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[FATE/Diaspora] Jovian Chronicles – Hard SciFi and Purple-Haired Mecha Pilots


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Years ago, a younger and more naïve Xashren bought the Jovian Chronicles 2nd Edition PDF. I read it over, got excited about it, got my friends excited about it, and became determined that we would play a game of it. Then we took a long, hard look at the space combat and realized that we didn’t want to deal with vector mechanics in our pew pew shonen anime roleplaying.

But the dream never died. Every system even vaguely capable of sci-fi action we’ve encountered has been given the “But can it run Jovian Chronicles?” test. We’ve had a few hits, but nothing that really felt right: Wushu can run anything (and I love it dearly), but it didn’t have anything for my mechanics-loving players to sink their teeth in to. Burning Empires’ mechanics are too deeply tied to its setting to do what we were looking for, despite having a conflict system (Firefight!) which is just perfect for abstracted, mechanically-interesting-without-being-overwhelming armored combat. Hell, we even looked at Shadowrun for about five seconds before making the sign of the cross and locking it away in a dark, dark place.

I picked up Diaspora in December and knew that I wanted to do something with it. I had read through previous FATE games while looking for an alternate system under which to run Exalted, but Diaspora was the first presentation of the engine that sank its hooks into me and wouldn’t let go. Then, inevitably, I gave it the “But can it run Jovian Chronicles?” test, and found to my surprise that there was no reason why I couldn’t.

A brief comparison:

Diaspora models hard science fiction. Its implied setting is one in which inter-system FTL is impossible, artificial gravity is produced only by rotating stations or the acceleration of a moving starship. That movement is achieved through the ejection of reaction mass. Combat between ships is as much about positioning and electronic warfare as it is about big guns.

Jovian Chronicles posits a somewhat softer version of sci-fi, but it’s still harder than most. FTL of any kind is impossible; artificial gravity is, again, possible only through rotation or acceleration of skyscraper-shaped ships. Reaction mass ejection propels ships, although there’s some handwavey “science” about mass drivers and plasma combustion chambers. While combat between starships is mostly defined by stationary vessels slugging it out at unrealistically close ranges with giant lasers and kinetic weapons, a surprising amount of thought is given to making this genre requirement at least vaguely plausible. Hell, there’s even a section which notes that “By definition, a good engine makes a good weapon,” a classic hard sci-fi trope.

Then there are the anime mecha. Welp.

This was a serious stumbling block for a while, until I got all the way through the book and found the Armor Design section at the very back. It all fell into place when I realized that the mecha anime genre doesn’t treat an exosuit as a vehicle, or squads of mecha as an analog of infantry or mechanized combat: when combat matters, it is a personal engagement between a handful of pilots, with platoons of exploding exos in the background purely as color, giant warships as stages for personal combat instead of active participants, and the suits themselves as tools which are nothing more than a way to augment a pilot’s natural talents.

Mecha are just armor, and they need no more mechanical representation than Diaspora provides. Mecha combat doesn’t need a special system or even Diaspora’s Platoon rules: it’s Personal scale all the way.

To make a long story somewhat shorter, we decided to try a Jovian Chronicles game with the Diaspora engine, cleaving as close to the rules-as-written as possible with minimal conversion ala Kordeth’s Diaspora Star Wars. What follows are the fruits of an impromptu cluster generation and character creation session. We’re all new at this “FATE” thing, so we’re open to comments and suggestions.


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“Cluster” Generation: Sol System

As with Unshaven’s cluster generation for Cowboy Bebop and Planetes, we found ourselves having to represent an established setting in Diaspora’s cluster mechanics, complicated by the fact that we were building not a series of star systems but individual planets. The format below is shamelessly stolen from Unshaven’s thread.

As mentioned above, we’re open to suggestions about all of this. Our Aspects in particular need work, as this is the first time we’ve ever dealt with them and the whole thing came together in only a couple of hours.

Mercury: T1, E-3, R-2
Mercury is on par with most of humanity, technologically: they can explore and exploit the system without too much difficulty. T1 seems appropriate, but T2 explicitly mentions that commercialization and extensive trade becomes feasible at that level. Mercury depends on its trading ships, but it is clearly technologically inferior to, say, Venus or Jupiter, and it doesn’t seem appropriate to put those planets at T3. Thoughts?

