Warhammer 40K 3rd/4th edition rules misc analysis thread

[Connor MacLeod]

Well, as I said before, I've decided to branch out some of the "misc analysis" into more digestible portions (or at lest more easily researched, with whatever the rest I have) So this marks the beginning of the roughly 3rd/4th edition material.

I'll probably leave this first post open simply for acrhival, as at some point I doubtless will go back and mark it up with links to the posts as it gets bigger. Hoppefully it will be easier to work with. and maybe at some point I'll break down the original misc thread.

[Connor MacLeod]

Tyranid codex 2001 (thats how I think of it at least.. so I'm guessing 3rd edition.)

Page 2

The Tyranid hive fleet consists of millions of living craft, each home to billions of creatures.

Size and scope of a Hive Fleet.

Page 2

The highest forms of Tyranids, their Dominatrixes and Norn Queens, are living bio-facotries which give birrth to an unending stream of warrios, hive ships,and symbiote weapons.

really, self-explanatory.

Page 8

The symbiote [venom cannon] fires using an elctro-static charge to accelerate its deadly ammunition to supersonic speeds.

Some Tyranid weapons are supersonic (if not hypersonic)

Page 8

Wherever the creature [deathspitter ammo} strikes, gobbets of volatile fluid are spattered across a wide area, searing through exposed flesh and melting through armour with equal vigour.

Not sure if "melting" is literal here, but I doubt it. Then agian if th eliquid IS volatile, it might release heat via a chemical reaction. No reasion that Tyranid organisms couldn't be some sort of explosive weapon.

PAge 8

The spinefist launches a salvo of diamond-hard spines coated with a lethal neurotoxin ina broad pattern when stimulated.

Presumably it has projecitle properties as well as the poison (again suggesting high velocity like the venom cannon.

Page 8

Rending claws are short and powerful, tipped with diamond-hard spieks or talons. They are quite capable of crushing plasteel and ripping through the thickest armour with their vise-like grip.

Capabilites of Tyranid claw weapons.

Page 9

These [flesh hooks] are formed out of carbon-based chitin with a monomolecualr edge attached to lengths of exceptionally tough muscle fibre situatied between a creature's rips.

Tyranid claws are monomoecular like Imperium blades. One may presume psychic warp magickery to be the cause.

PAge 10

Some among the Magos Biologis even whisper that the Tyrant Guard contain DNA from Space Marine chapters lost to the Tyranids

The idea that Tyranids have space Marine DNA to mess around with is rather unpleasant, though I'm not usre it would drastically alter their abilities from what they already have (fast healing, toughness, super speed and stength, ,etc.

Page 13

Termagants have been known to be expended by the thousand merely to exhaust the defenders' ammuintion prior to a major assault.

..

In the final phases of a Tyranid invasion, billions of voracious Tyranid organisms are released over the planet.

...

Eventually they [organsims] are reabsorbed by the hive fleet and their biomass used to create more complex creations.

A bit on Tyranid tactics. They basically amount to human wave but... they can afford to.

Page 39

A billion times a billion tyranids stand at the rim of the galaxy, each one no more than a single cell in the living body of the hive mind, the devourer of worlds.

a quintillion Tyranids. Again, not very pleasant to consider.

[dragon]

Damn thats a lot, no wonder the Imperium has a hard time with them.

[Connor MacLeod]

That's not all, if the ratio scales up for warships, there could be trillions if not quadrillions of hive fleet ships (all types) total.

And that may not even include all the various worlds they've pillaged (dozens? hundreds?) That much biomass could easily rival or exceed the sheer mass of the DS2 (by orders of magnitude)

[Coalition]

That's not all, if the ratio scales up for warships, there could be trillions if not quadrillions of hive fleet ships (all types) total.

And that may not even include all the various worlds they've pillaged (dozens? hundreds?) That much biomass could easily rival or exceed the sheer mass of the DS2 (by orders of magnitude)

You mean like this:
http://uk.games-workshop.com/tyranids/t ... -worlds/1/

Dalki-Prime was an agricultural planet with a diameter of 12,500 km, slightly smaller than Terra. The Tyranid fleet was able to remove the following quantities of material from the planet within 100 days [Terran Standard].

1.55 billion cubic km water, one cubic km of sea water weighs over 1 trillion kg.
8.67 billion cubic km gases, at STP theoretically they could reduce this to 1 tenth its volume by super cooling and pressure (3 atm, and 0ºC).
72 million cubic km soil and minerals, weighing 1.4 trillion kg per cubic km.

From one planet.

[The Grim Squeaker]

You mean like this:
http://uk.games-workshop.com/tyranids/t ... -worlds/1/

Dalki-Prime was an agricultural planet with a diameter of 12,500 km, slightly smaller than Terra. The Tyranid fleet was able to remove the following quantities of material from the planet within 100 days [Terran Standard].

