…on the technologically advanced civilization vs. WH40K Imperium of Man scenario occasionally played with.
What we might have here is a really dramatic example of why you don’t want single points of failure, regardless of how well defended you think your single points of failure are.
Combine Jon’s Law (any interesting space drive is a weapon of mass destruction) with the Imperium’s centralized governance (not exactly great centralized governance, but something has to provide centripetal force to the whole tangled mess – even if that’s mostly a corpsified and gross symbol these days) and even more centralized navigation system (Astronomican), throw in the way that canonical WH40K assumes that space defenses are porous and blind at medium-to-long range, and what you have a situation that just screams “relativistic kill vehicle“.
Basically, you whack Holy Terra with an RKV, then smirk as the thousands of successor splinter states, reft of their unifying symbol, are only prevented from slashing each other to suicide by their inability to reach each other in any sort of organized fashion. You may not have cured your human problem, but you’ve definitely reduced it to manageability.
The fact that the Tyranids have not yet done precisely that is testament to the fact that, despite their considerable animal cunning, they are not, in fact, sophont. If they were, the galaxy would be in truly stonkingly great levels of trouble. (And they’re already pretty deep in SKYSHOCK BLACK-level territory for every faction that’s taken more than a cursory look at it.)
That, or proof that GW’s writers have no sense of scale and/or no particularly strong grip on numbers. But that was rather a given, belike.
This particular scenario seems particularly disingenuous, considering that 40K is 1) fantasy, 2) an over the top amalgamation of 80’s action movies, comic books, and popular fantasy/scifi novels, and 3) a setting that runs on narrative conventions.
An RKV wouldn’t take out Holy Terra because it’s not thematically appropriate.
Eh, less disingenuous and more a reflection of the way that – short of picking a universe with essentially similar or at least compatible metaphysical underpinnings – ultimately all crossover fanfics have their outcomes determined by whose narrative-fu is stronger.
(Much like the Culture-WH40K crossover is likely to result in the Emprah being displaced into a GSV from 15 kilolights away, then given a new body, and a lecture on how he’s a very naughty boy – ’cause odds are it’s a Culture fan writing.)
Anyway, for myself, I’m just poking this scenario because the question was asked, way back when. A good, compatible crossover/fusion-fic for this ‘verse would be, oh, Destiny, Mass Effect, My Little Pony: Friendship is Magic, that sort of thing. ‘Bout all you can do crossing it with 40K is a ‘splody-parody fic about grimderp being punched repeatedly in the face by a space magic fist of doom, and that’s just cheap if amusing literary porn.
(And I’m sayin’ that as someone who’s been known to define his subgenre as “awesomeness porn”.)
So…how would the Tyranids be dealt with?
With difficulty. (Although it has been pointed out before that the really big Tyranid problems require them to get planetside, and their space engagement capacities are relatively weak.)
But when it comes down to it, they’re a heggie swarm, albeit a really big one, and as such you can deal with them like any other heggie swarm. Say, like these three notions:
Paging Plague, Inc.
A fundamental weakness of all heggie swarms is that they’re composed of large numbers of identical units, and even heterogeneous swarms (like the ‘nids) are large numbers of a relatively small number of types of identical units, which usually have large design/genetic commonalities anyway.
Can we say “virgin field epidemic in a monoculture”? If we can do science to it, I think we can.
Induced Falrann Collapse
Technically not, since “Falrann collapse” is local jargon for “logistic breakdown due to coordination failures in seed AI”. Nonetheless, hive minds gotta communicate and coordinate, and unless their communication is one of a very few rare and special types, that means it can be jammed.
Feral ‘nids are a much smaller problem than hive-obedient ‘nids, even if they don’t fall into infighting. If you can jam their comms in such a way as to induce insanity and infighting, even better.
Anything You Can Heg, We Can Heg Better
This is the ADHAÏC CALYPSE scenario: so, you’re fighting a massive self-evolving self-replicating heggie swarm that can use all the organics it comes across as raw material? Well, we’ve got some self-evolving self-replicating von Neumann machines that can use all the matter they come across as swarm raws – not just the air, oceans, and life, but the entire planet from crust to core, say, which conveniently lets you blow it up first – with just the minor advantage of not being inclined to attack us . Sic ’em, boys!
(This is a strategy that will also make one hell of a mess of the galaxy, so is not to be preferred, but given the choice between a wrecked galaxy where you’re all dead, and a wrecked galaxy where you’re not, the choice should not actually be all that hard.)
OTOH, I have been very tempted to generate 40K-compatible rules for the various Imperial Legion hardware you’ve described so far.
(Ok, it’s pretty clear that I’m a bit of a Melvin.)
The latest Quentyn Quinn, Space Ranger actually touches on a 40K/FiM crossover over with a hilarious reaction from Imperial forces
Heh, yes. I’m looking forward to seeing how that plays out.
(At one point, on my fic-blog, I did opine on the shape of my ideal 40K/FiM crossovers:
‘Namely, that they should be only a few pages long at most, and should always end with “And then Princess Celestia hit the invading fleet in the face with the sun, reducing it instantly to a whiff of plasma, and harmony reigned once again in the magical land of Equestria.”
For a couple of reasons, one of which is that there are certain realism issues involved in picking fights with Kardashev Type II civilizations that become even more relevant when picking fights with Kardashev Type II individuals, but mostly because watching the fascist hate-cult avatar of grimdarky grimdarkitude being vaporized without breaking a sweat by the Sugar Bowl warms the spiritual cockles of my heart.
Those fluffy, fluffy cockles.’)
One other that comes to mind is the Gem Empire from Steven Universe. Kardashev II, warp drives, fusions, something that looks very similar to a wormhole network. There might be an actual conflict there, but also a bunch of sophs who would fit right in with the Imperials.
Some of the loyalist primarchs had a plan in place to maintain a remnant “Imperium Secundus” using some kind of warp artifact to maintain an empire of a mere 500 systems.
Then their elected Imperator Regis decided to go and sacrifice himself at the battle of Terra.
“Good, bad… I’m the guy with the gun.”