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I'm sure there is an answer to this somewhere. Why can't imperial vessels just fire an exterminatus into the nid fleet and wipe them out with great ease? Surely the hive mind would be unable to adapt to the virus quickly enough to save itself?

Virus bombs are easy for battleships to intercept and shoot down. There is a reason that you need space superiority before you can do an exterminatus.

Understand that but I just have never heard of any attempt to use them.

Virus can easily be contained within multiple types of warheads.

Well you can't virus bomb a fleet, because they are in space. A vacuum means that bomb would kill one ship essentially. As to bombing Nids on the ground, this happens a lot. But, Imperials are often reluctant to as it will ruin the planet forever which is the same as losing it to Nids, plus it is hard to achieve orbital superiority vs Nids.

Dawn of war 2 spiler alert.





The Dawn of War 2 Computer Game's storyline feature using viruses against Tyranids. I do not know how canon the Dawn of War games are, but they do a good job of making the Warhammer universe come to life in a narative arch that fits well with computer game structures.

Of the course of several levels you try to gather the right DNA and bio samples to design a virus that will get the job done. Arrantly the tyranids can adapt to very general viruses. Or more spesificaly you need to adapt the virus to something that can destroy the tyranids, and not just a small section of the local fauna. To do that the SM strike deep into the heart of the tyranids to get hold of some of the biomatter. With this they can make a virus that crippels the synapse and a lot of the tyranid forces are scattered. Enough for the SM to take out the stratetic assets that remain.

The DW2 exspansion pack shows that while a lot of the tyranids die, there are still enough spores to make a slight recovery, although not a very whole harted one.

In the last exspansion pack they actualy bomb a plannet that the tyranids are on (or demons kill it, I do not remember.) That game is pretty good as it deals with the consiusness and essence of the hive tyrant you play. Aprarantly if it does the wrong way it takes a long time to reform then if it is digested in a gemepool. This is some quasi hindu religius ideas about returning to the source material. It really fits in the storyline.

With a Cyclone Torpedo the amount of energy it unleashes is enough to destroy a planet. Hive fleets are much bigger than planets. Hive ships are not, but you need to hit a ship or something to detonate it.

Now, assume it hits the biggest mofo hive ship there, and detonates, wiping out the ship from the face of existence. After that, where does that excess energy go? Out, exploding ad destroying everything for a couple hundred light years. With a planet the energy is absorbed and used up in destroy the planet by the huge mass but the Hive Ships will be more of a speedbump. Then it'll take out a large chunk of ships, but after that, who's next in line? You.

As for Virus Bombs, the same deal happens but now you have the virus floating in space eating through your ship's hulls and your personel, possibly for millennia, and possibly falling on the planet you are protecting.


In either case, it would be easy enough to send a small interceptor ship to intercept if it was fired from a safe distance and minimise damage to the fleet.

A "modern" virus floating in space would die out quickly, the cold, lack of pressure and air and all that ...
I can't speak for a 40k virus though ...
Also don't tyranids rely on more than one "main" ship? Each larger ship can potentially infest a planet, so you'd have to destroy a huge number of ships in a tyranid fleet to get rid of the danger

Plus there is always that nagging fear that using the Life Eater virus against the Hive Mind will allow the Hive Fleet will adapt to the Life Eater virus, or worse yet build a controlled version of it into its own arsenal...

Xyptc wrote:
Plus there is always that nagging fear that using the Life Eater virus against the Hive Mind will allow the Hive Fleet will adapt to the Life Eater virus, or worse yet build a controlled version of it into its own arsenal...

That's not really a valid concern though, if we accept that tyranids wouldn't be as interested in consuming virus-bombed biospheres.

To the OP's point, given what we know about bio-ships, some kind of anti-Tyranid virus weapon could be effective against them(and we have fluff precedence for using biological weapons against nids, as mentioned above).

 Vaerros wrote:

Xyptc wrote:
Plus there is always that nagging fear that using the Life Eater virus against the Hive Mind will allow the Hive Fleet will adapt to the Life Eater virus, or worse yet build a controlled version of it into its own arsenal...

That's not really a valid concern though, if we accept that tyranids wouldn't be as interested in consuming virus-bombed biospheres.

To the OP's point, given what we know about bio-ships, some kind of anti-Tyranid virus weapon could be effective against them(and we have fluff precedence for using biological weapons against nids, as mentioned above).

If that's the case why are the most effective weapons (for a bog-standard marine) Hellfire rounds which use a mutagenic acid? Surely they are worried about the Hive Mind developing something like that, or worsed, become immune to it?

Keep in mind that it's extremely difficult to develop an effective virus against Tyranids. It has been done with great difficulty in the past, and the Nids adapted to it quickly, making it . . . not an option any longer.

 Deadshot wrote:

 Vaerros wrote:

Xyptc wrote:
Plus there is always that nagging fear that using the Life Eater virus against the Hive Mind will allow the Hive Fleet will adapt to the Life Eater virus, or worse yet build a controlled version of it into its own arsenal...

