First I love the whole desperate infantry squad against a sea of trouble premise of so many stories. Even when some of them is set in the future. There is the rub.

How on earth would I have a setting of such advanced everything and then can have human infantry running around doing stuff?

Now I know that for example Warhammer 40K has it's own rules about that, magic and no AI and bio-engineerd soldiers and all that, but honestly I think for the most part human infantry is just too fragile and useless in most settings and so won't be actually used.

So when I think of galactic empires fighting other states I automatically assume space combat and some planet based combat. As much as it hurts to remove the infantry from the equation I think it only makes sense to completely relay on machines to fight for us once we reach a point that allows it. Right?

I imagine that our tanks, ships, jets, and drone are almost perfect in principle that in the future we can just improve on them not make new things.

However you are the ones solving this problem so it is up to you even to redesign tanks.

Now I welcome challenging this idea of making infantry obsolete. Or why would these machines be all rolled into one or several main one.

However an important point is that the theory is that they need to be practical and very flexible. If you have a system that produces perfect water world tanks but you reinforce it with armies mainly adapted to desert world then you are at a great disadvantage. But all reasonable arguments are welcome .

General points.

  • Manufacturing capabilities is not a problem. Humanity controls several star systems. The closest example I can think of is the the Forge Worlds and Industrial Worlds of warhammer 40K. Just an entire planet devoted to creating stuff. Raw materials are transported from where they are and the planet is wholly devoted to making whatever it makes. Toothpicks or void fighters.
  • There is no true artificial intelligence. Instead it is AMI as in advanced machines intelligence and it is basically AI like but not human levels yet. It is capable of making human levels tactical decisions and has access to vast data bases and small in size, fist sized. It is very much like how we can program stuff nowadays. It does not prioritize it's own existence or anything like that. Thought it is obviously made to save energy and the machine it is in. It's cognitive performance across the board is like humans. It can aim better and feels no pain...etc but also it is capable of making the military and tactical decision that soldier and minor officers make. None are used for actually planning wars but they are used to assist the calculations and producing scenarios...etc
  • Humans are not looking to counter one particular enemy. Think of this as the galactic equivalent of main battle tanks. You are making just one basic model to fit all rules and fight in all different scenarios.
  • We have very powerful reactors, we can use them to power tanks or ships or whatever.
  • Anti gravity technology exists. But should be used only when it does make sense and adds actual benefits to the machine rather than lets just add it there.
  • Energy shields are a thing. I can't make a science fiction setting without one.
  • The general military principles of today still carry over. Including the less the cost the better, the more robust the better, the simpler the better...etc.
  • We can manipulate materials to the levels of Mass Effect and Warhammer 40K. However since there are finite resources the more you use the more it needs to be justified.
  • An important point about manufacturing is that humanity has manufacturing machines and entire planets devoted to that. Humans don't come into it. But even machines can only produce so much as the transportation of materials and building time and shipping time...etc are limited as we all know. So an idea of a drone that costs 200 hours but only provided 10% better performance than a drone that takes 150 hours to make is not a good idea as far as we are concerned.
  • Battlefields are a problem. Making an machine that runs in the desert is different from one that runs in ice fields. So all machines must be able to preform in any planetary environment. An incredible feat by our current standards but this is the future.
  • These limitations are more like our own except they are turned to 11. For example we can add more and more stuff to fighters but that increases the cost and time and means that a loss of one is a problem. So a compromise, that is the name of the game, is needed here. So I'm looking for a realistic take on the idea not crazy fancy unrealistic stuff, I can come up with that on my own, but stuff that is grounded in reality and would be natural for a human galactic empire to adopt as the manifestation of our military will and the tools of furthering out political agendas.

I fully understand that a even several machines might be difficult but I hope it does not boil down to 314 types of different machines as that does not help. Again I think the idea of limiting the main fighting machines to several types makes more sense so that the human fleets are flexible enough to reinforce whatever human colony.

I personally thought of a couple of things.