The surface of Mercury is a nigh-on-uninhabitable hellhole, inhabited by rotating crews of engineers who live in underground complexes and manage the vast power relay stations. Everyone else is forced to live in orbital stations, hiding from the killing Sun in the planet’s shadow. E-3, anyone?

Mercury is not a sustainable environment: surface mining isn’t feasible and station-borne hydroponics can’t feed its population of 21 million people. All that keeps Mercury afloat is its Merchant Fleet, to which all Mercurians must contribute a few years of their life. As bad as that sounds, I’m leaning toward R-2 because the corebook mentions that it does have a “few” exportable resources, and it doesn’t give any indication of just how rapidly Mercury would degrade if trade fell apart.

Mercury’s Aspects
Absolute neutrality
Lives or dies by the Merchant Fleet
Too close to the Sun

Venus: T2, E-2, R0
Venusian technology is cutting-edge. Their ships, exo-suits and attendant technologies are far more advanced (not to mention numerous) than anyone realizes. In a traditional Diaspora game I would hesitate to put them above T1, but the need to represent their technological superiority over the rest of the solar system means they get bumped up to T2, possibly T3 if we end up shifting the technological baseline from T1 to T2.

Venus is in the process of terraforming, but the population still needs to live in protective domes and the world outside is both poisonous and dangerously hot. E-2 fits.

The corebook notes that Venus is self-sufficient despite their importation of foreign electronics and machinery, which continues in order to maintain a façade of weakness and dependency. That said, they’re not exactly a net exporter. R0, “Sustainable,” feels just right.

Venus’ Aspects
Ruled by corporate city-states, but the Bank holds all the power
Fabulously wealthy
Not as weak as it looks

Earth: T1, E-1, R2
Technologically, Earth (or at least CEGA’s portion of Earth) is capable of traversing and exploiting the solar system and has managed to assemble the setting’s largest (albeit least advanced) fleet. They don’t quite match Jovian or Venusian technology, but they’re certainly capable of holding their own: T1, “Exploiting the System,” seems to fit.

Jovian Chronicles Earth is a mess. Ravaged by environmentally-destructive wars, plagues and neutron bombs, much of its population resides in massive government-built arcologies rather than try to eke out a living in what the corebooks calls a “half-poisoned biosphere.” That sounds like E-1 to me: “Survivable,” but not pleasant by our standards.

Earth is a large, resource-rich planet all on its lonesome, but CEGA’s Earth also ruthlessly exploits Luna’s resources and anything it can get from the Orbital colonies. It’s also the only place in the solar system where you can stick a seed in natural ground and watch it grow, making it the breadbasket of humanity. The corebook also notes that Earth snatched up quite a lot of prime real estate throughout the solar system before anyone caught on to how dangerous they were, and everything they acquire gets funneled back to the homeworld. On their own, Earth might be R1, but with everything they’re getting from the rest of their holdings, I figure R2 is more fitting.

Earth’s Aspects
Slowly recovering from the Fall
The birthplace of mankind
Our only garden world

[I’m not sold on these aspects yet: the second and third feel like they should be merged somehow, to free up a third aspect directly relating to CEGA.]

Luna: T1, E-3, R1
Luna is the gateway to Earth and home to some of its most advanced exo-suit factories. That said, its technology is CEGA’s technology, no more and no less: if Earth is T1, then so are Luna and the Orbital colonies.

Luna’s barren surface is hardly an ideal environment for life. The only thing the Selenites have going for them is solid ground under their feet and a bit of water-ice, but it isn’t much: E-3.

Luna is rich in natural resources, providing Earth and the Orbitals with “much of their raw materials.” Impressive, but they can’t keep much of it. R1 feels appropriate.

Luna’s Aspects
Subservient to CEGA
Bastion of the CEGA fleet
No-nonsense mining world

[None of us are terribly happy with the third aspect, but we couldn’t find a better way to phrase the Selenite attitude toward self-sufficiency, organization and hard work, and we were running out of time.]

