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, 29 February 2012
If I perform an action that is a reaction can I target a card outside the battle with it?
As an example. I play Master the Elements which states: Reaction: Once per game, after this card enters play, target your Spell and pay Gold equal to its base Gold Cost: This card permanently copies the Spell's keywords, traits, and its base abilities that do not themselves copy abilities.
If I attach this to my shugenja at Battlefield A can I target a spell at Battlefield B or at my home to copy?
As another example with Waystation of the Path which states: Reaction: After another player's action targets your performing Henshin, target another of your Personalities: The Henshin is reborn. Transfer his attachments and tokens to the other Personality. The action's effects that would destroy your Henshin instead overlay him onto the Personality.
If Henshin A dies at Battlefield A can I react to overlay him with a Personality at Battlefield B or on a Personality at my home?
Jon Palmer (rules official), 29 February 2012
If I perform an action that is a reaction can I target a card outside the battle with it?
As an example. I play Master the Elements which states: Reaction: Once per game, after this card enters play, target your Spell and pay Gold equal to its base Gold Cost: This card permanently copies the Spell's keywords, traits, and its base abilities that do not themselves copy abilities.
If I attach this to my shugenja at Battlefield A can I target a spell at Battlefield B or at my home to copy?
As another example with Waystation of the Path which states: Reaction: After another player's action targets your performing Henshin, target another of your Personalities: The Henshin is reborn. Transfer his attachments and tokens to the other Personality. The action's effects that would destroy your Henshin instead overlay him onto the Personality.
If Henshin A dies at Battlefield A can I react to overlay him with a Personality at Battlefield B or on a Personality at my home?
Reaction targeting is not covered by the Rules of Presence and Location, so in both of these instances, you may target a card not at the current battlefield.