Megastructures?

[Maximum7]

I’m looking for an idea for a megastructure in space for my RPG setting. They’ve come up with Dyson spheres, Alderson Discs, Niven Rings, Globus Cassus, Shellworlds etc. I’m looking for an idea for a megastructure that is unique. I can’t think of one. Maybe they’ve all been speculated already. Does anybody have any ideas?

[ericthered]

Digging through Issac Arthur's Youtube Channel is probably a good idea. Specifically the megastructures playlist

There's an idea in there for stringing together rotating habitats in long ladder like structures: they spin independently, but the non-spinning cases are connected.

Spinning artificial planet-sized disks are surprisingly doable, and distinct from Alderson disks.

Dyson Spheres have a lot of variation. There is the dyson shell, the dyson swarm, and the dyson bubble. They look and behave very differently.

[Pragmatic]

The second Uplift trilogy had Fractal Worlds (where some of the Retired class lives). Basically, Dyson spheres with fractal geometries.

[William]

"Unique" is really hard, given the number of people that have been speculating. But "new to your players" is probably doable! "Not often done in a fantasy setting" is also possible.

What do you want the megastructure to achieve? If it's just high-magic architecture that's huge, you're fairly unlimited in your choices.

The Counter-Orrery: To the circumference of this disc-shaped world, some unbelievably high-powered magical civilization has affixed an enormous ring of adamant and orichalcum, the creation of which alone would have required the plundering of multiple worlds of this size. The Counter-Orrery holds a cage which can be loaded with a city-sized patch of soil, ice, pitch and fuses, wood, or other material as needed. Driven by the fires of the Beneath and the Infinite Falls of the constantly-renewed world ocean drifting down into the void, this hoist can be raised above the world, putting the material into the desired position in the sky, where it modulates astrological influences on the fates of the people below.

[Anaraxes]

A topopolis hasn't been mentioned in the thread yet. You might have multiple distinct ones braided together in the same space, but not connected, perhaps for different environments or just for "redundancy" as an excuse to have separated cultures or peoples. Travel outside, between tubes, could be good for shortcuts compared to the usual inside paths for long distances, and so narratively function something like teleportation or ley-line / Nevernever / the "Ways", etc walking in fantasy stories.

[Fred Brackin]

40 years ago, when I was in college (and doesn't that phrase cut like a knife?) My first campaign for FGU's Space Opera had a reverse-Dyson sphere.

It was a sphere the size of Earth's orbit but the Precursors lived on the outside so when the machinery failed they didn't all fall into the center of it. Making big streetlights on the outside were a lot simpler.

It was also built around a larger than Sol-szed black hole rather than a star. It was probably used for multiple sorts of Precursor-like exotic technologies.

It had been mostly wrecked in the last Precursor war but enough of the defense system still worked that ships over 273 tons one at a time were shot at with what were very big guns by modern standards. Very difficult to move in and take over for any government.

[ak_aramis]

Originally Posted by Fred Brackin

40 years ago, when I was in college (and doesn't that phrase cut like a knife?) My first campaign for FGU's Space Opera had a reverse-Dyson sphere.

Space opera wasn't out 40 years ago; were you a playtester?. (It was published in 1980)

[Fred Brackin]

Originally Posted by ak_aramis

Space opera wasn't out 40 years ago; were you a playtester?. (It was published in 1980)

Ah, an error of a few months. It's not quite 40 years since I started rpg-ing. That was in late October or early November of '79. The Space Opera campaign was probably spring or summer of '80 with a brand new box set.