A unit that contains at least one model with this special rule automatically passes Fear and Regroup tests. When it Regroups, the unit does not make the 3" Regroup move, but can instead move, shoot (or Run) and declare charges normally in that turn. Furthermore, if a unit containing one or more models with this special rule is caught by a Sweeping Advance, they are not destroyed, but remain locked in combat instead.
A full strength, ten-man unit with this special rule can break down into two five-man units, called combat squads, considered to be two five-man squads of the same type. For example, a ten-man Tactical Squad can split into two five-man Tactical Squads using the Combat Squads special rule. You must decide which units are splitting into combat squads, and which models go into each combat squad, immediately before determining your Warlord Traits. A unit split into combat squads therefore is now two separate units for all game purposes, including calculating the total number of units in the army and determining the number of units you can place in reserve. Then proceed with deployment as normal. In an exception to the normal rules, two combat squads split from the same unit can embark in the same transport vehicle, providing its Transport Capacity allows. Once you have decided whether or not to split a unit into combat squads, it must remain that way for the entire battle. It cannot split up or join back together later on in the battle, nor can you use a redeployment to split up a unit or join it back together. Note that Bike Squads count as being at full strength when they have eight Space Marine Bikers and one Attack Bike. If split into combat squads, one combat squad will have five Bikers, the other will have three and the Attack Bike.
When choosing an army, all models in the same Detachment or Formation must be drawn from the same Chapter. If a unit's datasheet contains a Chapter in brackets after the Chapter Tactics special rule - for example, "Chapter Tactics (Ultramarines)" - the unit must always be drawn from this Chapter, and therefore cannot be included in a Detachment or Formation with any units that are drawn from other Chapters. All models drawn from a given Chapter benefit from that Chapter's Special Rule. If a unit contains models drawn from two different Chapters, it counts as from neither Chapter, and thus benefits from neither Chapter Tactic.
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.
After both sides have deployed (including Infiltrators), but before the first player begins his first turn, a unit containing at least one model with this special rule can choose to redeploy. If the unit is Infantry, Artillery, a Walker or a Monstrous Creature, each model can redeploy anywhere entirely within 6" of its current position. If it is any other unit type, each model can instead redeploy anywhere entirely within 12" of its current position. During this redeployment, Scouts can move outside the owning player's deployment zone, but must remain more than 12" away from any enemy unit. A unit that makes a Scout redeployment cannot charge in the first game turn. A unit cannot embark or disembark as part of a Scout redeployment. If both sides have Scouts, roll-off; the winner decides who redeploys first. Then alternate redeploying Scout units. If a unit with this special rule is deployed inside a Dedicated Transport, it confers the Scout special rule to the Transport (though a disembarkation cannot be performed as part of the redeployment). Note that a Transport with this special rule does not lose it if a unit without this special rule is embarked upon it. Having Scout also confers the Outflank special rule to units of Scouts 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.
