Brainstorming a sci-fi setting, and justifying interstellar war

[TaranTheWanderer]

Hence why I think I'd prefer going with my own setting. I just don't buy it being possible to suppress all the scientific knowledge before people figure out what you're up to and stop you.

I dunno. Maybe if, like, every planet got bioweaponed or nuked, and civilization entirely collapsed everywhere, and people had to rebuild everything from scratch, only to occasionally come across a few bits of ancient tech in bunkers.

I suppose if you have a book that says, "Here's how fusion works," it'd take a long while to build the first reactor. Case in point: reality.

Of course they will eventually learn to use the technology and will learn how to fix it. It's simple: you just pray and perform a religious ritual in a specific way that was memorized by rote, with very specific ritual artifacts. Voila, you've successfully appeased the Machine Spirits and got it your magi-tech back up and running.

 

[Tonguez]

Why not just planets in a single star system? (maybe even our local Solar System) - I once played in a sci-fi in which I was the Verenigde Joviaanse Republiek (United Jovian Republic), ruling Callisto and the other Jovian Moons and harvesting gasses from jupiter. Anyway all the moons of Jupiter and Saturn were inhabited (the outer moons as mining outposts), as were most of the planets including Ceres, Pluto and Sedna, each of them independent.

One of the techs I concentrated on was EM Shielding and EM Propulsion systems, that allowed me to manipulate and use Jupiters Magnetosphere for both defense and offense. The story being that EM tech had become essential for the colonization and survival humans on the Jovian Moons.
Anyway through various machinations including a tachyon pulse that cut off communications all the planets got into a state of high alert and system wide war.
It was a blast, ships using the magnetosphere of Jupiter to slingshot to the outer planets, I started a cult that worshipped the Great Red Spot of Father Jupiter

 

[payn]

You'll likely just end up with your own BT that folks will say is nonsensical. Ultimately just use what you need to make sense for you.

 

[Paul Farquhar]

Have you seen this thread? https://www.enworld.org/threads/tra...r-war-begins-in-two-days.703327/#post-9299744

 

[UngainlyTitan]

I actually am going down this rabbit hole specifically because I came up with what I think is a rational technological justification for mechs.

The idea is basically instead of just armored walking tanks (which is what Battletech canon says), mechs have really strong forcefields that shed a lot of EM radiation that messes with remote communication and can fry any fragile transistors.

So like, a lot of the stuff we use today - cruise missiles, drones, and the potential of stuff like self-piloting computerized vehicles - don't work because the EM release of the shields will fry anything other than a pretty simple system with a lot of hardening.

The way shields would work is that they 'harden' against impacts from the outside, but normally they're uni-directionally permeable so you can launch your own missiles and fire your own ballistics. When something impacts, the shield pumps some energy into the spot hit to nullify the whole impact. However, if you get hit in rapid succession in different locations, the shield struggles to recalibrate to block them all.

Basically, multiple scattered hits bring the shield down faster than singular big hits. A big cruise missile like a 1 ton Tomahawk is less useful than peppering a mech with a half-dozen 10 kg rocket propelled grenades. This brings the range of engagement much closer than what happens with modern smart missiles.

You could also just totally obliterate a mech with a cruise missile (or a high-explosive tank shell) if you could hit, but you'd need to time it right to hit after you drop the shield but before the shield can get back up. The three main weapon types are thus:

Lasers - go through shields, but do fairly minimal damage.
Small Missiles - best at dropping shields.
High-explosives - best for killing shots.

Ok, I had a quick look to refresh my memory and mechs are huge, house size or larger in height. They can be seen from 10's of kilometres away.
This makes them vulnerable to direct artillery fire from cover to the area that they are moving in.
They weight in the same range as tanks but that load is all on the feet. I doubt that they could manoeuvre on most surfaces. The soil would not take the weight.
They are fundamentally unstable, so are humans but it is worse for a mech and they are very vulnerable to trip effects and land mines targeting the feet and ankles. This also makes for more complex maintenance and logistics.
These are my principle objections to mechs. The big one is size and it has gotten worse over time. We have drones that are hard to spot and could spot mechs moving from tens of kilometres away. Once they can establish range and movement vector, just call-in artillery from out of line of sight to the mechs and bomb the area until there are no more mechs.
I will add that if they are generating that much em from their shield then use that em as guidance or method of location.

Also, the shield has to be a complete shell or it quickly loses its stability and collapses. If you put a shield around, like, a tank, the tank treads would be spinning against the inside of the shield, but would barely transfer any force to the ground beneath. If you put a shield around a plane, the airflow would be blocked so you couldn't get lift.

But due to the way biped locomotion works, lifting the feet and then striding, you can put shields around a mech and still be able to move.

Are you saying that the mechs are effectively in a hamster ball of shielding and are stepping on that to move?
If the mech is moving by putting weight on the forward edge of the shields could not a wheeled vehicle not do something similar?
How does the mech shoot through its own shields?
Can the shields be shaped to work as a ground effect vehicle?