  • Anti gravity, plasma cannons, tanks with energy shields and anti air missiles. Secondary weapons are a must and obviously has way better targeting and detection technology. The main weapon of the future and can be adapted further to function in the most extreme environment
  • Small drones, a meter by a meter, with good armor and a main weapon. used by the dozen to clear buildings and be like infantry.
  • A spider like firing platform that can function in any environment and has the equivalent weapons of a light tank but also flexible enough to be used in urban or jungle combat. laser weapons and some plasma one.
  • Armed transportation to transport that.
  • All have AMI that is equivalent to current human performance and is connected to other machines in the area to coordinate the operation better. But they can also function on their own if needs be and would just follow whatever plan is made.

So the theory is that an appropriate number of those machine are deployed depending on the context of operation. Then a small group of human officers command the machines to achieve the desired outcome of the operation.

This is just an example of how I imagine thing can be. It can changed, challenged, or outright removed. Just a bit of context.

So. What sort of machines can you make that satisfy all the previous points?

Edit: I appreciate all the input regarding the space ships or combat aspect. However I only want ideas on ground, that is inside a planet or equivalent thing, machines.

Also what people seem to be missing is that equal powers exist and you can't completely abandon "ground" combat.

For example you have fleet of X powers arrive and say we will destroy the planet. But your enemy has a fleet of equal power that will oppose your own fleet.

Again this is just how actual world military thinking is. Countries with nukes, nuclear submarines, best air-force and overall most technology still use infantry fighting vehicles and still arm humans with automatic rifles and even pistols and knives.

Anyway I don't want this to be about space combat or ships as it is something completely different. Nor I think it a frame challenge because you will still have fighting machines on the ground.

  • $\begingroup$ Any terrestrial environment you mean? $\endgroup$
    – DKNguyen
    Commented Oct 2, 2020 at 21:12
  • $\begingroup$ @DKNguyen, That would be too limiting. I wish, which might be too ambition but who cares, for machines that can fight in just about the vast majority of planets. Sometimes you are fighting a race the lives in a water world and other they have rocky high gravity world. Constantly changing the machines of war I think creates problems. $\endgroup$
    – Seallussus
    Commented Oct 2, 2020 at 21:15
  • $\begingroup$ Obliterate from orbit. Maybe the next society to arise from the ruins in a few centuries will be more amenable. If not, rinse and repeat. $\endgroup$
    – user535733
    Commented Oct 2, 2020 at 21:45
  • 1
    $\begingroup$ @Seallussus You want your spider platform to function any environment? Why bother with legs at all when you have anti-grav? $\endgroup$
    – DKNguyen
    Commented Oct 2, 2020 at 22:55
  • $\begingroup$ @DKNguyen, You are of coures correct in theory. But just like real world military. Economy. Making anti gravity teach requires more resources. Which becomes a problem especially if you re making the standard most numerous machines with it. Just like that scene in the Dark Knight when Fox told Bruce that the government did not think a foot soldier is worth that much when referring to the high cost of the armor. $\endgroup$
    – Seallussus
    Commented Oct 2, 2020 at 23:03

12 Answers 12


The Floating Interdiction Orb

You have anti-gravity. So flight profiles are irrelevant; you don't need flight control surfaces, you don't need weapon mount points that keep the vehicle balanced. So, a sphere. No edges, no specific weak points. Variable-opacity surface ports allow for laser weapons. Since you haven't specified an energy limit, I'm assuming they have a year-endurance battery, so anti-air missiles are pointless; the orbs can travel to wherever they need to kill something.

As a last-ditch mechanism, any opponent which proves resistant to the Orb's laser weaponry receives the Orb itself travelling at velocity before it detonates its power source.

Orbs come in a variety of sizes, but the most-commonly-deployed model is the size of a soccer ball, and can link up via electromagnetic contact points with other Orbs for search-and-rescue lift operations.


I forgot to mention the Orb's abilities in crowd control and occupation. Variable opacity also allows the Orb to display its smiling face when dealing with the public, and it is more than capable of communicating in any number of languages.