That's not really a valid concern though, if we accept that tyranids wouldn't be as interested in consuming virus-bombed biospheres.

To the OP's point, given what we know about bio-ships, some kind of anti-Tyranid virus weapon could be effective against them(and we have fluff precedence for using biological weapons against nids, as mentioned above).

If that's the case why are the most effective weapons (for a bog-standard marine) Hellfire rounds which use a mutagenic acid? Surely they are worried about the Hive Mind developing something like that, or worsed, become immune to it?

Looks like you mis-quoted here.

his is me just shooting from the hip, but I think a tyranid hive fleet could still be interested in a planet that has been virus bombed, as providing the consumption of the deceased matter doesn't contaminate the hive with the virus, or if it does they adapt to it quickly, the dead matter is still biomass that can be consumed. The main issue with virus bombs isn't the virus, it's the huge amounts of gasses that are released from the deceased inhabitants, most highly flammable igniting and burning the planet atmosphere... And turning it into one big useless rock, in space.

the imperium does extermintus planets the nids are attacking sometimes in an attempt to eistablish a "fire break" the milage they get varies

The Imperium is actually much more cunning. They sacrifice defenders on the planet so that the tyranids expend as much biomass as possible. Then, once the defenders are defeated, and the tyranids exhausted, they unleash an extemrinatus.

Pretty messed up fate for the defenders but effective at stemming a hive fleet who can't recover the amount of biomass expended.

 Deadshot wrote:
With a Cyclone Torpedo the amount of energy it unleashes is enough to destroy a planet. Hive fleets are much bigger than planets. Hive ships are not, but you need to hit a ship or something to detonate it.

Now, assume it hits the biggest mofo hive ship there, and detonates, wiping out the ship from the face of existence. After that, where does that excess energy go? Out, exploding ad destroying everything for a couple hundred light years. With a planet the energy is absorbed and used up in destroy the planet by the huge mass but the Hive Ships will be more of a speedbump. Then it'll take out a large chunk of ships, but after that, who's next in line? You.

As for Virus Bombs, the same deal happens but now you have the virus floating in space eating through your ship's hulls and your personel, possibly for millennia, and possibly falling on the planet you are protecting.


In either case, it would be easy enough to send a small interceptor ship to intercept if it was fired from a safe distance and minimise damage to the fleet.

That's.... really not how it works, or how energy is transferred for that matter. From what we've seen on videos/fluff, the cyclonic torpedo is powerful enough to ignite the atmosphere and destabilize the planet, not explode it like a Death Star blast....even if it did, that does NOT actually translate to "a couple hundred light years" explosion. Hell, even supernovas of the most massive stars dont get bigger than 10 light years, and that's a truly horrendous amount of energy, billions of times more than what is required to explode a planet outright. What's more, the energy from an explosion transfers far better through matter than void.

Case in point, a nuclear missile would be vastly more damaging on a planet than in space, where the energy is dissipated in light and radiation, both of which space shielding can take.. you dont even get a proper explosion in space really, due to lack of oxygen, and definitely very little heat transfer.... a cyclone torpedo would more than likely only kill what it hits, and the debris and explosion from that ship would only threaten small escorts around it. Same with the virus bombs, though without the danger to other ships, as the virus would not cause an explosion in space, since there will be little oxygen to ignite. As for the danger of the virus hanging around inert in debries, it's miniscule. You'd get it if it was capable of surviving in vaccum, should you willingly pick up the debris... but otherwise, space is massive. It's incredibly unlikely you'd accidentally run into it.

Knockagh wrote:
I'm sure there is an answer to this somewhere. Why can't imperial vessels just fire an exterminatus into the nid fleet and wipe them out with great ease? Surely the hive mind would be unable to adapt to the virus quickly enough to save itself?

Most methods of Exterminatus require some other agency to be present to work, such as an atmosphere to ignite, biological matter to convert into a flammable substance, or the crust and core of a planet to detonate.

Throwing a Cyclonic Torpedo at a Hive Fleet might kill... one ship. There's millions to go.

 Psienesis wrote:

Knockagh wrote:
I'm sure there is an answer to this somewhere. Why can't imperial vessels just fire an exterminatus into the nid fleet and wipe them out with great ease? Surely the hive mind would be unable to adapt to the virus quickly enough to save itself?

Most methods of Exterminatus require some other agency to be present to work, such as an atmosphere to ignite, biological matter to convert into a flammable substance, or the crust and core of a planet to detonate.

Throwing a Cyclonic Torpedo at a Hive Fleet might kill... one ship. There's millions to go.

Fire a few more then! Surely it more effective than trying to blow chunks of meat off hive ships with regular rounds or las cannons.

Knockagh wrote:

 Psienesis wrote:

Knockagh wrote:
I'm sure there is an answer to this somewhere. Why can't imperial vessels just fire an exterminatus into the nid fleet and wipe them out with great ease? Surely the hive mind would be unable to adapt to the virus quickly enough to save itself?

