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.
What's the ruling now for reactions? can you perform a reaction even when you have no units in current battlefield?
Hamstrung: Reaction: Before the resolution of an action: Choose a Personality. Negate his movement into attacking armies from the action.
Unwavering Assult : Battle: Target a Samurai Personality in your home: Straighten his unit. Move him to the current battlefield.
What's the ruling now for reactions? can you perform a reaction even when you have no units in current battlefield?
Hamstrung: Reaction: Before the resolution of an action: Choose a Personality. Negate his movement into attacking armies from the action.
Unwavering Assult : Battle: Target a Samurai Personality in your home: Straighten his unit. Move him to the current battlefield.
Reactions have never needed presence unless card text explicitly requires it ("target one of your units at the current battlefield, etc).
Reactions are not, nor have they ever been under the Rules of Presence and Location.