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, 28 July 2008
Right to Rule, an event from the Spirit Wars set, states that "Each player destroys his or her rightmost Province unless he or she renounces the ability to win by any means other than an Enlightenment, Honor, or Military Victory."
If I recall correctly, at the time Right to Rule was printed, a "dishonor" victory was actually a type of military victory because a Military Victory was simply when you were the only player left.
Two questions:
1) Under Samurai rules, Dishonor is its own, distinct, category of victory. If you renounce in order to save your province when Right to Rule resolves, does this preclude you from achieving a Dishonor Victory? I checked, but didn't see anything in the Legacy rules that grandfathered the meaning of the term "Military Victory" for older cards.
2) If Right to Rule can preclude a player from achieving a Dishonor Victory . . . if you renounce your ability to win via a Dishonor Victory, does this also prevent prevent your opponent (or your last opponent, in multi-player) from suffering a dishonor loss? Or does it effectively create a double-loss (because your opponent has lost, but you cannot win)?
Brook Cunningham (rules official), 29 July 2008
...if you renounce your ability to win via a Dishonor Victory, does this also prevent prevent your opponent (or your last opponent, in multi-player) from suffering a dishonor loss?
Right to Rule in no way affects your opponent's criteria for losing. He loses by Dishonor before you are considered to have "won" by it, so your inability won't retroactively save him. Consider a multiplayer game; a number of players might lose by Dishonor without you ever winning by it.
...does it effectively create a double-loss (because your opponent has lost, but you cannot win)?
The concept of the double-loss only exists in the Tournament and Event Floor Rules and can only be caused by such.
As far as the rules of the game (and logic) that govern card effects are concerned:
If every other player in your game has lost, then you win.
As an aside: If you happen to playing some homebrewed tournament format, wherein each player's manner of Victory is recorded for some purpose, feel free to withhold a tick in the "Dishonor Victory" column from a player who won under these circumstances.