Mars: T1, E-2, R0
A series of long and brutal civil wars has left Martian technology stagnant and underdeveloped for decades, and they are only now beginning to pull themselves free. They’re allied with Earth and are presumably at technological parity with them, but the corebook doesn’t give us much to go by. We assumed T1.

Jovian Chronicles Mars has been terraformed, and that terraforming is going rather better than on Venus, but habitation domes are still necessary. E-2 makes sense.

Mars only exists as it is now because it was self-sufficient enough to throw off Earth’s shackles: it is clearly “Sustainable” at R0, but not rich enough to make the jump to R1.

Mars’ Aspects
A divided world
Barely relevant to solar politics
Unparalleled bioengineering expertise

[The Martian aspects need work.

I’m quite tempted to replace “A divided world,” meant to represent the divide between the totalitarian Martian Federation and the anarchic, Wild West-influenced Free Republic with the section header from the Jovian Chronicles corebook, “Steel Gauntlets and Robot Rodeos.”

“Barely relevant to solar politics,” while mostly true, feels like a flat Aspect to me. I can’t put my finger on what’s wrong with it.]

The Belt: T0, E-3, R-3
The asteroid belt is inhabited by nomadic spacers with no support networks who barely keep their jury-rigged ships and tiny colonies held together with duct tape and prayer. These people aren’t “exploiting” anything, they’re just surviving. Still, what technology they do have is considerably more advanced than present-day Earth’s T-1, so we’ll call it T0 and be done with it.

The only reason the Belt is inhabitable at all is because belt nomads are stubborn bastards who somehow manage to claw out habitable domes or pressurize the interiors of asteroids. This is a harsh, harsh environment: E-3, “Barren World,” explicitly mentions an asteroid belt, so that works nicely.

The asteroid belt is full of precious mineral resources, but the nomads are so few that exploiting them on a large scale is impossible. Everything from food and water to fuel and plastics need to be imported: the belters have “Multiple Dependencies,” so R-3 seems fitting.

The Belt’s Aspects
Fiercely independent to the point of anarchy
Constant struggle for survival
Jury-rigged engineering

Jupiter – The Olympus Stations: T2, E-3, R2
The Olympus Stations in orbit around Jupiter itself and on and around its satellites form the heart of the Jovian Confederation. Jovian Chronicles makes a big deal out of the Confederacy being the most technologically advanced civilization in the solar system, possibly equaled by Venus militarily. They are well past exploiting the system and on to doing it in style. For our purposes we assumed that Jupiter and Venus were close enough to put in the same tier, which makes Jupiter’s Olympus Stations either T2 or T3, depending.

The Jovians live in orbitals around Jupiter, a few of its satellites, and on the surfaces of Ganymede and Callisto. This is a tough call between E-3 and E-4, as I’m not sure whether two small satellites with solid ground are sufficient to bump it to E-3.

Jovian gas harvesting could supply the entire solar system with fuel if properly exploited, while Europa and Callisto have nearly limitless supplies of water, a resource present in quantity in only one other place in the system – Earth. Jupiter needs mineral imports from the Trojan States, but it certainly doesn’t have any trouble paying for them. R2 fits nicely.

Jupiter’s Aspects
At the forefront of spacefaring technology
”We’re the good guys”
Heart of the Confederacy

[The first aspect needs to be tweaked or strengthened somehow, but I rather like the other two. Thoughts?]


Saturn, Titan and the Trojan States are up in the air at this point, as we ran out of time to complete them. I need to run for now, but next up: the system map, characters, and my first attempt at statting up an exo-suit. In the mean time, any thoughts?
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Brad J. Murray

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Validated User
Very cool, Xashren. I'll note that this is exactly what I recommended in another Diaspora + mecha thread and I still think it's pretty much ideal. Not because of emulation details per sé but because platoon is the scale that mecha operate, so that's where they should be emulated.

Just for contrast, though, I could also see it run with the space combat rules if pursuit was more interesting than the multi-unit clash that platoon scale implies. I might even be tempted to use both -- space for one-on-one and platoon for big fights.
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