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, 6 August 2009
This is a question on how exactly does Reinforce the gates work in Celestial Edition.
Player 1 attacks Province A with one unit, Player 2 defends at Province B with one unit. Player 1 (the attacker) decides to resolve the battle at province B first. Both players pass and the battle ends. Then the attacker decides to resolve the battle at province A. At that battle Player 2 (the defender) attempts to play Reinforce The Gates, to move the attacking unit to Province B. Is that legal? does the battlefield at Province B still exist, after the battle has resolved. Thanks in advance.
A player, 6 August 2009
This is a question on how exactly does Reinforce the gates work in Celestial Edition.
Please use the search function before asking new questions: you would have found "Reinforce The Gates and moving to resolved battles", which would have led you to several rulings that answer your question.
Player 1 attacks Province A with one unit, Player 2 defends at Province B with one unit. Player 1 (the attacker) decides to resolve the battle at province B first. Both players pass and the battle ends. Then the attacker decides to resolve the battle at province A. At that battle Player 2 (the defender) attempts to play Reinforce The Gates, to move the attacking unit to Province B. Is that legal?
Yes this is legal. The battlefield at Province B still exists after the battle there has resolved. Defending units do not move home when the battle ends (unless they are allied units), they remain at the current battlefield until battles have ended at all existing battlefields; at that time the attacking unit in Province B will move home bowed. For more information, see Battles, especially Final Steps.