Most methods of Exterminatus require some other agency to be present to work, such as an atmosphere to ignite, biological matter to convert into a flammable substance, or the crust and core of a planet to detonate.

Throwing a Cyclonic Torpedo at a Hive Fleet might kill... one ship. There's millions to go.

Fire a few more then! Surely it more effective than trying to blow chunks of meat off hive ships with regular rounds or las cannons.

Try Macro Cannons and Lance weapons (huge oversized lascannons).

Nid fleets are very big and very very long. Plus if you use anything nuclear and you do not totally blow it to bits, there is a chance that irradiated chunks of nid flesh might fall out of the sky towards nearby planets. Tyranids are capable of surviving an exterminatus anyway, so Emperor knows what might crawl out of that wreckage.

Knockagh wrote:

 Psienesis wrote:

Knockagh wrote:
I'm sure there is an answer to this somewhere. Why can't imperial vessels just fire an exterminatus into the nid fleet and wipe them out with great ease? Surely the hive mind would be unable to adapt to the virus quickly enough to save itself?

Most methods of Exterminatus require some other agency to be present to work, such as an atmosphere to ignite, biological matter to convert into a flammable substance, or the crust and core of a planet to detonate.

Throwing a Cyclonic Torpedo at a Hive Fleet might kill... one ship. There's millions to go.

Fire a few more then! Surely it more effective than trying to blow chunks of meat off hive ships with regular rounds or las cannons.

Most Imperial vessels are not equipped to deliver Exterminatus-grade weapons (this being the purview of the Inquisition), and ships that perform this task don't often carry more than one such weapon. This is not a thing done lightly...

There is also the problem that any Hive Fleet outnumbers any Imperial Fleet millions to one.

Xyptc wrote:
Plus there is always that nagging fear that using the Life Eater virus against the Hive Mind will allow the Hive Fleet will adapt to the Life Eater virus, or worse yet build a controlled version of it into its own arsenal...

I believe the post on adaptation to the life eater virus is dangerous. As Tyranids evolve, they get more resiliant to diseases. I read a fluff that the nids were able to adapt and overcome diseases spawned by a greater chaos daemon prince of Nurgle ie great unclean one.

If that bit holds true, then its dangerous to use virus bombs on a hive ship. The bugs may lose a ship, they may gain a weapon. That and plot armour.

I might have misunderstood what you mean by fire an exterminatus into the tyranids? I thought an exterminatus was just an expersion and the way it was handeled varried (carpet bombing or a virus that eats everything.)

In the tyranid fluf they manadge to winn one battle with a virus but it failed the next time. (6th edition codex.) There was the dawn of war example I listed earlier.

As for just blwoing them up with a big bomb, is that not what a space fight would entol? I am shure the imperium try this whenever there is an apt opertunaty.

 Niiai wrote:
As for just blwoing them up with a big bomb, is that not what a space fight would entol? I am shure the imperium try this whenever there is an apt opertunaty.

That is pretty much what nova cannons and torpedoes are for. However, the Tyranids are one of the hardest things to fight in space, They have giant claws that can cut spaceships in two, or grab them and inject them full of swarms. In fact, in BFG, Tyranids are the only enemy that you can voluntarily breech your warp drive against when they board you: the "All is Lost" rule. Lord Admiral Zaccarius Rath did something similar during the Battle of Macragge. He took his flagship, the Emperor class Dominus Astra, into the centre of the Tyranid fleet and detonated the warp drive. This destroyed the fleet and saved the planet.

I imagine it's a question of how concentrated their forces are. Out in space they're probably spread out over large distances, making it difficult to wipe them out with explosives. If one waited for them to focus their forces around a planet, one could hit a large number of ship with a cyclonic torpedo detonation.

If your plan is to save that planet, though, you're not going to do that.

Don't recall exactly but I think the 3rd edition codex said the exterminatatis down against Tyranid worlds was done by torpedoes that set the atmosphere on fire. Does not work in spaces as there is no air to cause a chain reaction with a single shot.

There is a little blurb on page 87 of the BFG nid PDF that specifically refers to shooting virus bombs at the hive fleet.

Link: http://www.games-workshop.com/MEDIA_CustomProductCatalog/m2350032a_BFG_Necron_and_Tyranid_Fleets.pdf

Basically the Nids quickly become immune and then use the virus themselves, as was suggested earlier in this thread.

The thing is that the Virus burns itself out pretty quickly if it doesn't have anything to eat away at. So while the nids it directly hits will be toast, the other ships nearby will simply pull back till its burnt out. Which will be fairly quick.

There is nothing to spread the virus among the fleet and so its blunted.

You need things on the order of Nova Cannons to have super weapons that can destroy the Nids.

Well for one the Imperium would take a century to send an Exterminatus fleet to the hives and the fleets really only excel at destroying planets unless you're willing to spam virus bombs at point blank range and detonate half the fleet's reactors. On top of that the main Hive Fleet has still yet to enter the galaxy.