Advanced body-language interpretation algorithms and millimetre-wave scanners allow the Orb to both detect concealed weapons and anticipate hostile actions, and a lack of a defined "front" or "back" means that even in a guerilla warfare situation, the Orb cannot be snuck up upon. In the event that IEDs successfully eliminate an Orb, it's still cheaper than deploying a human.


If you control the space above an occupied planet (or around an orbital habitat) you have basically already won the battle.

This is because your fleet has the ability bombard the planet or habitat into submission. Both of which for the purposes of space combat can be regarded as 'fixed' positions. So I imagine given a 'sane' enemy you shouldn't really need infantry such. If however an enemy won't surrender for some reason you can drop hordes of drones of various sizes onto the surface of either. Then the limit is imagination.

Everything from swarms of micro sized drones designed to take out enemy electronics, jam their sensors or contaminate the local environment to human sized fighters and large fire support 'tanks'. Humans will still have to be in the decision loop of course.

As for different environments? Given the tech level your describing it might not be as difficult as you think. There may well be be a division between zero g/space based drone designs, planetary surface drones and aquatic systems. But high tech drones designed to fight on a planets surface should be able to handle a huge range of temperature and surface conditions - it would be included in the design parameters from the start. So within limitations imposed by say size or power they should be able to cope with hills or swamps, ice or desert ect.

But even with advanced AI networks it might be necessary for human 'command teams' to drop with the attack in order to supervise local operations i.e there is likely to be too much information flowing in for one centralized command post to deal with - no matter how advanced it is! As your tech level goes up so does the sheer amount of raw data and intel you have to manage. And that's one thing that's never going to change in war! So I could imagine say drone companies' being lead by a human command team reporting into a 'battalion' command team then upwards to a 'brigade' command team etc.

The only way I see humans fighting on the front is if both sides have the technical capability to completely neutralize each others short distance com systems so you literally can't network the battlefield. But that's the same kind of ongoing tech battle as you see with arms vs armor i.e. incremental advances on all sides with one advance in protection being overcome by the next advance in armor penetration. So again I don't think that likely.

  • 9
    $\begingroup$ Like how the USA controlled the air above Vietnam and was quickly able to use that to turn the war in its favour? If your military controls the high ground but there are a voting public back home with morals, you're not going to be able to blow up the planet and call it a day. A Vietnam style guerilla warfare will be lost from orbit too. $\endgroup$
    – Ash
    Commented Oct 3, 2020 at 16:45
  • 1
    $\begingroup$ A false analogy. Firstly the question assumes that for whatever reason in the far distant future a war is being fought. Whether there is popular support 'at home' or not is not one of the starting conditions. Secondly your completely ignoring the implied advances in technology. In terms of air to ground combat vast majority of the weapons used in Vietnam were 'dumb' bombs, first generation smart weapons were just starting to make an appearance on the battlefield, no GPS, no real time satellite surveillance and no drones in combat etc. And unlike Vietnam you have no way to hit back $\endgroup$
    – Mon
    Commented Oct 4, 2020 at 0:09
  • 3
    $\begingroup$ It's not just the presence of a moral home population. If you're fighting a war for a planet, you presumably want something on that planet, right? What's the point of conquering a smoking wasteland? $\endgroup$ Commented Oct 4, 2020 at 4:59
  • $\begingroup$ Personally? The only reason I can think of is that your society has been involved in a war with another extremely aggressive opponent & has either suffered great hardships and/or great losses as a result. If and only if they will not surrender. If your side is not willing to commit genocide and but wants to prevent such a war ever again then the only option is go down and take their infrastructure from them. so they literally can't make war anymore. As I noted in my header I actually think ground warfare in such a scenario is highly unlikely $\endgroup$
    – Mon
    Commented Oct 4, 2020 at 6:48

Medium Modular Hover Tank

Superheavy vehicles and battlefields are a thing of the past. Why you say? Well they've all been made redundant by the super DUPER heavy starship we arrived here on. Most battles occur in space between starships, each of which has no trouble taking out entire cities.