All that said, had wave it away and play with mechs.

 

[payn]

Ok, I had a quick look to refresh my memory and mechs are huge, house size or larger in height. They can be seen from 10's of kilometres away.
This makes them vulnerable to direct artillery fire from cover to the area that they are moving in.
They weight in the same range as tanks but that load is all on the feet. I doubt that they could manoeuvre on most surfaces. The soil would not take the weight.
They are fundamentally unstable, so are humans but it is worse for a mech and they are very vulnerable to trip effects and land mines targeting the feet and ankles. This also makes for more complex maintenance and logistics.
These are my principle objections to mechs. The big one is size and it has gotten worse over time. We have drones that are hard to spot and could spot mechs moving from tens of kilometres away. Once they can establish range and movement vector, just call-in artillery from out of line of sight to the mechs and bomb the area until there are no more mechs.
I will add that if they are generating that much em from their shield then use that em as guidance or method of location.

Are you saying that the mechs are effectively in a hamster ball of shielding and are stepping on that to move?
If the mech is moving by putting weight on the forward edge of the shields could not a wheeled vehicle not do something similar?
How does the mech shoot through its own shields?
Can the shields be shaped to work as a ground effect vehicle?


All that said, had wave it away and play with mechs.

You are just scratching the surface. Most mechs have no head lamps or night vision so they take massive penalties to mechanics in darkness... Drones were not really visualized back in 80's when BT was created but there are even more basic items such as mentioned not accounted for as well.

 

[UngainlyTitan]

You are just scratching the surface. Most mechs have no head lamps or night vision so they take massive penalties to mechanics in darkness... Drones were not really visualized back in 80's when BT was created but there are even more basic items such as mentioned not accounted for as well.

I have never played Battletech nor looked at the rules in forty years. I did play the board wargame cannot remember the name of it. But this is getting into the weeds of the actual rule system. If they guy wants more "realism" in a mech game then some of the foundational conceptual issues should be looked at.
War is a game of rock paper scissors. Most of the stuff is there to counter other stuff. Some things are inescapable. If one side has total air superiority then the other side is in deep trouble as the side with air superiority can hammer the other sides logistics and C3 infrastructure until they cannot sustain organised resistance.
Of course that does not mean victory. An insurgency can be successful.
Getting back to mechs, define their role, are they breakthrough units or fire support platforms, or whatever and do not forget the Iron Triangle of armoured units: mobility, protection, firepower; pick two.

 

[payn]

Getting back to mechs, define their role, are they breakthrough units or fire support platforms, or whatever and do not forget the Iron Triangle of armoured units: mobility, protection, firepower; pick two.

Thats the age old debate. Should a mech be an all purpose platform, or a specialized unit? I will give BT this, however, mech designs do follow the iron triangle (typically some dark ages stuff is just cheesy).

 

[MGibster]

Unless something like unobtanium exists it’s hard to imagine a resource based war—there’s nothing I can think of that would gain more than the cost of the journey. Minerals? Water? Oxygen? Gold? It’s all abundant in the universe.

I think this pretty hits the nail on the head. For most science fiction settings, you've got to suspend your disbelief when it comes to some base assumptions of the setting or you're never going to enjoy it.

 

[Deset Gled]

But why tolerate letting mechs even land on your planet? Why not invest in orbital defenses to shoot down dropships with torpedoes and rail guns and the like?

I'm struggling to think of situations where interstellar war with mechs on the ground make sense. Maybe I could just skip the whole 'interstellar' part, and make it instead be conventional warfare between nations on the same planet. And like, interstellar combat would be less 'invasion' and more 'backup for whichever local nation we are allies with.' Y'know, more akin to the US helping the Kuwaitis in Operation Desert Storm, and less "Crossing the British Channel on D-Day."
...
Maybe few planets are pleasant enough to support large populations, so instead you have like one city of 100,000 people, and some farmland and mines around it, all designed to support a spaceport that launches resources so they can build ships in orbit and sell food to passing jumpships? If we imagine that the setting has some super-efficient fuel so getting out of a gravity well isn't that big of an expense, it would be safer to grow food on planets with atmospheres instead of doing it in domes on moons or asteroids with lower gravity.

Unless something like unobtanium exists it’s hard to imagine a resource based war—there’s nothing I can think of that would gain more than the cost of the journey. Minerals? Water? Oxygen? Gold? It’s all abundant in the universe.

I think you could do a pretty good handwave that that "limited resource" in this universe is habitable planets. It gives you a limited resource that people would be motivated to both fight for and maintain. And it's based in reality (lot of planets really aren't suitable for humans).

It also provides a somewhat plausible explanation for the planetside battles. There is a real problem of "stuff" in orbit being quite difficult to deal with. Too much junk in space close to a planet can make travel or maintaining satellites quite problematic. For that reason, the clans could all have agreed to avoid space battle at all costs, essentially treating a space battle the same as nuking a planet and leaving it full of fallout.

You've still got to deal with why people fight with mechs instead of drones, artillery, whatever. But that could give you a pretty good start.