1.55 billion cubic km water, one cubic km of sea water weighs over 1 trillion kg.
8.67 billion cubic km gases, at STP theoretically they could reduce this to 1 tenth its volume by super cooling and pressure (3 atm, and 0ºC).
72 million cubic km soil and minerals, weighing 1.4 trillion kg per cubic km.

From one planet.

The conclusions are that the vast (over 90%) percentages of the biomass is sent out of the galaxy with only a minor amount being used to feed warriors and to create new warriors, let alone ships, no? (My knowledge of Nids is lacking, as has been seen before, but we haven't seen the explosion in Nid numbers that would result from even a few dozen worlds being stripped, and there is an in-universe quote about most of the biomass being sent...somewhere. Which raises truly hideous prospects of how large the Main Tyranid race if all that biomass is needed just to feed it)

[NecronLord]

If we take Ian Watson's Space Marine as evidence we know that tyranid vessels contain considerable volume in the warp, potentially explaining how precisely they shift all that volume around.

"72 million cubic km soil and minerals, weighing 1.4 trillion kg per cubic km." is presumably an error, though. I assume this is maybe the total mass.

[Luzifer's right hand]

If we take Ian Watson's Space Marine as evidence we know that tyranid vessels contain considerable volume in the warp, potentially explaining how precisely they shift all that volume around.

"72 million cubic km soil and minerals, weighing 1.4 trillion kg per cubic km." is presumably an error, though. I assume this is maybe the total mass.

Why? That's 1400 kg/m³
Soil is denser than water after all, it seems a little low in fact.
Or are you surprised that someone seems to understand the concept of volume and density in the land of foamships?

[Connor MacLeod]

More on the Tyranids,, plus some calcs!


Page 40

In their [hive fleet] wake was left a bare rock orbiting a star, scoured of every organic particle, stripped of all but the most basic elements. Nothing was left of the farming world of Langosta III, there were no testmaents to the humans who had once lived there. Now all that was left was an airless asteroid, the unmarked deathpalce of three million people.

The results of Tyranoforming a world. Tyranids don't take out organic matter, they take a great deal more (Silicon one imagnes, because their carapaces are silicates/ceramic-like) but also water and air.

Page 41

Discovery of potential targets is undertaken primarily by warp-capable scout drones which disperse among the star systems close to a hive fleet. Over the course of decades these living ships methodically investiage plantes, and upon discovery of likely canidates, seed worlds with "vanguard" orgasnisms such as Lcitor and Genestealer infiltrators and various Gaunt species.

It is believed that the psychic signature of these creatures draws the hive fleet to them proportionally to their numbers.

What we could term the "hunting methods" of Tyranids. Infiltration plays a big role, of course

Page 41

Likewise, Genestealer infestations are commonplace enough that the High Lords have issued no less than eighty decrees pertaining to their cleansing by Exterminatus in the last decade.

They've rendered Exterimnatus on eighty genestealer-infested worlds, presumably as a preventative measure to keep the tyranids from homing in on those territories.

Page 41

It is believed that the hiveships perform some form of spectrographic analysis of the radiation from the nearest stars to select a destination.

Another means of huhnting. The Tyranid hive mind (or at least the hive ships) are intelligent enough to "scan" for nearby stars that could support habitable planets.

Page 41

The bio-ships which comprise the fleet may either exit the warp simultaneously at the edge of the system or, in many reported instances, exit in deep space and drift towards their objective. This latter approach renders the hive fleet virtually invisible to long-range augury and astrotelepathic detection.

Note that the Tyranids may gof or a stealth approach ro a direct approach (presumably depending upon time availabe and circumstance.) Also note that augur sensors can detect warp transitions (And astropaths can function as a form of detection system.)


Page 41

There has been some speculation that some hive fleets may actually drift through realspacee for the entire voyage between systems, but as this would entail a journey time of (at least) centuries in hibernation it must be consigned to the realm of conjecture.

Here the idea that Hive Fleets travel purely by realspace movement between systems is absurd. The durations of travel (centuries) suggests many scores if not hundreds of light years average between Imperial systems.

Page 41

The mix (of spores dropped onto the planet) typically include mycetic spores for landing 'vanguard' and 'main force' ground assault swarms, spore 'mines' of a corrosive, poisonous and/or explosive capability, zoomorphic symbiotes and parasites, plus fertilisation, weather modification, and necrotic variaties.

Flying creatures are also dispatched in great numbers, primarily swarms of winged Gaunt species tended by the dropship-sized Harridan brood organsims.