Most battles are skirmishes inside cities where you want to avoid collateral damage. So we need something slightly more powerful but less maneuverable than infantry.

As much as it hurts to remove the infantry from the equation I think it only makes sense to completely relay on machines to fight for us once we reach a point that allows it. Right?

Since there are no standing battles anymore, infantry are THE main type of troops. It's easy to send out your army of KILLBOT 3000™ to murderkill everyone in the city. But you can just as easily do that from orbit, so it makes more sense to send in human troops who can avoid massacring thousands of civilians among the enemy troops.

Their main backup is a hovering weapons platform the size of a small car. Those guys are entirely modular. Their weaponry is decided when they are sent down from the battleship. They can carry other equipment too like wide-area shields to cover a platoon of advancing infantry. They hover to get over rubble and uneven surfaces. This means they're also good for forests, glaciers, et cetera.

They don't need anything so large as anti-air missiles since anti-air defense is provided by the starship.

There is also a smaller version that can go inside buildings.


If you have orbital weapons around the planet, you may have won in theory, but all you can get is a shiny glass parking lot, not a planet full of workers producing sophisticated gadgets.

If you want the latter, you need to drop something on the planet that fights the enemy's military structures but leaves the civilian parts of society alone. That is way too complex to navigate with the simple rules you can give to a computer in an automated weapon system, while the rule "target any automated weapon system that isn't sending the right code" is easy. Throw in heavy civilian drone traffic on the target planet that you want to disrupt as little as possible (because that economy is what you're after), and defense against automated weapon systems is at a massive advantage. Any technology that can make friend-or-foe decisions in an urban setting is essentially sentient and has better things to do than fight for someone who deems them expendable.

So without human troops, all you can get is a stalemate or a Pyrrhic victory.

We see this in current warfare as well, and it's not likely to change with technological progress. Unless you put "boots on the ground", you can't win, even if you're technologically dominant.

  • 1
    $\begingroup$ I appreciate it. But. "that economy is what you're after" That is not always true in every war. Sometimes you want X others Y. Also the AMI is not true AI but is has all the practical aspects of human soldier and small officers. Boots on the ground I imagine is like fielding Warhammer 40K tanks, flyers...etc and throwing our infantry at them. A single tank from that world can obliterate a full brigade in a single salvo and is impervious to even our missiles and anti tank weapons. Not to mention other cheap forms of anti infantry weapons such as drones. Other FTL empires exist. $\endgroup$
    – Seallussus
    Commented Oct 4, 2020 at 3:36

Emphasise your peace with big friendly vessels. Ensure it with big data. Fight your wars with hidden nanotech.

You need 3 basic vehicles:

  • A 'peacekeepers' ship. Has:
    • Powerful Shields.
    • Ftl.
    • Self defence style weapons (close in railgun / intercepting laser beam weapons, etc).
    • No visible long range weaponry. (Some hidden long range missiles can exist - but the vessels appearance must appear friendly)
    • An ambassador, authorised to accept new planets into the empire, as well as make trade, peace treaties, etc on behalf of the empire.
    • A "press secretary" or "civilian liaison" or "propaganda sharer". Someone with no power but talks to the people and puts a friendly face on things as their job. Always in the media.
    • A military commander and a few underlings.
    • Support crew. Pilots, engineers, ships doctor, whatever is needed.
    • Carries hundreds of smaller "UAV" vehicles.
    • Scattered throughout the known galaxy. 1-2 ships per conquered solar system to "keep the peace". 3-4 ships per solar system on the empire's edges.
  • "UAV" vehicles.
    • Small sphere. Size of a basketball. Anti-gravity drive. - Can have multiple variations if spheres are boring.
    • Has an AI core in it for tactical decision making.
    • Can get strategic direction from an underling on the peacekeeper ship
    • Small shield to make it difficult to attack.
    • No direct visible weapon.
    • Only thing visible on the surface is friendly messages: "Keeping you safe" sorta stuff.
    • Carries millions of nanobots, controlled by a link to the AI core.
  • Nanobots do the bulk of your work.
    • Tiny small robot. ~1 nanometre size. Smaller than a grain of dust.

