" on your travel graph (where you run into other travelers), no ability to ram planets, space-going vessels that look like ships and harness the solar wind. Interstellar geodesics that go extremely fast can explain why you can go far distances; the galaxy itself can produce a gyre, on top of which stars puncture it, or even multiple gyres (and going between gyres is dangerous and difficult).

And it uses a mixture of science fiction, real space and fantasy words.

I love this, and will immediately begin to create sailing and navigation rules for it. It has an overall elegant simplicity, and the potential for complexity. (Imagine sailing the skies of Saturn!)

[Tvtyrant]

You can always go very euclidean: objects in space are essentially marbles rolling around the inside of a nested series of invisible spheres. Ships traveling on the spheres themselves don't fly through space but ride along the frictionless surface at incredible speeds, and have to use magic to slow down when they want to transfer back to a planet. Getting between spheres means riding up and down thin tubes connecting the spheres.

[Quizatzhaderac]

Since realism seem to be unimportant, may I also suggest smaller planets/worlds?

Sci-fi worlds are usually metaphors for nations at most, often for small towns or isolated tribes.

So smaller worlds, relatively closer, and ships can only move at a small speed relative to the aether, and the aether never sends hyper-kenetic objects into planets.