TEXT: 1
  WARHAMMER 40,000 – CODEX: TYRANIDS
  WARHAMMER 40,000 
  CODEX: TYRANIDS
  Official Update Version 1.0
  Although we strive to ensure that our rules are perfect, 
  sometimes mistakes do creep in, or the intent of a rule 
  isn’t as clear as it might be. These documents collect 
  amendments to the rules and present our responses to 
  players’ frequently asked questions. As they’re updated 
  regularly, each has a version number; when changes 
  are made, the version number will be updated, and any 
  changes from the previous version will be highlighted 
  in magenta. Where a version number has a letter, 
  e.g. 1.1a, this means it has had a local update, only in 
  that language, to clarify a translation issue or other 
  minor correction.
  ERRATA
  Page 101 – Biovores, Spore Mine Launcher
  Change the first sentence of the second paragraph 
  to read:
  ‘Each time a spore mine launcher misses its target, set 
  up a single <Hive Fleet> Spore Mine model anywhere 
  within 6" of the target unit and more than 3" from any 
  enemy model (if the Spore Mine cannot be placed it 
  is destroyed).’
  Page 109 – Harpy, Spore Mine Cysts
  Change the first sentence of the second paragraph 
  to read:
  ‘Each time a Spore Mine misses its target, set up a single 
  <Hive Fleet> Spore Mine anywhere within 6" of the 
  target unit and more than 3" from any enemy model (if 
  the Spore Mine cannot be placed it is destroyed).’
  Page 110 – Sporocyst, Spawn Spore Mines
  Change the second sentence to read:
  ‘If it does so, add a new unit of 3 <Hive Fleet> Spore 
  Mines or 1 <Hive Fleet> Mucolid Spore to your army 
  and set it up on the battlefield so that it is wholly within 
  6" of the Sporocyst and more than 1" from the enemy 
  (any models that cannot be placed are destroyed).’
  Page 110 – Sporocyst, Spore Node
  Change the first sentence of the second paragraph 
  to read:
  ‘Each time a spore node attack misses its target, add 
  a new unit of 3 <Hive Fleet> Spore Mines or 1 <Hive 
  Fleet> Mucolid Spore to your army and set it up on the 
  battlefield so that it is wholly within 6" of the target unit 
  and more than 3" from any enemy model (any models 
  that cannot be placed are destroyed).’
  Page 116
  Change the first sentence to read:
  ‘In this section you’ll find rules for Battle-forged armies 
  that include Tyranids Detachments.’
  Add the following section before ‘Abilities’:
  ‘Tyranids Units
  In the rules described in this section we often refer to 
  ‘Tyranids units’. This is shorthand for any Tyranids 
  unit that also has the <Hive Fleet> keyword. A Tyranids 
  Detachment is therefore one which only includes units 
  with both the Tyranids and <Hive Fleet> keyword. 
  Note that although Genestealer Cults are devoted to 
  the Hive Mind and will willingly fight alongside their 
  xenos masters, they deviate significantly in terms of 
  organisation and tactics, not to mention physiology! 
  Genestealer Cults units therefore cannot make use of 
  any of the rules listed in this section (this includes the 
  Detachment abilities, Stratagems, bio-artefacts, psychic 
  powers, Warlord Traits and Tactical Objectives described 
  in this section), and instead have their own rules.’
  Page 117 – Jormungandr: Tunnel Networks
  Change the second sentence to read:
  ‘If the unit Advances or declares a charge, however, it 
  loses the benefit of this adaptation until the start of your 
  next Movement phase.’
  Pages 119 and 120 – Sporefield and Call the Brood
  Add the following sentence:
  ‘This unit must belong to the same Hive Fleet as another 
  unit from your army.’
  Page 119 – Pheromone Trail
  Add the following sentence:
  ‘You cannot use this Stratagem to affect a unit of 
  reinforcements being set up by the Genestealer’s 
  Infestation ability, or that are added to your army due to 
  a unit’s ability.’
  Page 120 – Hyper-toxicity
  Change the first sentence to read:
  ‘Use this Stratagem at the start of the Fight phase.’
  
  2
  WARHAMMER 40,000 – CODEX: TYRANIDS
  FAQs
  Q: When a unit is set up in a locale other than the battlefield, 
  can they change that locale (other than to be set up on the 
  battlefield)? For example, if a unit is set up ‘within the tunnels’ 
  as part of The Enemy Below, must they be set up on the 
  battlefield following that Stratagem, or can they be set up in 
  another fashion?
  A: They cannot change their locale. In the example, 
  they can only be set up on the battlefield following the 
  conditions of The Enemy Below.
  Q: When a unit is chosen to make a charge move and fails the 
  charge, do they still count as having charged? Specifically, can 
  a unit that has failed a charge move be chosen to pile in – and 
  potentially consolidate – towards the enemy?
  A: A unit only counts as having charged if they made a 
  charge move. If a charge fails, and no models make a 
  charge move, they do not count as having charged. As 
  such, they cannot be chosen to fight in the Fight phase 
  (and so cannot pile in or consolidate) unless an enemy 
  unit moves within 1" of them.
  Q: Can a unit ever Advance twice in a single phase?
  A: No.
  Q: If a unit has Advanced in a phase, and is given the 
  opportunity to move again in the same phase, what is their 
  Move characteristic?
  A: Their Move characteristic for the second move would 
  still be the value as modified from the Advance.
  For example, if a unit with a Move characteristic of 5" 
  Advances in a Movement phase, and the result of the 
  dice rolled for the Advance is 4, its Move characteristic 
  would be modified for that phase to 9". As such, if it was 
  given the opportunity to move again in that phase, its 
  Move characteristic would still be 9".
  Q: If a new unit is added to an army – for example as a result 
  of the Sporefield or Call the Brood Stratagems – is it part of 
  a Detachment?
  A: No.
  Q: Can a Broodlord use the Genestealers’ Infestation ability to 
  be set up during the battle near an infestation node?
  A: No.
  Q: If you use a Maleceptor’s Psychic Overload ability, can that 
  Maleceptor attempt to manifest any psychic powers in that 
  Psychic phase?
  A: No.
  Q: If a model has more than one pair of scything/monstrous 
  scything/massive scything talons, does it make 1 additional 
  attack with one of those pairs, or 1 additional attack with each 
  of those pairs?
  A: 1 additional attack with one of those pairs.
  Q: If a model has more than one ‘pair’ of boneswords, does 
  it make 1 additional attack with one of those pairs, or 1 
  additional attack with each of those pairs?
  A: 1 additional attack with one of those pairs.
  Q: Do Hive Fleet Jormungandr units gain the cover bonus twice 
  if they are in ruins?
  A: No.
  Q: Does the Psychic Barrage Stratagem prevent all three units 
  of Zoanthropes from attempting to manifest psychic powers 
  that turn?
  A: Yes.
  Q: If I use the Metabolic Overdrive Stratagem on a unit in the 
  Movement phase, and then Onslaught on the same unit in the 
  Psychic phase, can that unit charge?
  A: No.
  Q: Do you pay reinforcement points in matched play for Spore 
  Mines brought into the game using the Sporefield Stratagem?
  A: Yes.
  Q: If my opponent has units that are set up after both armies 
  have deployed, when do I use the Sporefield Stratagem – before 
  or after those units are set up? If before, how do you determine 
  who would place their units first?
  A: You use the Stratagem before any such units are set 
  up. If both players then have units with abilities that 
  allow them to be set up after both armies have deployed, 
  the players should roll off and the winner decides who 
  sets up their units first.
  Q: When using the Pheromone Trail Stratagem, can you bring 
  the Lictor onto the battlefield in the same turn as the unit that it 
  acts as a homing beacon for?
  A: Yes – simply bring the Lictor onto the battlefield 
  before the other unit.
  Q: Do you pay reinforcement points in matched play 
  for units brought back into the game using the Endless 
  Swarm Stratagem?
  A: Yes.
  Q: Can the Opportunistic Advance Stratagem be used when a 
  unit is affected by the Swarmlord’s Hive Commander ability, the 
  Overrun Stratagem, or the Mind Eater Warlord Trait?
  A: Yes in all cases. Please note the FAQ above regarding 
  moving multiple times in a single phase.
  Q: If a unit with adrenal glands is affected by the Opportunistic 
  Advance Stratagem, how is their movement for that 
  phase calculated?
  A: Adrenal glands don’t modify either the Movement 
  characteristic of a unit, or the dice rolled for an 
  Advancing unit. As such, you would use Opportunistic 
  Advance, roll the dice, double the result, add that to 
  the Movement characteristic, and then use the adrenal 
  glands to add 1" to the distance the unit can move.
  
  3
  WARHAMMER 40,000 – CODEX: TYRANIDS
  Q: Do the Scythes of Tyran allow you to re-roll hit rolls of 1?
  A: No.
  Q: My Behemoth Hive Tyrant, armed with toxin sacs and the 
  Reaper of Obliterax, has the Monstrous Hunger Warlord Trait. 
  If I were to roll a 6 to wound in the Fight phase, would the final 
  damage be (3 for the bonesword lash + 1 for toxin sacs + 1 for 
  the Warlord Trait) × 2 for the Reaper of Obliterax’s ability for 
  a total of 10, or 3 for the bonesword lash × 2 for the Reaper of 
  Obliterax’s ability + 1 for toxin sacs + 1 for the Warlord Trait 
  for a total of 8?
  A: You multiply the weapon damage for the Reaper of 
  Obliterax ability, and then add 2 for the combination of 
  Monstrous Hunger and toxin sacs for a total of 8.
  
SOURCE: textdata/thevault/Warhammer/40k/1st-8th Editions (Prior)/8th Edition (2017)/5) FAQs/2017 FAQs/40K_8th_ed_Update_Codex_Tyranids_Ver_1.0.pdf