    • No local AI. controlled by the nearby UAV.

    • The UAV directs nanobots over everywhere within communication range - maybe 3-4 UAVs per continent, and a few UAVs in orbit.

    • Can get in anywhere and build up big data. They map the entire galaxy. They listen to every conversation. They record every facial expression, every printed word, etc. They get into computers and copy all the data (can do from RAM to bypass encrypted storage) They get into brains and directly read thoughts. Data is sent to the UAV, to the ship, and back to some central processing facility.

    • Can sabotage enemy military equipment, decay critical bearings, crack fuel pipes, short circuit critical computer chips, etc.

    • Can also hook into enemy technology. Can drive enemy tanks off cliffs, can crash enemy UAVs. Can send fake orders to troops and then replace the authentication process. Can turn enemy superweapons on their own commanders.

    • Deals with enemy soldiers, military commanders, politicians wanting to not be in your empire, or journalists digging too deep by literally getting in their heads and:

      • Releasing positive hormones when the empire in mentioned to associate good things with cooperating with the empire. Releases negative hormones when fighting the empire is contemplated.
      • Same hormone play is used to socially isolate anyone opposing the empire from the rest of society. Those who oppose the empire are unable to make friendships or advance politically.
      • Deleting / blocking negative memories of the empire.
      • Blocking the skills you need to fight the empire if you want to for some reason.
      • Or if all else fails - inducing heart attacks, strokes, cancer, seizures, etc.
      • They can also block all memory of the nanobots, if you notice them in something and investigate you'll conveniently forget they are there.

Everyone in the empire has a wonderful life, and as the empire tries to expand, most people get a good feeling about joining and peacefully vote to do so. Some people oppose it but their opinion doesn't carry much weight, (and a few have died of natural causes).

Your empire occasionally comes across a war hungry people, but their weapons are always poorly designed and fail in the heat of battle.


The first thing we need to know when designing is how it'll be used in the first place, what its goals are and how to possibly achieve it.

1: FTL

FTL determines a lot of the tactics. If you can FTL directly onto the planet surface with no interdiction you can land virtually anything no matter how large. If you can only enter the system after months or years of travel and then have to carry everything to the planet and land it "normally" you are much more limited in what you carry and how much. I'll assume an "exit close to the planet, has to move into orbit and use magic no-fuel landing boats" that seems to be the norm for many Sci-Fi.

2: Orbital Bombardment.

  • politics.

orbital bombardment is often touted as the final word. You are in space, they are in a gravity well of a planet. Just dropping rocks and asteroids is enough for nuclear level impacts. But orbital bombardment is a political nightmare akin to the MAD strategy. You use it for terror (limited orbital bombardment) and extermination of entire species (full scale bombardment). Anyone else in your Galaxy will instantly have to oppose you or risk getting exterminated as well. Imagine if a nuclear power, France or India for example, started nuking nearby countries in order to capture them. Would the rest of the world just sit by and say "well no problems there"?

  • economics and cost/effectiveness.

Using Orbital Bombardment is cheap for what it can destroy, assuming your FTL allows you to carry the mass and weaponry to the planet. However if you want to capture the planet you've just destroyed its population, who are still smarter than computers and have intellectual value for you. You've destroyed its infrastructure that you need to get around the planet efficiently or get resources into space (space elevators and ultra-long transport railguns). You've destroyed its refinement and production facilities and lastly you've reduced much of the usable material inside all of these structures hard to recover for your purposes. Repairing any one of these will be magnitudes more costly than an armada of invasion drones.

Orbital bombardment simply isn't that useful outside of a few niche cases. And we haven't even covered the possibilities of using that energy shielding to catch orbital bombardment projectiles before impact.

3: This brings us to your invasion force:

Their purpose is control of an area so they can stop traffic or take materials, goods and war/supply materials. They have to be able to reconfigure existing automated structures to work into their favor and they have to be able to take control of the political and administrative functions of the planet until living beings/specialized machine intelligence arrives to use it.

