Out of all the codices which were scene as disappointments in the 5th edition, Codex: Tyranids has a special place in people's hearts. Having been given to the tank happy Rob Cruddance, the codex felt like a major step down in many respects.
While they were made out to be a major threat, every major tyranid campaign concluded in failure and events seemed to go from one extreme to another. A tyranid victory would consist of a single Zoanthrope taking out an entire Eldar Craftworld, while a loss would contain some very ridiculous ideas and twists to end in their defeat. This is to say nothing of the problems on tabletop, with Carnifexes being nerfed and becoming overpriced for what they could actually do, and the strange new creations like Pyrovores which seemed to have little overall purpose. Seriously, no one seems to have any clue as to what this thing was supposed to do or why someone would ever want to take one.
To say the codex was extremely flawed would be a major understatement. It certainly wasn't in the same league as Codex: Grey Knights and its like, but it was up there. So beyond putting a writer who actually enjoyed covering tyranids behind the book, here's a few suggested improvements the book needs overall.
5 - Victories
As mentioned above, a major criticism of the last codex was how each tyranid campaign ended only in defeat. While the tyranids would ultimately take down huge numbers of the enemy, the fact they always lost robbed the force of a great deal of menace. The swarm should have definitely had setbacks and losses, Iyanden for one, but not for their accomplishments to be in the minority.
There are many ways in which the tyranids could fight the various races of the 40K galaxy and not require them to end in a major loss to try and preserve a status quo by inflicting defeat upon them. Even situations beyond the "tyranids turn up, people fight" situation the previous codex repeated. Perhaps an invasion against a world marked for scorched earth exterminatus by the Imperium, with the humans racing to destroy it, or a world in process of being conquered by a force which is anathema to them, the
Furthermore, not every victory they perform needs to be of massive importance or some open invasion. Even if it was only a conflict based around a single world or just Genestealers on a Space Hulk, Having experimental specimens escaping from a xenobiology facility into the wild and then returning in force, a tyranid scout ship stumbling upon a pirate base, even a story about a lictor stalking the halls of an Imperial Vessel leaving the battle. All of these can be told with just as much menace as any major battle and allow to show the threat tyranids can still pose even when not working as a swarm as they're so often shown. It would be an effective way to spotlight certain units, but hopefully without resorting to the ridiculousness of the Doom of Malan'Tai.
4 - Fix Carnifexes
This is one of the very rare occasions where something on this list will cover a specific problem with a single unit relating purely to tabletop rules. It's also one of the very few so far which was done so badly it requires a place on this list. While there is a great deal wrong with the codex in terms of overall rules, what symbolises the mistakes made was the treatment of the Carnifex. Originally a terrifying beast of a monster which was the go-to unit for any army in 4th edition, they were bullet magnets which should endure multiple lascannons to the face and keep going. The 5th edition unfortunately removed certain options such as their Extended Carapace upgrade, combined with a far higher basic cost and costs of upgrades nerfed the Nidzilla posterboy into the ground. Combined with their average WS, this made them vulnerable in close combat meaning tyranid players often seemed to reserve them as vehicle killers.
While the 6th edition has seen them get some well deserved buffs, a few changes are definitely still in order. Fixing their overall points cost would be a definite start, as would smoothing out certain rules such as their effectiveness in close combat and against fliers. While they shouldn't be restored to quite the levels they were at back in the 4th edition, the ability to not have a single power fist ruin is definitely a correction which needs to be made. This goes double for Old One Eye.
Carnifexes were known to be the goliaths of the Hive Fleets, borderline unstoppable and a major threat. They need to be that once again.
3 - The Enemy Within
Something all too often forgotten about the tyranids is that their fleets are only one approach they take. While the codex did represent some of their infiltration capabilities, they did not present it too well. The certain zoanthrope incident previously mentioned was one of the book's bigger offenders. While it tried to present the idea that a single tyranid is still a major long term threat, it represented none of the slow, methodical infiltration their forces were known for. The months of bioform infections prior to a Hive Fleet invasion and deployment of lictors as an advanced guard, the xenos corruption of populations, none of it was represented very well.
The very idea of a massive army swelling within a civillian populace, effecting every tier of society is easily as big a threat as the Hive Fleets themselves. As something brilliantly shown in the likes of the Ciaphas Cain books and Deathwatch (the novel, not the Fantasy Flight Games RPG), their level of organisation and adaptation can bring down entire worlds within months or years. Rather than having a Hive Fleet invade, one story could accurately represent this with a tale focusing upon the infiltrators bringing down a world from within. An in depth campaign covering everything from the Genestealers' arrival upon the world to their uprising crippling it for the incoming Hive Fleet.
