The 5th edition Tyranid codex has often been condemned as uncompetitive. As a long-time Nid player, I’d just like to say, yes, yes, it is. But the position is far from hopeless.
The internet is full of codex-wide reviews and plaintive cries of “I want a fluffy assault-focused horde”. I’ll be doing something a little different here. I believe that a tournament-focused Tyranids list is actually rather fluffy. It can rapidly produce a mass of bodies, on par with the Ork horde and its uniformity actually adds to the menace in a way that a fluffier list composed of a hodge-podge of Nid units does not. It’s core tactic is to use the mass of bodies available to gum up the enemy’s lines and hope that something cracks. What could be fluffier?
The Tyranid playstyle is rather different to the standard 40k style. Rather than focusing on assigning firepower to targets, it revolves around attrition, sacrifice and force preservation. The most common decision is not what target to attack but rather what target to block. Individual units are not particularly resilent but the overall force can be.
There are a limited selection of worthwhile units in the Tyranid codex. Some are first rate units in a third rate codex, others are inherently poor but used out of necessity.
The First Rates
These are the beating heart of a Tyranid force and act as a windvane. Generally, the number of Tervigons left in the field is a strong indicator of the condition of your army. The spawning mechanic and ability to buff gaunt units all make for a potent force multiplier.
Their ability to provide Feel No Pain saves singlehandedly grant the units around them a degree of resilence otherwise lacking.
Frankly, these would be a solid unit in any codex. High toughness, accurate, a great gun and a good, if situational special rule. The range is a little short, but as the only source of decent anti-mech firepower, these become critical to your success.
This is something of a… lie. They are a first rate unit but only when spawned for free. They provide the bodies to gum up the enemy warmachine.
The Second Rates
Despite their many many failings, amongst them, paper armour and no way of mitigating the effects of cover in assaults; they can, when assisted by Tervigons and moving through cover, advance through fire and really cause difficulties for anyone without major anti-infantry firepower or flamers.
The only decent heavy AT gun you have. It’s accuracy is woeful but it’s happy to duel at range due to the fact that it boasts a 2+ save. As it’s a stand off unit, it can avoid the combat deathstars which chop through your MCs. And as a member of that fraternity, it’ll keep hitting at full power until its very last wound.
The Zoanthropes attracted a great deal of attention in the early days of the codex. They have one of the best anti-tank options in the game. But once brought onto the field, it soon falls apart. It’s range is poor but that is not an insurmountable problem. However, it does require a psychic test to activate and its short range effectively forces it into range of the psychic defences which shut it down.
Very expensive, grants a variety of buffs. Actually quite useful. It directly competes with your Hive Guard though and falls over dead at the first sign of danger. Another false dawn. If it weren’t for the average toughness, this could have had some potential.
This suffers from the bane of almost all the Tyranid monsterous creatures. Toughness 6 and a 3+ save protects you from nothing. There are very few heavy weapons that will not wound you on a 2+ and also punch right through your armour. When your intended role forces you to move into range of such weapons, your life is short and rather pointless.
Honestly, I could break them down unit by unit but in every case they fall short. They are either less suited to a role than one of the units above or when used in their intended role prove fatally flawed on the battlefield.
The main issue you face is the abundance of extremely sub-optimal match-ups. There are those that deny it but the codex simply cannot handle certain builds. Most of the newer codexes can, all other things being equal, swat you like the bugs you are. The staple of the Dark Eldar, the Venom skimmer, is your death. Barring ludicrous luck, you simply cannot defeat a force with more than six. They can simply gun down your shooting units and even your best melee units cannot drag them from the skies in any reasonable time. The Space Wolves have the benefits of many missile launchers which can hack away at support and synapse with ease. This is coupled with the psychic power, Jaws of the World Wolf, which really punishes the poor initative of your few decent units. The Grey Knights can also prove very very dangerous. The psychic power, Cleansing Flame, prevents you from using your numbers to win combats. And the army-wide force weapons neutralises your monsterous creatures. Hammerhand and psybolt ammunition works to counter your high toughness also.
In the special cases mentioned above, you play cautiously, preserve as much as possible and hope for runs of terrible luck on the part of the enemy. But outside of those, your chances are good against a wide range of lists. You the tools to go toe to toe with most codexes.
Onto the happy news, your overall strategy is actually quite interesting. In normal match-ups, you simply apply pressure to your opponent and exploit any errors made. The sheer mass of a Tyranid force can be intimidating. The pressure inflicted by your board control makes the opponent react to multiple threats and forces those errors.
The tactic is universally applicable to all armies but the concept of screening is utterly critical to a Tyranid force. This applies both on the squad and army level. Your backfield assets are vulnerable to any decent assault force and must be screened. Your counter-charging units must be screened until they are thrown into the fray. On the wider battlefield, you have the potential to clog large sections of the board. You can also use bait units in a manner few codexes can. When it comes to shaping the battlespace, the Tyranids excel unless they run out of bodies to throw into your path.
The ability to threaten multiple objectives simultaneously is critical as the Tyranids are quite slow. Your axis of attack can be clearly identified as soon as you start plodding in a particular direction. This means that you must commit your forces correctly at deployment, there will be no real chance to recover.
Overall, the codex retains an non-standard playstyle which has its appeal. A well-designed list has a mass to it which can let you bully through smaller forces. The ability to weather two turns of shooting and come out with a larger force is also deeply amusing, when it happens. Throwing unit after unit of termagaunts into Terminator squads and grinding them down through attrition is extremely satisfying. In essence, if you think you’d like being an Imperial Guard Lord Commander, you’d probably enjoy playing Tyranids.