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, 3 November 2010
If I attack my Crab opponent's province, he has Hiruma Gondo in play, he doesn't assign any defenders, and I destroy the province in resolution, does Gondo destroy himself?
I found in the rules that a player wins a battle if unopposed, but does the opposite count? Or reworded, can you lose a battle if you have no units?
Hiruma Gondo Crab Clan • Samurai • Berserker • Hero After a battle's resolution, if you lost the battle and its resolution destroyed any of your units or provinces: Destroy Gondo.
A player, 3 November 2010
If I attack my Crab opponent's province, he has Hiruma Gondo in play, he doesn't assign any defenders, and I destroy the province in resolution, does Gondo destroy himself?
Yes, his own trait destroys him.
I found in the rules that a player wins a battle if unopposed, but does the opposite count? Or reworded, can you lose a battle if you have no units?
Although the comprehensive rules do not define the loser of a battle, normal English applies. If a battle is won by a player, the enemy leader loses that battle. In your example, you won the battle so your Crab opponent lost it.