Soon enough my players will be entering the theatre of war, rather than small missions. They'll be in the forefront of a Tyranid assault, and other than the standard Tyranid assault tactics that fall from their infiltration spores into a large spread landing that then starts terraforming the planet surface until their ships start assaulting, and I was thinking of having a few irregularities, some that I thought I'd share and see what the general consensus of GMs would be about differing evolutionary tactics.

Instead of the standardised assault, the assault on the outer planet of the system, a large gas giant, will be consumed in order to create a poison powerful enough to wipe out the population of the second planet, and without pausing to consume it onto the next planet, unleashing the same poison, and then starting to consume.

The second and third planets will become the war zone my players will be fighting on, concentrating on eliminating capillary towers, harvesters and spawning pools, and possibly assault hive ships themselves.

When it comes to it, the primary genetic make-up of these particular Tyranids is an injection of poison in claws, teeth and their living weaponry. The poison itself forms into a parasite that feeds on the cells of their victims and eventually grows into new Tyranids, that devour their hosts from the inside out. For this reason, the Hive Fleet doesn't kill their enemies, instead they impale them upon thorns grown from their back, leaving them to die slowly.

I was wondering whether any other GMs had other such ideas involving the unique flavours of the Tyranids?

This sounds like an interesting topic. I'll make sure to be back but right now I don't have many good ideas that would stand out from the rest.

I've tweaked tyranids for confusion/interest/surprise, but nothing to the extent you've proposed (yet) - very nice! I've had to alter things to keep tyranids surprising for the players; but a whole hivefleet of poisonous and cruel tyranids...could even have the beginings of a tyranid/nurgle conflict/campaign! (and the obligatory Deathwatch/Grey Knights team-up, if yer into that sorta thing...)

Darmort said:

My only concern is that you have the Tyranids wiping out the things they care most about on a planet; the populations. Nids eat people, both for biomass and to harvest divergent genetic strands. If they kill all of the people, and then move on to the next world, those DNA sources will degrade, and the Tyranids will be without improvements. Having a large source of minerals and biomass is nice, too, but if they don't get to eat any of the DNA, then they missed the chance to get that one in a million mutation that might have warranted formulating a new strain. Large-scale gassing also seems like it would be a bit difficult to stop, even for Space Marines.

Hmm, as I keep reading, perhaps I oopsed, but I don't feel like erasing it all. I pictured this more as a giant gas chamber-scenario, when it is more of a super-toxic Nids running amok approach. In hindsight, this idea has some merit, and also does add a bit of a difference to the usual "Zerg rush tramples outlying settlements, reaping up to the capital"; a very genestealer feel to it. A second thought, and one that could work out intriguingly, would be a variant on the Genestealer Cult. It might be interesting if the capital world of the system was infested with some type of near-Human Tyranid, and they had corrupted the governing body. This could assist them in their consumption, as it explains why the swarm hasn't met other ships. Whether the players, or Ebongrave, are aware of the origin of these leaders could cause twists, as either they know, and he doesn't, and he interferes with their efforts to eradicate the infestation, or he knows, and they don't, and his weird personality throws the players at governing leaders without knowledge why. I'm sure that, since the Deathwatch now has a level of independence it used to seem to lack, there's only so much Ebongrave can do either way, but a three-way clash between the players, the Salient's Overseer, and the incognito Nids could be very interesting, at least to me, and definitely fly in the face of "standard" Tyranid tactics; kind of give them more of a "thinking man's" approach, over the usual Zap Branigan slightly smarter, "we'll throw wave after wave of our own men at them, until they fall from tripping over the bodies of friend and foe".

How about this, perhaps a bit corny but it might work and give your players some horrid insights:

As you said the poison itself becomes a living thing, a parasite.
A powerful (primaris) psyker is poisoned but because of his psychic power he does not become a host but he evolves and himself into something new.
That NPC could be a living breathing mouth for the hive mind.

Okay this is two parts Resident Evil and one part Starcraft but 40k has been build upon other settings...

Kerrigan anyone?

oooh....that's a good one, Santiago! And could the possessed psyker also be a player character? This thread's startin' to become nasty indeed....

Gas Giants really aren't a good target for Tyranids, they go for biomass which Gas Giants aren't really known for.

The parasite idea would be interesting as it could be intergrated from a xeno fungus on the first planet they encounter, and progress towards a suicide spore. ( Kill a nid and it releases a spore cloud of parasites.)

Except, Bait, for gas giants that are heavily populated by cloud-dwelling filter-feeding critters of massive size!

I think it should be written in the basic rule book that it is the sworn duty of every Gamemaster to change Tyranids in new ways each and every time the Kill Team meets them. After all that is kinda the point why the Tyranids ARE so dangerous: Because you never know what to expect.

It's less about the consumption of biomass in that case, Bait, than it is about the forging of a weapon with which to consume bio mass. Whoever said that Tyranids have a one-two approach to a problem.

Besides that, somewhere there is a hive ship that devourers gas giants in order to turn the gasses into biomass.

I had thought about the Kerrigan route, although I decided for this gene make-up it would be a bit obvious. For one that focuses more on the dynamics of stealth, subversion and then eventual bring round the submission of the planet via the planetary governor being infected, then it would work. However, this would almost certainly be fluff heresy and bring around the wrath of my local Tyranid authority.

Unfortunately, the Tyranids as a whole do not need a voice. They are the swarm and the great devourer. What are they going to say, "Why, nice to meet you mister human, I'm going to bite your legs off now with a spot of biomass. Om nom nom."

I confess, I like my aliens completely unrelatable so I'm not a fan of the Kerrigan route. I DO love the idea of a Hive Fleet coating the moons surrounding gas giants with untold quadrillions of tyrannic bacteria and hurling them into Gas Giants, allowing them to start refining the hydrogen atmostphere into Silicane for weapon systems. Having a Hive Fleet that's largely bacterial in nature? That's horrifying on so many levels. People are okay with the idea of poisons - if you want to scare a player, use disease.

This is a link to a Fungi that might provide some inspiration for a bacterial take over. Imagine - hordes of Imperial citizens that have been infected, each patiently queuing up alongside every other mobile creature on a planet to hurl themselves into a digestion pool.

scienceblogs.com/neurophilosophy/2011/03/return_of_the_brain-manipulating_zombie-ant_parasitic_fungi.php