Editing Warhammer 40,000/8th Edition Tactics/Tyranids (section)

==Special Rules==
No matter what edition of the game, Tyranids have traditionally been defined by three special rules: '''Synapse''', '''Instinctive Behaviour''' and '''Shadow in the Warp'''. For some reason, designers have tended to tinker with these every time a new codex comes out, much to the endless aggravation and rage of countless Tyranid players. 8th edition seems to be no exception, with the rules being changed not once but twice. Once for the index, and again for the codex. '''When in doubt, rely on the codex version until the rules inevitably get changed once again'''.

*'''Instinctive Behaviour''': If a {{W40kKeyword|<HIVE FLEET>}} unit with this ability is more than 24" away from a friendly {{W40kKeyword|<HIVE FLEET>}} '''Synapse''' unit, then it suffers a penalty to shooting and charging unless the target is the nearest visible and viable unit. If shooting, the penalty is a -1 to hit, and if charging, the unit suffers a -2 penalty to its charge move. An ''even less'' restrictive Instinctive Behaviour, so we're better off than ever before.
**Formerly, instinctive behaviour limited a unit to only being able to shoot and charge the nearest visible enemy unit. The current is a much welcome quality of life improvement, as you will no longer need '''Synapse''' units to babysit your Pyrovores, Biovores, or anything else not particularly interested in successfully rolling to hit with shooting or making a charge roll, such as a Tyrannofex shooting its Acid Spray. At the same time, it gives your bigger creatures that wouldn't benefit from Morale immunity in the first place more room to wander off without being penalised for it. 
**Worth noting that this just affects shooting and charging targets. You unit can still act normally regarding moving, advancing, and retreating.
**With the recent changes, choosing the correct '''Synapse''' units for your army has become far more forgiving. However, it is still a good idea to try and pair units up based on their roles. Keep fast units with fast units (Broodlords and Genestealers, for instance) and slower ones with your second wave or artillery units.
*'''Shadow in the Warp''': Enemy {{W40kKeyword|PSYKERS}} must subtract 1 from any Psychic test they make if they are within 18" of any units with this ability. {{W40kKeyword|TYRANID}} {{W40kKeyword|PSYKERS}} are not affected.
**Was formerly listed at 8" in the index but has been changed for the codex. The addition of a whopping 10" to this rule is understandably quite a big deal now that its range is long enough to mess with Smite spammers.
**Frankly, a rule often forgotten in the 7th Edition days due to how infrequently it came in use. Now with the increased potency and ease of manifesting powers, plus the new mechanism of denying a power cast within 24" of one of your psykers, putting them at a -1 disadvantage makes this an ability worth having. 
**Reminder: {{W40kKeyword|GENESTEALER CULT}} {{W40kKeyword|PSYKERS}} also count as {{W40kKeyword|TYRANID}} {{W40kKeyword|PSYKERS}}. On the one hand, you can add {{W40kKeyword|GENESTEALER CULT}} units to your army without having to play careful positioning games, but on the other hand, if you're playing against them, '''Shadow in the Warp''' is worthless.
*'''Synapse''': {{W40kKeyword|<HIVE FLEET>}} units automatically pass Morale tests if they are within 12" of any friendly {{W40kKeyword|<HIVE FLEET>}} units with this ability.
**Was formerly listed at 8" in the index, but has been changed for the codex.
**The removal of templates and this rule makes Tyranids one of the best armies to run large blobs of units with.
**Automatically passing Morale tests is a big deal in 8E. Much of the new meta is about killing the enemy army via morale attrition, and the Tyranids raise a middle appendage to such mechanics. While it's less helpful to Carnifexes and other monsters which deploy as individuals (and therefore were already unaffected by morale), Gaunts and other units that work best with a lot of models have more to lose from a bad morale roll and will benefit the most from Morale immunity.
**Makes Imperial Guard players really jealous since their Commissars got nerfed, [[That guy|so be sure to rub it in their face]].
*'''Extensions of the Hive Mind''': Objective Secured, Tyranid edition.
===Hive Fleet Adaptations===
Another Codex brings another set of Chapter Tactics-equivalents, representing the main 3 Hive Fleets in the fluff (Behemoth, Kraken, and Leviathan) as well as 4 others that range from the obscure to the entirely new. Unlike other factions with Chapter Tactics-equivalents, your choice of Hive Fleet does '''not''' limit which special characters you can take. Splinter fleets take the Adaptation of their progenitor, while Hive Fleets not otherwise listed can pick and choose whichever Adaptation they like.
*'''{{W40Kkeyword|BEHEMOTH}} - Hyper-Aggression''': Re-roll failed charges; gives you 8" charges 65.97% of the time and 9" charges 47.84% of the time. Consider taking adrenal glands on deepstriking Trygons, Gargoyles, Hive Tyrants, and Hormagaunts.
*'''{{W40Kkeyword|GORGON}} - Adaptive Toxins''': Re-roll wound rolls of 1 in the Fight phase. Great on anything really, but bugs with Scything Talons (big and small) and Toxin Sacs are real nice.
*'''{{W40Kkeyword|HYDRA}} - Swarming Instincts''': Re-roll failed hits in the Fight phase against units that you outnumber. Your Hormagaunt and Gargoyle swarms will thank you for taking this, because why '''''wouldn't''''' they outnumber their targets? 
** Unfortunately this is completely useless on any of your big bugs. Furthermore, later in the game after your horde has been thinned out it can more or less render this adaptation meaningless. Luckily, their Stratagem can address the latter issue.
*'''{{W40Kkeyword|JORMUNGANDR}} - Tunnel Networks''': Non-{{W40Kkeyword|FLY}} units always count as being in cover for shooting attacks, but advancing or charging makes this drop until your next Movement phase. Requires a slight drop in mobility to make it work, but it compensates by offering better defence in return. Consider using Trygons alongside Jormagundr's Stratagem to make up for the lost mobility. If you want to be [[That guy]] model your army as a bunch of shark fins sticking out of dirt.
*'''{{W40Kkeyword|KRAKEN}} - Questing Tendrils''': Can charge after Falling Back, and rolls 3d6 keep the highest for Advance rolls (average: 4.96", up from the baseline of 3.5"). The correct choice if you go Genestealer heavy, since between this and the Stratagems they can rocket to the opposite side of the board on the first turn. Also good on Carnifexes since you can always trigger Living Battering Ram on your turn. Also very useful for controlling the board, whether it be objective-grabbing or preventing Deep Strikes from fucking your game up. Long range/shooty armies will shed salty biomass when half your army is already within kissing distance by turn 2, eager to give loving hugs with their talons and maws.
*'''{{W40Kkeyword|KRONOS}} - Bio-Barrage''': Re-roll hit rolls of 1 in the Shooting phase if you didn't move - basically the Cadian Doctrine, but without the ability to use an order to make it apply to melee instead of ranged. Much needed for shooty Nids given their average BS, and the requirement to be stationary doesn't matter as much for Tyrannofexes and Exocrines since you'll probably keep them still anyway.
** If you want to play Dakkefexes, this isn't a good Adaptation for them considering their main strength is mobility
*'''{{W40Kkeyword|LEVIATHAN}} - Synaptic Imperative''': 6++ FNP within 6" of a Synapse creature, provided that the unit in question has not been affected by Catalyst (which overrides this). One more backup save with the potential to negate mortal wounds never hurt anyone, and it's less specialised than the other Adaptations so it allows a greater degree of flexibility in your army.
**Naturally that goes for the synapse creature itself as well, since - of course - it is within 6" of itself. Duh.
====Custom Adaptations====
Like several armies before them, the Psychic Awakening expansion will offer the Tyranids the ability to create bespoke Hive Fleet Adaptations by combining any two of the rules listed below.
Keep in mind that unlike other races with similar custom traits, tyranids don't get to choose a main strain to be a successor of (though the FAQ may end up saying otherwise). So while choosing your custom adaptations let's you tailor 
your hive fleet to fit your army, you don't get access to hive fleet specific stratagems or psi powers.
*'''Adaptive Exoskeleton''': 6++ for gaunts, gants, and gargs.
*'''Bestial Nature''': +2 attacks to models with a damage table and on the last row.
*'''Bio-metallic Cysts''': Improves AP of all Scything Talon weapons by one. ('''FAQ'd.''' Now only affects basic scything talons. No love for monsters.)
*'''Bio-sphere Consumption''': 6+ ranged FnP for Monsters in the first turn, or who have not moved in the movement phase.
*'''Cranial Channelling''': Once per turn, when a psychic test is taken for a model with this adaptation, you may re-roll the result. ('''FAQ''' clarifies that it's once per turn for a single psyker unit in the army. Utter Bullshit.)
*'''Feeding Frenzy''': 6" pile-in.
*'''Horror From Beyond''': -1 LD to enemy units within 3" of Monsters. When will GW learn that low range -LD auras don't work.
*'''Hypermetabolic Acceleration''': Reroll Advance rolls.
*'''Membranous Mobility''': -1 to hit against your units with fly in melee. Stacks with blinding poison from gargoyles.
*'''Metamorphic Regrowth''': Regain 1 lost wound at the beginning of each turn. Great adaptation for monster heavy armies. Makes Old One Eye virtually immortal, especially if he's your warlord.
*'''Morphic Sinews''': '''MONSTER''' Models do not suffer the penalty for moving and shooting heavy weapons, or advancing and shooting assault weapons. Surprisingly good, as it makes up for lack of range.
*'''Pack Hunters''': -1 AP to melee weapons when you fight units with fewer models.
*'''Prey Sight''' +1 to hit rolls for Monsters that charged, are charged or heroically intervened. This is a lovely little adaptation for Nidzilla armies. Trygons hitting on 2s with a reroll. Same for Hierodules. Carnifexes hitting on 2s with their crushing claws as long as Old One Eye is along for the ride. Haruspexes being borderline useful.
*'''Senses of the Outer Dark''': FnP 4+ against enemy Overwatch. Cuts 50% of all overwatch damage taken. Fuck. The. Tau. Thats pretty damn good, though useless when you charge a model that is built around melee to begin with (CC nators, most Orks, etc).
*'''Shrewd Predators''': Consolidation moves can be made wherever you want as long as there aren't enemy models within 3.
*'''Sporemist Spines''': can advance when falling back.
*'''Synaptic Augmentation''': If a unit is within 6" of a Synapse creature, it may re-roll 1 hit roll when chosen to shoot or fight. Works best on MSU and monster heavy lists.