That means the most valuable unit you can build equates to Mechanized Infantry. An IFV-like vehicle that carries smaller drones. These smaller drones have to be able to navigate inside of cities, facilities and buildings while the vehicle can navigate any planet surface in order to get it there. Using hover technology is probably your best omni-purpose bet. Although in high-gravity environments you might want to use legged vehicles with the hover technology as assists for the vehicle to move around. Yes, legged vehicles. Tracked vehicles are much more constrained to roads and infrastructure than most people realize, and more vulnerable to being disabled. An 8-legged vehicle functioning as something akin to an 8-wheeler would be far superior for generalistic any-environment combatant compared to tracks, especially if it can activate hover abilities when necessary or when the environment allows to quickly move across terrain. It also makes landing easier if the IFV drops its cargo and makes idling more energy efficient than having the hover engine on constantly.

The drones would likely be either hover-tech or legged as well since they'll be the size and cost of infantry. If you want to destroy something the IFV will bring the firepower, and if you need more firepower a very limited orbital bombardment, a modified IFV turned to artillery or an aircraft equivalent will likely do the job perfectly.


FTL-delivered nuclear pumped-laser missiles. The idea would that the missile travels via FTL drive into close proximity of its targets, sends a sensor pulse back to guide the next missile then blows up, frying its targets with X-Ray lasers. This should be unconcerned with its environment as it will only spend milliseconds in real space and does not need any sublight propulsion. It is also, given the tech level, a simple to produce weapon system. In peace time they can be stockpiled in large quantities to be released in a relentless wave in event of war, frying everything in its path that is deemed a worthy target. Also, don't let the enemies get too close, these things will make a mess of the local environment by a constant stream of nuclear blasts.



  • $\begingroup$ The OP wasn't asking for space combat weapons - they were looking for something replacing infantry and armour divisions. Generally you send those in if you intend to keep the territory they're reclaiming from the enemy. $\endgroup$
    – jdunlop
    Commented Oct 2, 2020 at 21:13
  • $\begingroup$ I was thinking offensivly, flatten and then send in the terraformers. $\endgroup$
    – lijat
    Commented Oct 2, 2020 at 21:40
  • 1
    $\begingroup$ You don't need nukes (or Weber-esque bomb-pumped lasers, either) in that situation, then. Ordinary megaton-range nukes will do the job more effectively. And if you have FTL, why bother capturing territory you need to then terraform when you can just choose unoccupied territory and terraform that for cheaper? $\endgroup$
    – jdunlop
    Commented Oct 2, 2020 at 21:50

Well, "what will our fighting machines be like" largely depends on whether your projected audience are left-wing types who believe that all conflict can be avoided by a hug and negotiation, or right-wing types who embrace regimentation and "police actions" as a fact of life.

My own feeling is that there will always be scope for infantry to deliver a "short sharp shock" which avoids the sort of collateral damage inflicted by even the best large-scale weapons. Furthermore, there will always be scope for an assassin or a covert hit squad as long as they can blend in with their antagonists.

Now there is obviously the counterargument that infantry's job can be done with precision guided weapons, but in the absence of high-grade AI in the guidance system (with all of the universal rights arguments that implies) that sort of thing is only effective if the controller is within the few thousand miles dictated by the speed of light... and that similarly argues against remotely delivered assassination of key leaders.

So just as the best-ordered factory or building site occasionally needs a strong man skilled in the use of a big hammer, future military action will undoubtedly need infantry. But possibly not many infantry, and possibly with a level of intellectual competence which puts the average Imperial Space Navy officer to shame.


If you need fighting machines at all, it will only be to assist your infantry

When you have a warship in orbit, it doesn't matter how many super fortresses, destructo-titans and battleoids the defenders have, as you can precisely bombard them with high powered lasers, O2S missiles and 30 foot tungsten rods. The only time you don't want to do that is when obliteration from orbit will not help the situation.