This could be represented just as well on the tabletop as in the fluff. While the tyranids do benefit from certain infiltration methods such as outflanking or the trigon's burrowing capabilities, there is little to represent real long term infiltration. The closest you can really get is using an Imperial guard force and passing them off as cultists. Perhaps members of the enemy force the tyranids are opposing run the risk of sabotaging their efforts or killing key figures a-la Commissars with Catachans.
There's plenty to be done with this aspect of the tyranid race, perhaps it's time a codex placed some serious focus upon it once more.
2 - Greater Genetic Variation
This has always seemed like an odd issue with the tyranids: Their overall goal. The entire process of the Hive Fleets to invade new worlds, consume planets and gather new biomass is one which is only occasionally directly addressed. Often it's only used to excuse the presence of certain new creatures within the army, such as tyrant guards being based upon astartes DNA, but there is a great deal more story potential to the process than just this.
Consider for a moment just how much each Hive Fleet would diverge from one another genetically but entering the galaxy in another location. Between Kraken and Leviathan alone, there are countless Splinter Fleets emerging in vastly different sectors of the galaxy meaning certain ones are encountering entirely different races from one another. Some are encountering heavy resistance from defenders and direct combatants, others only through freakish elements of worlds they invade. Some attack worlds which have humanoid inhabitants, others might encounter races based upon silicon or completely different lifeforms. While many are certainly encountering resistance from Imperial cordons to hostile lifeforms, they are all supposedly adapting and evolving into different forms and reacting in different ways. Despite this however, no tyranid force is ever written to truly diverge from one another. They all have the same units, all have the same basic structure, weaknesses and tactics, and never seem to truly evolve beyond what they were before. These are supposed to be monsters whose super fast evolution is their greatest strength, but it seems no writer really knows how to handle it.
Let's say that a tyranid Splinter Fleet managed to take down an entire alien race, with entirely new genetic material to enhance its monsters and further its case. At best we would see one new unique unit going from what the books have covered, based upon that race's DNA. It wouldn't be distributed throughout the fleet or used to create widespread changes which would effect how they fought. For all humanity's dominance of the galaxy, there are still countless alien races which could provide a wealth of interesting possibilities for the army. The books also do not explore what possibilities might come of the genetic deviations or differences within race sub-species. Sticking with the example given above, we've already seen what little impact space marine DNA would have to the tyranids. What about gene-seed bearing psychic phenomena or flaws? Would a Hive Fleet which consumed Blood Angel gene-seed become unstable, affected by the Black Rage or would it create some new aspect unseen until then? If it was rejected, what impact would what have on the future of the fleet? What about creatures corrupted by Chaos?
The next book could do with making more of an effort to just explore the impact of consuming the DNA of others. As such a core element of the army's personality, it would be interesting to see it having much more significant impact and allowing for some degree of change.
1 - The Death of Worlds
One of the things made relentlessly clear about the tyranids is one very clear fact: They will keep coming. When they find a world, they will deploy their forces against it and proceed to either consume all life on it or be killed in the effort. This is a fact made clear multiple times, yet the point of the massive number of worlds they consume never really hits home. The last codex just didn't focus upon it in the right way and convey the anarchy their actions would surely cause.
Think about it for a minute. Going from most tyranid lore, there should be entire sub-sectors rendered completely barren by their attacks yet you'd never really get that impression going from some lore. Now, there have been efforts to display the damage the space bug swarm can cause by taking out vital facilities such as major Forge Worlds but these are often presented as individual situations. The same went for the campaigns in the previous book, even when the battles were massive they only seemed to focus upon a handful of worlds being invaded and never emphasised upon the long term consequences of entire systems being consumed.
The Imperium is based upon worlds sustaining one another through constant shipments, cargo lanes and the like. If a Splinter Fleet managed to take out a manifactorum, major mustering grounds or agri-world then it would have definite impact upon others. There would be machinery shortfalls, armies would lose new recruits and even rationing. It would potentially make regions unstable, open for conquest, and this is without getting to the real horror behind the point.
In a follow-up to an event from the last codex, Codex: Tau noted that an entire section of their empire had been reduced to lifeless rock following a tyranid invasion. It served as a monument to the conflict and truly emphasised what the hive fleets were capable of. There should be far more instances like that within the Imperium, with ships delayed by the Warp or orders arriving at planets and learning to their horror what has befallen them. Seeing, rather than the crew's home and a lush paradise world, a disintegrating husk of a planet. It's the other side of the coin from before, emphaising upon the threat they pose as infiltrators. This would help to better emphasis what their swarms were capable of beyond describing major battles, and what failure to stop them will bring.
So those are the top five changes the next Codex: Tyranids needs. They're certainly not all of the changes and improvements the book requires, but they are the most pressing issues. Whether or not you agree is up to you and I imagine that many people think otherwise. Please feel free to leave your own thoughts below and outline what you would have put as major necessary changes instead.