A topic from AEG's L5R CCG Rules forum, copied for Oracle of the Void from a copy of the forum saved in October 2015, so pages it didn't save are missing. Players' names are left out; the rules officials are named. Rulings are as they stood on these dates; later rulings, the rulebooks and the Rules Archive may differ.
A player, 30 August 2011
Deployed Reinforcements - Terrain Battle: Before this battle's resolution, if you control any units at the current battlefield, you may target a unit in your home and move it to the current battlefield. Straighten it if it moved.
Pinned Down - Reaction: Before the resolution of another player's action, target your Kensai at the current battlefield and bow one of his Weapons: Choose an enemy Personality, and negate either his straightening or his movement from that action.
I am attacking. My plan is to use Deployed Reinforcements to move Akuma no Oni to a battlefield. Would my opponent be able to use Pinned Down to stop this? When would he play it? When would he target Akuma no Oni? If he is required to target Akuma no Oni before it comes time for me to select a unit to move, would I be able to select a different unit instead? If I destroyed the bowed weapon or the Kensai before the time for movement would that cancel the Pinned Down? If the Deployed Reinforcements Terrain is destroyed/removed before the battle's resolution, does that cancel movement? Finally, what other things could prevent the movement from the Deployed Reinforcements?
Thank you.
Brook Cunningham (rules official), 30 August 2011
Would my opponent be able to use Pinned Down to stop this?
Yes.
When would he play it?
Right after the Terrain enters play, which is before it resolves, per Pinned Down's text. (And from here: "the Strategy card enters play at the current battlefield as a rulebook effect, before the Terrain action resolves.")
When would he target Akuma no Oni?
During the resolution of Pinned Down's action, well before you select your Personality for your Terrain's delayed effect.
EDIT: Also, as a clarification, he is not targeting Akuma but rather "choosing" him; slightly different.
If he is required to target Akuma no Oni before it comes time for me to select a unit to move, would I be able to select a different unit instead?
Yes.
If I destroyed the bowed weapon or the Kensai before the time for movement would that cancel the Pinned Down?
No. The cost has already been paid, and the effects already applied.
If the Deployed Reinforcements Terrain is destroyed/removed before the battle's resolution, does that cancel movement?
Yes. (Again, from here: "If a Terrain leaves play before a battle’s Final Steps, its ongoing effects end, and its delayed effects will no longer be applied.")
Finally, what other things could prevent the movement from the Deployed Reinforcements?
It's a little beyond the scope of the Rules Team to provide an exhaustive list of such things, sorry.
A player, 30 August 2011
About this.
I'm aware you can react regardless of place (not in this case, but that's the card making an exception), but can I target another Player's Personality at home if my Kensai is at the current battlefield?
Brook Cunningham (rules official), 30 August 2011
About this.
I'm aware you can react regardless of place (not in this case, but that's the card making an exception), but can I target another Player's Personality at home if my Kensai is at the current battlefield?
Reactions are not subject to the Rules of Presence or Location, so there are no restrictions upon what they can target during the Combat Segment.
However, I added a clarification above and will reiterate here: Pinned Down does NOT even actually "target" the Personality whose movement its player wishes to prevent.