This could be when you want to retrieve a package, sieze a broadcast station or remove a problematic governor without levelling the palace. Your warship will be keeping watch over head to eliminate any obvious reinforcements, so all your infantry will have to deal with is other infantry and similar sized combat vehicles.

Your infantry might be sophisticated machine soldiers rather than flesh-and-blood, but their role is the same. Have boots on the ground, be a visual indicator of who is in control, and to deliver the precise amount of violence necessary to get the job done.

So, your fighting machines will all be human sized at most, and be designed to enable your infatry to do their job better. Most likely they would be small, armed hover drones that can fit through gaps and thus approach from unexpected angles, likely modular so they can be loaded up with anti-personnel, anti-vehicle, and peacekeeper weaponry as needed.


Playing Devils Advocate for Infantry

Something you said, that I very much agree with, is that while it may not look the same, our technology now is already at a point where it embodies it's role perfectly.

In the far-flung future, we may very well have giant robots and mechs and tanks and warmachines, but in my opinion this doesn't negate the role of the humble infantry-man.

Consider the following: In the modern day, with modern weapons, an infantry-man can take out a tank on his own. By placing himself in an advantageous position with ample cover, he can wait for an enemy tank, which most likely hasn't noticed him (and at some distance), and fire an anti-tank rocket or other anti-armor device.

Likewise, most militaries since the invention of the tank have made use of this on a larger scale, with Anti-Tank squads

Infantry are cheaper, more autonomous, better able to flank, more numerous, more adaptable, able to fit into smaller spaces and able to find better cover, and certainly much better at using camouflage.

Even taking into account infra-red or invisibility tech, surely it's much cheaper to outfit a soldier with invisibility than it is to outfit a tank. To combat infra-red or other methods, some sort of lining of the Armour could surely be made use of, or some sort of scrambling or heat-sink device.

This applies just as much in the future as it does to now. If a few men with a good position can take out several tanks and then seemingly disappear, why wouldn't you make use of them?

Having a forge-world doesn't negate this...if you can afford better stuff, it just means you can afford MORE and BETTER infantry.

Autonomous drones and robots and the like also don't quite fill the niche as well, considering a few points:

  1. Single point of failure (being a mainframe, drone-network or network for the AI) even if each robot has it's own AI, surely they are less adaptable and less autonomous than soldiers with a command structure on the ground

  2. If AI is better/faster/stronger than humans...humans with cybernetic AI-cores, strength augmentations and the like are going to be even better.

  3. Logistics: robots and tanks are all heavier than infantry. Your shuttle/landing craft might thank you for making use of infantry.

That's not to say that INFANTRY are the best at EVERYTHING

But having your tanks and robots supported by infantry will provide a force to be reckoned with...combined arms is key.

  • $\begingroup$ Your points are incorporated into Warhammer 40K. I think they are correct to an extent but here is the problem. Tank, example, armor and tech can reach a point where it is simply impossible for man held weapons to oppose it. Drones, detection technology, and overall data can reach a point where you need expensive anti detection tech. But also the future battlefield might be so filled bullets, laser, CBRN weapons...etc that it is simply cheaper to field a competently automated unit that armor a human. AMI in my world is like I said: infantry level ability. So. Would they still make sense? $\endgroup$
    – Seallussus
    Commented Oct 4, 2020 at 17:03

I think that the first question should be "Would FTL capable humanity need a reason for fighting machines?".

FTL capable civilization would be able to destroy whole solar systems in one go and it would be a post-scarcity society in a huge galaxy. The only reason for fighting would be ideological and with those premises above - you would simply destroy whole star system where your enemy is.

With that in mind, my answer would be "None".

  • $\begingroup$ Clausewitz is adamant that war is a tool to further political goals. So even if we accept your "ideological" point there we still require machines to fight on the ground. I also mentioned the scaling of our military as the US, an example, still uses infantry and does not think: Air superiority ftw! The galactic scale it is the same. War is incredibly dynamic to the point that it is very much reasonable to need to fight inside planets. Not to mention other FTL power opposing your own fleets. Or the need to remove an opposing government without shattering the planet...etc. $\endgroup$
    – Seallussus
    Commented Oct 4, 2020 at 16:21

Start with some better SF. Take Iain M Banks' Culture novels.

