Imagine a distant future in which humans’ descendants have scattered throughout the stars, settling wherever they can.

Some planets and moons are resource-rich paradises, while others are barren wastelands with little to offer other than common minerals and metals.

In sci-fi, spacefaring peoples often war over things like water—necessities that we take for granted here on Earth. In post apocalyptic settings, conflicts arise over food, water, gasoline, weapons, and shelter. And then there are the valuable rarities, such as the spice melange in Dune (and of course the vibraniums and unobtaniums and all the other handwavium plot devices).

Obviously, interplanetary and especially interstellar conquest is unimaginably resource intensive, and therefore uncommon. And obviously, demand will depend on what’s available in any given solar system. Some planets or systems will lack certain fundamental materials, whether it’s wood or wheat or aluminum. And of course, habitable planets are themselves valuable rarities worth fighting for.

But here’s my question:

Which materials are most likely to be in high demand most often among future spacefaring peoples—so much so that the demand for them results in interplanetary and/or interstellar conflicts, whether petty piracy or all-out war?

Could it be aerospace materials? Rare earth elements? Precious metals such as gold and platinum? Radioactive metals such as uranium and plutonium?

Even if water, food, and oxygen are in much greater demand, I’m curious which rare commodities might become targets. Of course, this depends in part on the cultures and the technological development of the diverse populations in question, so feel free to use your imagination.

I realize that some of the materials that are rare on Earth are abundant in outer space. Asteroids, for example, often contain tons of precious metals, and let’s assume that some colonists mine them.

Let’s also assume that at least some of these civilizations (namely those staging attacks or invasions) are capable of FTL travel. Given the staggering distances between stars, I’d imagine that interstellar warfare would be even more unlikely without it, but maybe not.

Easily transferable energy is probably a prime candidate, but I’m not sure what that would look like to a spacefaring civilization (barring antimatter or something like that). Probably not fossil fuels or even chemical propellants, though that’s an intriguing thought.

Anyway, thanks for any ideas.

  • $\begingroup$ A historically powerful one: Lebensraum? Or "building a Dysonswarm is tough work. Yours looks fine and functional, thanks". $\endgroup$
    – Demigan
    Mar 1, 2020 at 11:03
  • $\begingroup$ Do "people" count as natural resource? Reasonably you want to make any aliens you meet extinct before they can do the same to you. Or at least enslave them so nobody else can use them to attack you. $\endgroup$ Mar 1, 2020 at 17:12
  • $\begingroup$ They do, yes, but to reframe my question, I’m curious which inanimate material resources might create conflicts. I gather that even rare materials are abundant in space and that conflicts will almost always be over territorial conquest, slave labor, and/or ideology. And also that localized conflicts could be fought over virtually anything, because it all depends on what’s scarce and what’s in demand. Any conjectures regarding what might be valuable to interstellar conquistadors would be cool, though! $\endgroup$ Mar 2, 2020 at 5:47

11 Answers 11


TLDR: I first discuss why I think some common tropes are nonsense (if you want to be hard-scifi. If you want to use handwavium, then the whole question is anyway nil), before trying to construct some alternatives. Also I exclude local versions of resource scarcity like The Expanse, because you want interstellar conflict.

Common tropes:

I feel like it is very hard to justify conflict based on resources, once your civilisation reaches space, and possibly even FTL travel.
When you have the $\Delta v$/spaceship fuel available to go up and down a gravity well as much as you want, you can literally mine out whole solar systems and bring the material to your orbital construction sites, or even down the gravity well, for general production.

As there is literally everything in space, you wouldn't have trouble finding the material you need.

  • Water and Oxygen. No problem. Drill up some asteroids and moons, water is one of the most abundant molecules in the universe (or at least its constitutents are). Same with oxygen, just electrolyse the water. This kills already any Alien invasion storyline based on scarcity of water. Scarcity of habitable planets might still be a reason, but seems to me more and more like a cheap plot devices, the more exoplanets we discover.
  • Building materials of any kind shouldn't cause trouble either. In order to build structures, you will take whichever material is available (think about building materials on the Moon or Mars, you sure as heck wouldn't use concrete and wood) and therefore by definition, any crafty Civ will come up with smart ideas to make the abundantly available Rocks/Metal + Energy into buildings and structures.
  • Rare earths/Metals: Same as building materials. Stellar nucleosynthesis might not produce as much of this stuff as water, but planet formation processes are exceedingly efficient at concentrating those materials in planets/asteroids. Just grab them.
  • Rare handwavium to power XYZ: This is a lazy trope and not worthy of any discussion. Literally no work goes into a setting like in Avatar to justify the main driver of the story.