Description of the methods and tactics involved in a Tyranid bombardment. We can say in broad terms they engage extensively in chemical/biological warfare. They also employ drop pod-style and drop-shipt assaults and orbital bombardment. This doesnt even include the "infiltration" aspects of their attacks (Destabilization)

Page 41

As resistance is overcome more and more of the planet's surface is stripped bare by continuous harvesting until the hive fleet concludes its actions by draining the planet's atmosphere and seas. AT this point many hiveships will calve, adding to the fleet's numbers of drone-vessels and immature bio-ships.

STripping the air off a planet requires 3e26 joules of energy. STripping the ocean off requires something on the order of 9e28 joules of energy. actual power generation figures depend on time and number of ships, but even then this gives us a broad indication of their power (and by extention, Imperial capabilities)

PAge 42

They [Tyranids] would strip away its atmosphere and drink its oceans, covering their mile-long bodies with frozen sheaths of oxygen and hydorgen, nitrogen and chlorine in preparation for the journey ahead.

...

"You led the Cobra squadron to Tethris and participated in the Exterminatus."

"Aye, though there was little honour in dropping out of the warp to launch cyclonic torpedoes and then fleeing."

...

"They actually managed to block a third of our torpedoes but the rest hit cleanly. I saw the fire vortexes spread and multiply. The planet burned."

****************

On Tethris, an endless ash-plain shifted and then cracked apart as the first of the newly pupated rippers burrowed its way up to teh surface and hissed its definace at an empty sky.

Various points of interest:

- "Mile long" tyranid vessels. No idea of what they are, but it may be implied to be hive ships (small ones?) Again they strip off the water and atmosphere of the planet. Interestingly, they "sheathe" it around themselves, suggesting they not only can expend the energy, but absorb huge quantites as well.

- Cobra destroyers (if properly equipped) can conduct exterminatus operations as well (which seems to be an exception to the BFG-oriented rules) Presumably the weapons are fired out of hte torpedo tubes. (If there are about 6 8 destroyers in a squadron, there were probably between 20-30 torpedoes, tops, if they fired only one salvo.

- The Destroyers launched upon exiting the warp. This can mean one of two things. Either a.) the Destroyers dropped out of teh warp some distance in system before launching (possible, but unlikely) or b.) they launched from some distance away (probably the edge of the system.. many AU off) and targeted the planet. This seems liklier, as we already know of long range bombardment examples, and this simply reinforces that torpedoes and missiles can engage at extremely long ranges (millions or billions of kilometers)

- We dont know for sure if these are technobabble cyclonic torpedoes or brute force ones, but the latter (Based on TActica Imperialis) seems liklier. The fact it triggers firestorms and needs multiple warheads seems to suggest this, ,but its not certain The effects are pretty straightforward though - they trigger global firestorms and basically heat the atmosphere to what can be termed sterilization temperatures. The fact that it basically incinerates everyhting on the surface of the planet suggests this (cremation temperatures are in excess of 1000-1200K) Generating those levels of energy would requier billions of megatons easily.(5e18 kg of air on an earthlike planet, about 1.2 MJ per kg to heat the atmosphere to 1500K) This does assume high efficiency, so it could be alot higher, but probably not massively so since its purpose-built for "airburst". The fact that a Tyranid can burrow undeground to avoid the attack also reinfores the airburst nature of the attack.

This also means each cyclonic torpedo generates hundreds if not thousands of teratons.

[NecronLord]

If we take Ian Watson's Space Marine as evidence we know that tyranid vessels contain considerable volume in the warp, potentially explaining how precisely they shift all that volume around.

"72 million cubic km soil and minerals, weighing 1.4 trillion kg per cubic km." is presumably an error, though. I assume this is maybe the total mass.

Why? That's 1400 kg/m³
Soil is denser than water after all, it seems a little low in fact.
Or are you surprised that someone seems to understand the concept of volume and density in the land of foamships?

No, I read it as 'per cubic m' when I wrote that.

[Connor MacLeod]

This time around.. Tyranid durability. I may have to write up a bit more about that sort of as a "synopsis" like I did with Tau tactics, becuase I have known the Tyranids to be brought up as an example fo the Imperial Guard being "inferior" to modern forces (usually nuke-wanking)

Anyhow, read it closely, beccause there's alot there

Page 46

Preliminary attempts to classify the biology of the creatures met with considerable difficulty due to the existence of multiple redundant systems for respiration and circulation. Skeletal systems were internal as well as external thus allowing for little internal space but providing exceeptional resilience and strength.

Part one reason why Tyranids ar eso damn durable - they have redundant body functions (liek a space marine) as well as a double skeleton (External and internal)

Page 46

-External Carapace thickness increases exponentially with increased body mass.

- Internal skeleton density likewise increases with body mass.

- Substnatial mass percentage allocated to structural s upport in larger organisms (leads to significant natural armour and resistance to damage)

...

This [Phage cells] render many, if not all, standard poisons inefficient and lessons the effect of any structural damage.

Note that the text describes the Phage cells serving as what passes for a digestive system in the Tyranids (absorbing a preprocessed liquid provided from the Hive ships) They also neutralize the poinsons.

"exponetnail increase" in carapace thickness would be useufl if we knew dimensions REgardless it tells us the bigger the tyranid,its vastly tougher. Their muscle and skeletal strcutures also allow them to be far more heavily armored.

Page 46

In combat and periods of heightened activity the symbiotes pump the adrenaline by-products into the host creature, significantly heightening agression and reflex speeds.

Chemical boosting (like a IG Gland warrior).

Cutaneous diffusion on sacklike simple lungs with many symbiotic bacteria (Allows adaptation to nearly anyy atmosphere.)

..

Digestive system: None [see Phage Cells]

again, mentioning of the internal ystems and wht passes for digetion.

Ocular organs:

No Palpebrae. Hard exterior.

- Vulenrable to high intenstiy light over compensation response 'flash blinding" quick recovery.

Tyranid equilvaent of flash protection against glare.

The lack of any discernible liver, kidneys digestive tract and other glands allows the creatures to use this valuable biological space to house additional defenses, muscle and redundant systems. It is very difficult to kill a Tyranid without inflicting significant damage to several systems unless the central nervous system si severely damaged.

The Tyranids are extremely specialized combat forms. They woudln't last long outside the supply and support of other Tyranid forcees (they couldn't "live off the land" without Tyranid intervention), but it gets rid of alot of unnceessary systems (and potential injruies) and allows for enhancement of overall capabilities (especially durability). This specialization is one reason more that Tyranids are very hard to kill (unless you get a lucky shot, or aim well) It also tends to suggest that precision weapons will work better than area effect weapons (unless the area effect weapons are very powerful, like plasma and meltaguns) Tho powerful shrapnel attacks (artillery) probably could still work (if they hit enough weak points/gaps)

Page 46-47

As new genetic information si gained, this in turn is relayed to the metamorphosing creatures in a process similar to that of the Space Marine Omophagea. In t his way they are able to adapt to new atmospheres and poisons very quickly by making modifications to their own metabolism while still in the developmental stage.

Tyranids can be adapted to their enviroments they assault as they are grown. This allows the Tyranids to be tailored to their particular roles and enviroments better.

Page 47

The toxin [Tyranid] is a mixture of highly reactive inorganic poisons, haemotoxins, allotoxins, neurotoxins, acidic nodules and phage cells.

Within the Space Marine's body most of these are dealt with quickly but it appears that the phage cells are very destructive very quickly, seemingly being excited to action by the body's attempts to destroy them. They mimic the outer surface of native cells and set about destroying anything they encounter. They do this by locking onto receptors on the outside of the cells and then releasing a matching permanant block onto them shutting down the cell's function

This damage in effect sense the Larramans cells into overdrive causing blocked blood vessels on a bodily scale.

Tyranid "poisons" and their naturea dn effects, particularily on space marines.

PAge 47

The surprising biological durability of the Tyranids is of direct interest to the Forces of the Imperium. What follows is an analysis of Tyranid biologicla defenses to projectile and directed energy weaponry.

...

Musclar: the muscular sheath within all the creatures of the hive fleets (known) exhibit cross-threaded fibrous nature which is as effective as standard issue Flak Armour. Primarily defensive against projectiles, this is a major factor within the organsim once primary defensive chitin and tissue have been breached.

This presumably refers to "soft" flak, in the sense it resists weak energy and projectile imapcts (laspistola dn autopistol) and mitigates the damage of stronger ones (lasgun/autogun). This will also probably indicate the durability of weak points.

Skeletal: The thick external chitin shells, coupled with the internal dense silicate-rich skeleton offer a high degree of protection from both energy and projectile weapons. THe outer carapace is baffled with internal cysts containing "Tyrgel" a viscose organic liquid (92,987 cps) with astounding thermal capacity.

The design and composition of the skeletal and carapace structure. ITs thick, its partly silicate (much like Space Marine skeletons one imageins) and has internal "Heat sink" Tyrgel liquid that serves both cushioning agianst blunt force attacks and thermal resistance to energy fire.

Directed energgy weapons are unlikely to cause lethal damage through these areas without being of an anti-armour nature. The protection afforded by the chitin itself is proportional to the density and thickness ranging from 5-14 Moh. The "Tyrgel" also depletes the inertial energy from projectile and fragmentation weapons. All Tyranicus Tyranicii, Tyranicus Cruentusea and derivatives are exceptioanlly durable and contain the highest percentage of these cysts. Overall bio-mass density gradient 1.659 with significant proportions allocated to skeleotn [human c1.175]

Various points:

- While it says that you need "anti armour" ot penetrate the carapace, I daresay this depends on the Tyranids. I doubt a 'gaunt would be very resistant to krak grenades, for example (A warrior may or may not, though.) But it probably will serve as an indication that most conventional weapons will be minimally effective (or totally ineffective) against the carapace (lasguns and autoguns, but perhaps even bolt weapons would be less effective, especially with combined with the other physical aspects of Tyranid toughness.)

This also means, like with the Orks, you need to use precised, aimed shots to injure/kill Tyranids, and this is almost always what we see in novels (eg Warrios of Ultramar.) targeting the weak points - possibly on higher settings to insure a kill. The need for accuracy and power also probably means that the effective range at which Tyranids can be engaged is much less than other targets (probably elss than Orks even.)

- "Moh" may refer to the "Mohs" scale of hardness, mentioend here and here[ and here and here If you read the links, you'll notice it gives both "mineral" strengths and comparative strengths of other objects, which may give us a broad idea of toughnes of the carapace (and further reinforces the kinetic toughness.) Presumably the "5" will refer to the weakest forms, but the 14 the strongest (which is off the scale."

- The "Tyrgel" is mentioned here to be a "cushioning" agent against kinetic attacks as well as a thermal heat sink. One imagines if the carapace is punctured, they may also serve cooling and/or ablative functions as well.

- Density wise, if it is referring to g/cm^3, may indicate that Tyranid organisms are significantly denser than humans (1.6 g/cm^3 as opposed to 1.1 g/cm^3.)

Enzemic: Phage ceclls neutralise any poisons and/or biological attacks. They are also capable of releasing an enzyme that will polymerize the "Tyrgel" upon exposure. This occurs whenever the cysts are ruptured and seals the breach with remarkable efficiency, to avoid the loss of essential bodily fluids.

Poison resistance, and rapid healing akin to Space marine Larraman cells.

Biological function: As described elsewhere the redundant systems of respiration and ciruclation, coupled with the lack of digestive systems within most Tyranids allow them to sustain extensive nonlethal damage. Termagauntus Termagauntii have been seen to survive the laoss of all limbs iwhtout expiring due to fluid loss [see enzemic entry] Many may function for hours or days with severe thorasic damage and may fully recover from seemingly lethal wounds.

Again, extreme durability due to specialization and redundancy. When coupled with their heavily armoured nature, its small wonder they're so hard to kill. Examples here give an indication of just how tough they are (compariable, it would see, to a Space mArine or at least a heavily augmetic human)

Intense radiaiton [ref: Cobalt bomb] is effective in planetary applications but hive fleet structures are biologically defended by as yet unknown means. Thus it is within the evolutionary scope of the Tyranids to cope with this threat.

Lesser Tyranids CAN be killed via intense radiation bombardment (the Imperium knows of cobalt bombs) but ineffecitive against larger enemies. Presumably, though, this hasn't been used extensively becuase, due to the scope of Tyranid attacks (billions of organisms), the bombing may be extensive enough to threaten the attacked planet (nearly destroy or destroy the ecology, for example.) In such cases, it would probably be simpler to use Exterminatus (and as we know with Kryptman, that isnt always seen as the answer to the Tyranids.)

Carapace areas should not be targeted, except by anti-armour weapons. Eyes, neck, and joints are the weakest areas of nearly all Tyrannidic organisms. However extremity damage is unlikely to ever prove lethal except in extreme instances.

The recommended tactics for engaging Tyranids. Again, we note that carapaces are considered ineffective targets except for fairly heavy weapons. WEak points are the soft points, but even here their toughness/redundancy means that certain weak points (IE limbs) won't guarantee a kill, so eyes/neck seem to be the likliest locales.

Which in practical terms means that like with ORks, you go for a headshot.

[CaptainChewbacca]

If Tyranids are this nasty and numerous, how are we gonna stop them? What do we do if the whole RACE comes after us?

[Ender]

Page 46

-External Carapace thickness increases exponentially with increased body mass.

- Internal skeleton density likewise increases with body mass.

"exponential increase" in carapace thickness would be useful if we knew dimensions Regardless it tells us the bigger the tyranid,its vastly tougher. Their muscle and skeletal structures also allow them to be far more heavily armored.

That doesn't make any sense. Body mass should increase exponentially with increase in carapace coverage, not the other way around. Double the size of something and you increase its volume by 8. Doubling the body mass to get an exponential increase in thickness means that the body mass should rocket up again because you just jumped up the volume of the armor. This statement as written would require larger creatures to have ticker armor, but exponentially much less of it to keep the mass following the change defined.

[Vendetta]

If Tyranids are this nasty and numerous, how are we gonna stop them? What do we do if the whole RACE comes after us?

Everything in 40k is that nasty. It's part of the setting.

[Coalition]

That doesn't make any sense. Body mass should increase exponentially with increase in carapace coverage, not the other way around. Double the size of something and you increase its volume by 8. Doubling the body mass to get an exponential increase in thickness means that the body mass should rocket up again because you just jumped up the volume of the armor. This statement as written would require larger creatures to have ticker armor, but exponentially much less of it to keep the mass following the change defined.

I'd see it as endoskeleton and exoskeleton increases in strength. The armor/exoskeleton is increasing faster the larger the critter gets in order to support the weight, but as a side effect it gets better armor.

Of course, this means that if you can crack the exterior armor in the right places, the critter will collapse under its weight. In combat that would be less likely (due to the fact the critter is shooting back at you) to accomplish.

[Connor MacLeod]

That doesn't make any sense. Body mass should increase exponentially with increase in carapace coverage, not the other way around. Double the size of something and you increase its volume by 8. Doubling the body mass to get an exponential increase in thickness means that the body mass should rocket up again because you just jumped up the volume of the armor. This statement as written would require larger creatures to have ticker armor, but exponentially much less of it to keep the mass following the change defined.

From how I read it, ,I assumed it was an attempt to improve localized protection at the expense of overall protection. IF you want to add more armor, you can either cover more locations, or better cover specific ones, such as the vitals. To do the latter will apparently involve either making the armor denser (which may have undesirable side effects on a Tyranid if its done too much) or to make it thicker.

Yes, increasing the area of coverage would also increase the mass, ,but that would impair mobility since those carapace plates are going to be pretty rigid. I should note that by IA4, Tyranids are already pretty bulky, many times the mass of a normal human even for the smallest forms (Gaunts are ~200 kg, Genestelares are around 300 kg, and the larger forms like Warriors are nearly or at a ton or more in mass.)

This probably makes sense given how damage resistant Tyranids are (redundant organs self healing, backup "armor" even at weak points.) Alot of a Tyranid's body are going to be "non-essential" damage points, while certain other points will be vital, so stciking more armor over those to make them harder to kill would be sensible. Especially sincec alot of the weak points are joints and limbs, and we know damage to those don't stop the Tyranids.

[Connor MacLeod]

Rather than start the next Tyranid codex (yet), I'm going to do another quick synopsis of the Tyranid toughness bit, this with an eye towards the "modern tactics" wanking usually cited as proof of how inept the Guard is.

I have run across the Tyranids in vs debates where they are held up as proof that the Guard do not fight effectively against such a threat. Ususually, this largeyl amounts to nuke wanking, as if the US will somehow mystically mass-produce and issue Davy Crockett nukes and nuclear artillery and all that to Army units, or that such weapons would automatically wipe out Tyranid forces en-masse quite easily.

This, of course, ignores several factors. One of which is we know of at least one instance WHERE nuclear level yields were tossed at Tyranids (where the the Ultramarines fought Hive Fleet Behemoth) and megaton level yields got chucked at them from orbit, apparently with less than optimal effect.

There is also of course the existence of "nuclear like" explosives, like plasma and melta weaponry. Both of which can be artillery delieverEd (melta charges at least) and even have man portable versions (mines, rockets, even grenades.) Hell, even plasma and meltaguns count. For that matter, alot of their conventinoal explosives can easily reach into the "ton" range, making them close to FAEs or nukes already (and their equivalent of FAEs using Promethium are even more effective than our FAEs) And the fact they can use it as shrapnel (Again, arguably better materials science) can also make them deadlier (Shrapnel is better than radiation or just pressure alone.)

The main problem is, of course, how Tyranids are built and how they fight. They're fast, yes, and they have warpwank affecting them, but their main advantage is that they're highly adapted to human wave tactics. Consider the following:

- Tyranids don't care about losses. Moreover, losses don't matter, because the Tyranids always killa nd harvest organic matter on a defeated planet anyhow (Their own and the native shit.) So a corpse to a Tyranid is just another resource to use to create MORE soldiers. Sensitivity to losses is virtually nil, and as long as they have more organic matter, they can always produce more troops.

- as described above, they are (in 40K terms) exceedingly well armoured. While again I doubt you need anti-armour weapons to take out a 'Gaunt's carapace, they are without doubt exceedinyl tough. They can resist conventional lasgun fire well enough, at least. I imagine the lowest forms can be taken out by lasguns, I'd guess you need multiple high-power shots to penetrate the carapace. Lower power shots can probably damage the weak points (joints, eyes, etc where carapace cannot shield) but most probably save teh weak points in the head are probably useless.

Higher-ends probably can be breached by plasma and meltagun firem, although Carnifex or higher are resistant to even lascannon shots (as per 13th Legion short stories.), and we know Carnifexes can endure some form of exterminatus level conditions (cyclonic bombardments that superheat the atmospheres to cremation level temperatures.)

In terms of comparing the above weapons to nukes, it comes down larggely to one of intensity. That is, energy divided by area. (such as square meters.) lasguns tend to be fairly concentrated, a beam no more than a few cm in diameter, and can easily get into the single or double digit MJ Assuming, say a couple Megajoules, you can get a rough intensit of between .5-1 MJ per square cm, or between 5-10 GJ per square meter, depending on the exact output assumed. (At "high" power, which can be 10-20 MJ, you could expect the intensity comparison to be 25-30 GJ/M^3.

A 100 kiloton nuclear device at 50 meters would probably radiate several gigajoules of energy per square metre. These are very rough comparisons, but it does show that unless you are close to or in the nuclea fireball, or you use a very powerful devicec most Tyranids probably won't be seriously injured You probably could blow off limbs, or something, but probably not any serious danger.

Plasma and meltaguns tend to be less "focused" than plasma weapons, but they also have considerably greater outputs (meltaguns actualyl have variable focus, and can match/exceed the area affected of a potential nuke, but they can also be fairly focused also, but also prove the point- unles svery close or very powerful, a nuke won't do much.

I should note that MOST nuclear-level artillery is going to be alot lower in "tonnage" than the above. 20-40 kilotons for large artillery (8 inch) or rockets is what I can find, while most 155mm or smaller is goign to be in the sub-kiloton range, which will also affect those calcs.

There is still other factors, like blast. Blast as a kill mechanism is somewhat overrated, given that human bodies tend to be smaller-profile targets. Nonetheless, for a 100 kiloton detonation the blast radius of "near-total" fatalities, according to the SD.net effects calcualtor is 1.3 km (280m for a 1 kiloton detonation.) Offsetting this is the Tyranid carapace's sheer durability, the fact that Tyranids are many times more massive (and tougher) than a human for roughly the same profile (for most). Given their carapace bullet-resistance against most pistols and rifles, I expect they could easily withstand 20 psi or more without much effort, especially the larger ones.

Generally, you can say the same thing (broadly) about blast as about thermal effects - it needs to be close up to do any real (lasting) damage.

Radation.. we know it can affect them, although given that you need cobalt bombs to do it (dirty nukes, basically) I'm guessing it takes alot to do any lasting harm.

- Even assmuing you DO bypass the armor (which a nuke can do) there still is the problem that Tyranids are engineered to absorb and recover from extreme damage. Their redundancies, their tough bodies. The likely forms of damage to "Breach" are likely non-essential or parts of the body that are redundant (and better protected by the carapace), meaning that most Tyranids probably won't be that badly effected (loss of limbs, etc.) And that damage/pain will probably be at least partially mitigated or blocked out anyhow.

Worst case scenario is that a nuke will probably kill or cripple at most the weaker forms, but still leave the larger (and more dangerous) forms like the Warriors or Carnifex lagely undamaged unless you spam out alot of nukes (which you would probably have to do anyhow to wipe out large numbers of the smaller forms anyhow.)

End result is: nuke spam against Tyranids is going to be far less effective than it is against normal humans due to their protection and resilience, and as noted, ,conventional munitions available to the guard (up to and including melta explosives) will be on par with nukes anyhow (and their conveintonal/FAEs aren't that far below in terms of power either)

[Molyneux]

Er...just minor nitpicking, but maybe you should put a little hint into the title that this is 40k 4th edition, and not DnD?

[Ender]

Er...just minor nitpicking, but maybe you should put a little hint into the title that this is 40k 4th edition, and not DnD?

DnD would be in fantasy

Connor, I think you need to take into account the overpressure waves when evaluating nukes, not just energy intensity.

[Molyneux]

Er...just minor nitpicking, but maybe you should put a little hint into the title that this is 40k 4th edition, and not DnD?

DnD would be in fantasy

Good point. Sorry!

[Junghalli]

Has anybody ever tried to do any calculations of how many Tyrannid ships they could produce by eating the biosphere of a planet like Earth?

I imagine the need for carbon would probably be the limiting factor. Though they still drink up the entire ocean and atmosphere ... maybe they use it for propellant and fusion fuel.

Is there any description of what their propulsion systems are like? Imperial-style jawdroppingly efficient and powerful fusion rockets, or something weirder?

[Teleros]

Is there any description of what their propulsion systems are like? Imperial-style jawdroppingly efficient and powerful fusion rockets, or something weirder?

I can't recall ever seeing anything as to how the ships manoeuvre, but Connor may have something on it.

[Cykeisme]

The damage effect tables for Tyranid ship-creatures in Battlefleet Gothic actually provide a couple of clues toward this, actually.

The Critical Hit tables have an effect for "Discharge vents wounded". whereby it simply states that one of the "biological valves" that manoevre the ship is crippled due to enemy attack.
Based on the effect of the damage, these vents appear to be more for effecting changes in orientation, rather than thrusting for acceleration. Plus we still haven't the slightest clue as to the nature of what exactly is being vented, anyway.


Meanwhile, on the Catastrophic Damage table, there's a possibility that the carcass of the ship may experience a "Bio-plasma detonation".
Plasma is a bit of an over-used sci-fi term, to the point where we have no choice but to assume the fictional universe defines the term differently, especially since "bio-plasma" would in any other case refer to inert solvent fluids in a creature's body or somesuch.

However - I depart from our norm of disregarding game mechanics here -it's worth stating that the effects of a catastrophic "bio-plasma explosion" is not dissimilar to a comparably sized Imperial ship's "plasma coils" exploding. That is to say, a large ship exploding can cause significant damage to other starships in the vicinity.
If this is accepted as rules' author's intention for portraying the fictional universe, I would surmise that the power generation capabilities of a Tyranid ship are somewhere within an order of magnitude or two of the more conventional ships employed by other spacefaring 40k races.

[Connor MacLeod]

Connor, I think you need to take into account the overpressure waves when evaluating nukes, not just energy intensity.

I'd tried, but I'm not sure how exactly to compare the two. I'm at a loss for figuring that out.

Nearst I can manage is that their carapaces probably would be tough enough not to fracture against most overpressure (I figure its at least as good as Imeprial Carapace, meaning it can stand up to everything including .50 BMG and 20mm cannon fire) and that the internal organ redundancy/specialization and self-healing capacity would probablymean they're many times tougher than a normal human (Against overpressure, so they'd need to be alot closer to be harmed.)

and the larger forms are probably equal to Space MArines/Terminators/Dreadnoughts if not actual tanks, (Esp carnifex and up) so that becomes even more problematic. (Hell, ,as I'll cover, Carnifex and higher can survive global firestorms and incineration level tempreatures, so I doubt a nuke would do much to them.)

[Connor MacLeod]

Has anybody ever tried to do any calculations of how many Tyrannid ships they could produce by eating the biosphere of a planet like Earth?

Well if their organic shit is anything lke our organic bodies, they're going to be mostly water. I imagine given the aformentioend composition of Tyranids (They seem to be ceramic-baseD) they might use a fair bit of metal and ceramic as well (stripping these from planets, perhaps? referencing the Tyranoforming bit on the websites hints it may be so) but probably mostly water .

You have 1e21 kg of water on a Earth.

Assuming an average mass of around 100 million tons (1e11 kg) which is probably heavy cruiser/battleship mass for a 40K ship... you'd get potentially billions of warships. Mind you' there's more to it than just the water and the minerals and soil, but that may be what the "gases" bit means.

Mind you, that's very scary, but Tyranids build ships the same way they build infantry (largely expendable.) so there's a qualitative difference between a Hive Fleet's vessels and Imperial ones (offset by numbers and the fact I deliberately used heavy cruiser/battleship as a baseline, but its still there.)

More tellingly, we dont have any real comparison for how fast or slow they can build them.

I imagine the need for carbon would probably be the limiting factor. Though they still drink up the entire ocean and atmosphere ... maybe they use it for propellant and fusion fuel.

Propellant maybe, but I doubt they run any conventional reactors. They're probably powered by teh same "warpwank" (IE magic) that regular Tyranid troops are. (telekinetically accelerated weapons, engines, etc.)

Fun fact: Tyranids have demonstrated the ability to develop psychic shields. One of the "Let the Galaxy Burns" short stories had both tyranid ground troops with shields (a mutated Gaunt, IIRC) and a capital ship in another had geenrated some shield.

Is there any description of what their propulsion systems are like? Imperial-style jawdroppingly efficient and powerful fusion rockets, or something weirder?

Cyk covered this. It seems based on BFG they use reaction thrusters of some kind, although looking at the diagrams I can never find any obvious evidence of thrusters.

We can conclude they shoot shit out at high speeds, but its probably handled by warp-magic (like most things Tyranid are.) Efficiency wise? probably no better/worse than Imperial plasma engines, though I'm guessing the difference in quality means differnecese in power output.