Chemistry based materials are not military grade. Warfare is field based at some scale.

Tiny, tough, field-reinforced knife missiles with a reasonable intelligence make biological troops pretty obsolete.

New kinds of manipulation of reality -- gravity control, FTL, force fields -- lead to fundamentally different warfare. What you are describing is like a roman solider, when described the industrial technology of today, thinking "tougher shields, tougher armor, better fed soldiers, sharper swords, more troops".

You can take a roman soldier, give them ridiculously better swords, shields, food, and you'll get a better combatant. In fact, that is roughly what our riot police are using.

But that isn't a military force.

At the top of our military pyramid is CBN warfare -- chemical, biological and nuclear.

Outside of total war, those aren't used. And because total war would wipe out humanity, total war has become rarer; the only people who use CBN warfare are people who feel they have nothing left to lose.

Under that we have capitol ships, like US nuclear aircraft carriers and submarines. These use a derivative of our top-tier technology. They are used to project force without triggering total war, and to suppress insurrection against the global order. Using conventional explosives (missles etc) they trump the next tier.

Under that we have network based combined arms. A mixture of heavy and light tanks and Kevlar-wearing heavy infantry connected over a network, calling on heavy air support on hardened targets.

Under that we have lighter infantry, be it less financed governments, irregulars or police-style troops, possibly using light civilian-tier mechanization. Asymmetric guerilla warriors, using IEDs and the like, go here.

Under that we have policing troops, who use less-lethal weaponry to deal with civil unrest or crime.

Each tier trumps the one under it.

You could reasonably have most of these tiers in a higher energy scale civilization. Each would be more optimized and improved over the modern stuff. Higher tier gear would be available to lower tier use-of-force (like how riot cops have better gear than roman legionaries did), plus wiz-bang high-tech stuff (tazers, guns, tear gas for police).

Even if the wiz-bang-upgraded police force could mop the floor with a roman legion, it doesn't mean the police force is a military solution.

So I'd start with the near future of warfare. Something we can plausibly do with near-future tech.

A single soldier having dozens of combat drones extending her awareness and kill capability to line of sight and beyond. Capable of taking down things on the scale of modern battle tanks and detecting enemy forces. The infantry at the core exists because enemy communication jamming is possible, and the LOS to the infantry CNC is a fallback.

That is a force designed to trump irregulars. Police level will have a lower tier version of this.

To trump that, field based warfare that shuts down that kind of technology and communication. Gravy-guns, effectors, etc. Capable of flattening a city block from the other side of the solar system.

To trump that, hyperspace capital ship interdictors. The projection into normal space is small, with the bulk of the ship embedded in hyperspace. It prevents others from moving FTL or doing the same, and control over the cubic parsec is fought in hyperspace.

Above that, total conversion weapons that convert entire stars into fuel for FTL weaponry. This is a total war weapon.

Stellar converter tier. Total war. Destroys galactic arms.

Hyperspace interdictors. Capital ships. Controls radius in many light years.

Battleplates. Gravy guns, field effectors. Controls solar systems.

Drone augmented cybernetic heavy infantry. Suppresses irregulars.

Robotic riot police. Controls civil unrest.

Beat cop. Polices crime.

  • 2
    $\begingroup$ "Each tier trumps the one under it." If that is the case, how come irregular fighters have pushed the British Empire, the American Hegemony, and the Soviet Union out of the vast majority of their territory over the last 75 years? (Battleplates and gravy guns... and it was the one tough bastard came out on top of that one :-) $\endgroup$ Commented Oct 4, 2020 at 17:07
  • $\begingroup$ "Battle-hardened knife missiles"? Who needs a hunter-seeker when you can put a laser on it? $\endgroup$ Commented Oct 10, 2020 at 12:20

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .