Editing Warhammer 40,000/9th Edition Tactics/Movement 101 (section)

===Special: Reinforcement (AKA Deep Striking)===
A unit may have the ability to be set up on the battlefield during the game.  Regardless of the rule the unit in question is using, unless otherwise noted, it ''cannot'' move (and hence cannot advance) for the rest of the turn. They also count as having moved for all rules purposes, such as shooting Heavy weapons.  Any unit in the army that ends the battle without ever having Reinforced in counts as destroyed for all rules purposes.
*Note:  This means Psychic powers allowing movement used on a unit which Reinforced in this turn do not actually allow the movement unless they explicitly state they do so.
*Following the first Big FAQ, Deep Striking has gotten a significant modification. While it was originally possible to deep strike units into the opponent's deployment zone on the first turn (allowing the deep strikers to wipe out enemy units before they even got a chance to move), the new Deep Strike rules explicitly state that any unit that arrives via Deep Striking on the first turn '''can only be set up in the user's deployment zone'''. This limits its original game-breaking offensive power to the second turn or later, but still allows for [[Indrick Boreale|defensive deep strikes]] for discouraging enemy offensive pushes. 
**The above does not affect abilities that act like Infiltrate did in 7e, such as the Raven Guard's ''Strike from the Shadows'' Stratagem or the Genestealer Cults' Cult Ambush ability. 
*The second Big FAQ modified this again. Now you can't deep strike on the first turn '''at all'''. It is expected that this will produce similar results to the original FAQ modifications, albeit tweaked so neither attackers nor defenders can take advantage of turn one deep strikes. The sole exception is the Space Marines' Drop Pod, which is unaffected by this change. 
**Accordingly, abilities that act like Infiltrate now grant a turn 0 move for a single unit. The Genestealer Cult codex got around this by significantly modifying the Cult Ambush rule into a unique deployment variant in addition to the option to set up units in deep strike reserve. This option allows a unit with the Cult Ambush rule to be set up on the board, but conceals the unit's identity until either the start of the user's movement phase or the end of the enemy's movement phase, depending on who got to go first. 
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