Of those issues, only an enourmous population size would require to strip-mine entire solar systems and possibly clash with the strip-mining of other Civ's target systems, creating scarcity and conflict. But this also seems like lazy writing to me, as it just projects Earths history onto space. Not very mind-bending.

Trying to fix some of those issues:

  • Naturally very scarce elements 1. Nucleosynthesis in the universe naturally produces elements beyond iron/nickel in very small quantities. If your Civ finds an important usage for fissionable material, and you handwave some geologic reason why Uranium is only concentrated in Earth-like planets with tectonic planets (siderophilic/siderphobic separation), you might have a setup. Make those planets even rarer than regular 'habitable' planets and handwave away why your Civ did not develop nuclear fusion (which uses the abundant hydrogen), so that it needs fissible heavy elements for energy generation.
  • Naturally very scarce elements 2: This borrows from Dune, but a bit more hard-scifi. Use fissionable elements for some kind of sophisticated cancer-killing longevity treatment. This would have an obviously massive demand in your Civ, as everyones super-long life would be at stake. I'm no medical expert, so this might still seem like lazy writing (why not do away with the cancer via genetic enhancments/ implants? Or maybe the implants require little nuclear fission batteries to function, because fusion only works on a large scale...). But the latter idea seems too much like Asimov-era writing to me.
  • Naturally high concentrations of hydrogen could be hard to get: Sure, everything is in space, but it might be prohibitively expensive to concentrate it, in order to work with it. A good candidate element for what a Civ needs in large quantities is hydrogen. Hydrogen for energy generation is abundant in the universe. But how to get it in sufficient quantities? The heavy radiation output of your central star might not be worth it as it kills your mining technology, no matter how sophisticated your shielding and AI brain is. And on the other end, there are nebulae with free hydrogen gas everywhere, but this gas is very sparse. Large machines and timespans might be needed to concentrate that hydrogen and bring it home, making it expensive. You would want to go into the most dense star-forming regions to speed this up, which might create some territorial conflict.
    Additionally, when Civ A (space-capitalists) starts mining gas in the local cluster to fuel their growing hydrogen fusion economy back home, Civ B (space-moralists) gets super-offended, because the mining of gas in star-forming regions on this scale prohibits future solar systems to form and hence life to evolve. Boom, religious war. I realize now, this has been done to some extent in the Homeworld game series.
    This setup however would have its own problems to handwave away: Why not mine the gas giants in the home solar system? Why not icy moons?

Beyond resource scarcity:

Other commentators and answers have hinted at that this might not be the only way to generate conflict, but I want to formalize this a bit more:
Let us think about the way our economy works. We learn in school (and that's about all I know about the economy, so again, there's a chance here that I'm suggesting what other might see as lazy writing) that our economy can be divided in primary, secondary and tertiary sectors. Those represent resource extraction, production and services. All scenarios I discussed so far were focused on justifying the scarcity of resources in the primary sector, and assuming alien economies would work similarly, for the lack of differing data.

If there is a chain of Civs that has their own little trade secrets each concerning the secondary and tertiary sectors, this can always be a cause for conflict. Imagine Civ A sends some basic resource to Civ B, using them as blackbox-turned-trading partner, and what they get back for it is supercool high-temperature superconductors, that Civ A has no idea of how to manufacture. Same for services in the data analysis sector ("We have the best AI's to help you oppress your population! But they need maintenance cough " with bonus moral conflict for the Civ that sells the AIs)

I feel like in those trade networks, it would be very easy to generate scarcity for political reasons, which would spread into conflict between Civs. But you would then have a harder time to justify the existence of the trade relation itself (why does Civ B need 'basic resource' in the first place? And why do they think selling Superconductors to Civ A is a good idea?) Maybe the trade relations exist only for Civ B to have political leverage in the first place, and at some point Civ A doesn't want to cope with that anymore. Boom, war of economic freedom. But also Asimov has done that before.

  • $\begingroup$ if water and O2 are easy to get by elctrolysis of water then H2 surely has to be too $\endgroup$
    – jk.
    Mar 2, 2020 at 16:36
  • $\begingroup$ @jk. True. But depending on your scenario, your icy moons and gas giants might be mined out of usable hydrogen, or simply your economy might have such hunger for $H_2$ that you immediately leave your solar system alone, and go much bigger in scale, to mine out some nearby star forming regions (containing up to hundreds to thousands of solar masses of hydrogen that hasn't collapsed into a gravity well yet). $\endgroup$ Mar 2, 2020 at 17:07

Chemically speaking, scarcity should be close to a non-issue if you have a vast interstellar civilization. If humanity were focused on extracting as much value from our Solar System as possible, we'd need populations best expressed in scientific notation to use it all within several millennia, and eeven that requires quite literally astronomical levels of wastefulness. Add more systems, and anyone who winds up with a genuine chemical or mineral scarcity is not likely to be in a good position to go to war over it.

