Can't find it specifically asked so...
In regards to this:http://www.alderac.com/forum/viewtopic.php?f=59&t=78272
Can Daigotsu Gahseng react to cards being discarded from focus pools?
Thanks
Daigotsu Gahseng and Focus pool
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.
Can Daigotsu Gahseng react to cards being discarded from focus pools?
Yes. http://rules.l5r.com/CE_Effects#Source_of_effects: "Duels come from the effect that created their associated challenge, not the rulebook." By extension, the discard is also an effect of the action.
On: Daigotsu Gahseng
Correction: http://rules.l5r.com/CE_Effects#Source_of_effects: "If a card effect creates a procedure, effects written in the rulebook that are part of the procedure come from the rulebook. [Added 9 September 2009]
That was in there, which I overlooked because it was very generic and wasn't sure it applied in this case. So I've now added an example.
"Example: An action on a card creates a duel. Discards from the duel are considered to be rulebook effects, rather than action or card effect, because the procedure for resolving the duel is described in the rulebook."