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.
At the current battlefield, I control two Gate Guardsman. My opponent takes a Battle Action. I react using Gate Guardsman's Reaction and take an additional battle action.
Can I react with the other Gate Guardsman and take another battle action or has the reaction trigger passed when I took the additional action granted by the first reaction.
Gate Guardsman: Reaction: After another player resolves a Battle Action, if this unit is at the current battlefield: Take an additional Battle action
At the current battlefield, I control two Gate Guardsman. My opponent takes a Battle Action. I react using Gate Guardsman's Reaction and take an additional battle action. Can I react with the other Gate Guardsman and take another battle action or has the reaction trigger passed when I took the additional action granted by the first reaction.
Reaction triggers don't "expire" on their own; players must deliberately pass. Comprehensive Rules, Timing: "Starting with the active player, each player in turn order has the option to take a Reaction to the trigger or pass. When all players pass consecutively, no more Reactions to that occurrence of the trigger may be taken."