Since simple, naturally-occuring elements are unlikely to be war-worthily scarce, that leaves complex, artificial resources. Try as you might, you can't reverse-engineer the famous cheese produced by the dairy cartel of Tau Ceti, and the genetically engineered superpeople of Vega went all isolationist and no one who figures out what tweaks they made lives to tell, and we're sure that there are great secrets locked away in the archives of Titan, but they are protected by billions of cyborg warrior-monks who insist that they remain inaccessible to outsiders.

In short, life, skills, and information are the resources that could plausibly remain poorly distributed.

  • $\begingroup$ Or there might be several types of handwavium available only in select systems. Being handwavium it does not have to obey the regular rules. $\endgroup$ Mar 1, 2020 at 14:16

/Which materials are most likely to be in high demand most often among future spacefaring peoples/

Spacefaring peoples.

The people themselves are the resource. They are scattered through the stars. If you can convert these people to your subjects, you can get them to pay tax. If you can convert these people to your religion, you can get them to tithe and your gods will smile upon you (and them too, of course).

If you control a people, you control what they have and more importantly what they might have.


We're excluding wars based on ideological motives, right? Then:

  1. in local conflicts, whatever the attacker is in short supply of. And this can vary wildly

  2. as a source for potentially globalized conflicts:

    • may be immaterial - like access to other worlds to colonize
    • in case of some material or technology - anything that allows obtaining and controlling huge (ever increasing) amounts of energy. If you have enough cheap energy that you can control, you can obtain anything you want. Even FTL (assuming it it possible in any way) will require immense levels of energy.
      Whatever is needed for energy management will also likely to change over time.


Iridium is one of the rarest of the rare earth metals. While the spot price of iridium doesn't seem that impressive, that's mostly to do with our primitive technology. It has numerous industrial uses, especially in high-temperature applications (think: spacecraft engines). It is also one of the densest metals, which is likely a factor in why it is used as a mirror in X-ray optics.

So...imagine that future ships use beam weapons due to their speed, and nobody is foolish enough to use long wavelengths like visible-UV range. No, they are going to go for x-ray to gamma ray laser batteries. Unfortunately, the "force field" style shields common in SF aren't realistic. To defend against a beam weapon, you either need a lot of mass (bad for a spaceship), or a material that deflects the beam well. If iridium is the metal of choice for warship beam armor, then that will create a pretty natural demand all by itself.

Economic Reserves

Oil reserves are always stated in multiple categories. Proven reserves are reservoirs that have been tapped and mapped and we know they are there. Whereas, economic reserves means the oil that we can pull out of the ground cheaply enough to sell it at a profit. The main problem with iridium is that a lot of it is locked away in the planet's core. It may be that spacefaring civilizations are willing to rip apart a planet to its core to get at the nice shinies, but if there is some kind of religious prohibition for stripping planets to their bones, then you are left with the economically recoverable reserves. Right now, global production of iridium is less than 20 tons/year. I can imagine that being used up pretty quickly on just a few battle cruisers. Of course, we are likely not extracting it at nearly the rate that we could be. But also imagine that not all planets have abundant iridium, or are even rocky.

Note that a star-hopping empire will need hundreds to thousands of warships to defend its interests, especially against competing empires. This could easily create demand for millions of tons of iridium. Due to its very high heat resistance, it may also become a critical component of ship drives or power plants (any heat engine's efficiency is determined by the operating temperatures, so the hotter the plant, the better the energy usage). If iridium becomes the resource bottleneck for both warships and civilian transports, then obviously the empire which controls the most iridium controls the most space, period. Capturing more iridium deposits literally strengthens your navy, as well as your ability to expand territory.


I would say very rare galactic/interstellar elements/resource.

For example in the movie Avatar, while not on an interstellar conflict but the driving force of it is the very rare metal found in there. it costs 20 million dollars a kilo, it funded the whole expedition.

Same with Aliens, an interstellar conflict due to the need to weaponize/control the Alien hives by humans. It can be considered that the aliens while an adversary but also a resource that humans(Weyland-Yutani) wanted to have.

Also with Dune, the spice was so important that who ever had the planet under their thumb would rule the whole universe either by proxy or by ascending as a hegemon among the stars. And hoarding the same stuff could escalate conflicts into intergalactic one. Stopping the supply of the said stuff could have everyone cooperate on whoever controls it.

The Spice Must Flow

That said, so as long as the supply for the said very rare element/resource is within the demands of the consumers, no conflict would ever arise, not until the said supply runs out.


