Purestrain Genestealers have a 5+ invulverable save.
Only a Patriarch can join this unit. Whilst a Patriarch is joined to this unit, the Purestrain Genestealers gain the Furious Charge special rule.
Units with this special rule that Infiltrate, or that arrive from Reserve or Ongoing Reserve, can chose to roll on the Cult Ambush table instead of deploying or arriving from Reserves normally. Unless otherwise specified, ambushing units move onto the table as described for other Reserves and cannot move any further during the movement phase. Units cannot use the cult ambush special rule whilst they are embarked inside a vehicle.
Instead of moving in the movement phase, any unit with this special rule that is not within 6" of any enemy models, can be removed from the battlefield and placed into Ongoing Reserve. A unit cannot Return to the Shadows in the same turn it arrives from Reserves or Ongoing Reserves, and cannot do so whilst embarked in a vehicle.
A unit composed entirely of models with this special rule can re-roll one or more of the dice when determining Run moves and charge ranges (such as a single D6 from a charge range roll, for example).
Units that contain at least one model with this special rule are deployed last, after all other units (friend and foe) have been deployed. If both sides have Infiltrators, the players roll-off and the winner decides who goes first, then alternate deploying these units. Infiltrators can be set up anywhere on the table that is more than 12" from any enemy unit, as long as no deployed enemy unit can draw line of sight to them. This includes in a building, as long as the building is more than 12" from any enemy unit. Alternatively, they can be set up anywhere on the table more than 18" from any enemy unit, even in plain sight. If a unit with Infiltrate deploys inside a Dedicated Transport, they may Infiltrate along with their Transport. A unit that deploys using these rules cannot charge in their first turn. Having Infiltrate also confers the Outflank special rule to units of Infiltrators that are kept as Reserves. If a unit has both the Infiltrate and Scout special rule, that unit can deploy as per the Infiltrate special rule and then redeploy as per the Scout special rule.
A unit that contains at least one model with this special rule rolls an extra D6 when rolling to move through difficult terrain and is not slowed by charging through difficult terrain. In most circumstances, this will mean that, when moving, the unit rolls 3D6 and picks the highest roll. Furthermore, a model with the Move Through Cover special rule automatically passes Dangerous Terrain tests.
A unit that contains at least one model with this special rule counts its cover saves as being 1 point better than normal. Note that this means that a model with the Stealth special rule always has a cover save of at least 6+, even if it is in the open. This rule is often presented as Stealth (X) where X indicates a specific type of terrain, such as Stealth (Woods) or Stealth (Ruins). If this is the case, the unit only gains the benefit whilst it is in terrain of the specified type. Cover save bonuses from the Shrouded and Stealth special rules are cumulative (to amaximum of a 2+ cover save).