I would say controlled information.

In an interstellar civilization where raw resources aren't an issue and you can synthesize more or less anything you know how to make, information is king. If Dune were more hard sci-fi, what's stopping people from mass producing synthetic Spice? The Guild/Mentats/Bene Gesserit all would need to tightly control access to the stuff so that no one can reverse engineer it. Extend the example and now there are controlled technologies that different systems are trying to hoard for themselves to gain advantage over the others. Espionage would be a huge and constant issue - maybe even escalating into all out war to get access to some especially juicy tech before the originators get too far ahead with it.

Other options would be things like the need for massive amounts of resources for huge mega structures, or ideological conflict (political or religious) where one or both sides feel the need to convert or extinguish their neighbors - maybe for fear that their neighbors will do the same to them.

  • 1
    $\begingroup$ Your point about synthesizing spice has been addressed in Dune itself: The reason nobody can synthesize it initially is handwaved away as 'super-complex molecule and no one really understands how it works'. Later in the story people learn how to synthesize it. But your point about techs remains valid: If you get your hands on alien tech through legal trade, you might still never be able to reverse-engineer it, because it originates from a different form of thinking. Hence scarcity. $\endgroup$ Mar 2, 2020 at 3:27

Warp jump points.

You need to jump on a given Warp Jump Point since the technology to pierce the distance between two points eats exponentially more energy on any other place.

Want to control this sector?
Place a military vessel close to the WJP and enforce which side gets trade.

Want to engage in some Privateering? wink wink, nudge nudge Use a WJP that hasn't been declared.

There you got conflict of interests to fuel ton of stories.


I think interstellar conflicts — including piracy and privateering — would still occur over the same things, but for different reasons.

I think elemental matter and simple molecules will be widely available outside gravity wells. So water, titanium, oxygen, raw elements or simple molecules will not be expensive.

Specific forms of some materials like diamond could be expensive since its unlikely to find a lot of diamond floating around nova — there has to be some but not chunks like we find on planets. Same thing for ruby and quartz and etc — materials with rare stoichiometry. Assuming that they are engineeringly useful then could be valuable enough to fight over

Complex hydrocarbons — petroleum to methane — because its a feedstock to make so many useful things and its formation is energy intensive. While the gaseous forms (Methane) look to be widely available, the more valuable and larger molecules only seem to occur on planets with life so are going to be very rare.

Proteins, carbohydrates, sugars — since they depend on some sort of lifecycle — could also be rare and valuable. They might be valuable enough that killing and processing aliens into foodstuffs could be a thing. Or, there could be crypto cannibalism — soylent red could be the democrat’s plan for republicans, same as soylent blue.


It's not for the resources themselves, but for the rivals not to obtain them

Resources are actually not scarce, they can be easely found basically everywhere. The problem is that every civ absolutely does NOT want the others to outgrown them in terms of raw war capacity, science, population and region presence. This leads to a neverending spionage and sabotage missions, ocassionaly all-out war to keep their hands away from the resources.


Living space.

Seriously. You're postulating a scenario where moving people across interstellar distances is cheap enough to be worth doing, and you're postulating a scenario where moving ENOUGH people across interstellar distances to fight a war when they get there is cheap enough to be be worth doing, so:

The most valuable possible resource for a given species is planets that they can live on without major terraforming and/or environmental protection. Every other resource you can think of is WILDLY abundant by comparison.

I mean, that was the entire point of World War 2, at least for Germany. Hitler's objective from the beginning was to take all of Eastern Europe and depopulate it so that good German civilians could fill it back up. The invasion of Western Europe was only necessary because France and the USSR had a mutual defense treaty, so Germany was going to have to fight them both anyway. Better to knock France out first and then go after the USSR. Humiliating France in retaliation for the Treaty of Versailles was just icing on the cake.

Sure, there were the Caucasus oilfields too, but the reason the German invasion of the USSR failed was because when Hitler was forced to choose between wiping out Stalingrad or bypasssing it and taking the oil, Hitler refused to leave Stalingrad standing.

So, even here, today, on Earth, good territory is often the most important resource to be had. Out in space, that will be even more so.

  • 1
    $\begingroup$ With each star having several planets around it, possible targeted genetic mutations allowing to live everywhere, why would living space be scarce? Als -1 for a gross misrepresentation of the causes of WW2. 'Lebensraum im Osten' was a minor ideological detail and by no means an economic necessity. The invasion of France being only a bonus? The two-front war being an accepted fait accompli from the start? I don't know which history books you read in 'Murrica, but they sure seem weird ones. $\endgroup$ Mar 2, 2020 at 3:38

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