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, 19 June 2008
Considering, for example, the scenario involving 2F Moshi Taya and 5F base Hida Bob with an Iron Tetsubo exchanging force with Determination taken as a reaction before Taya's Battle action was announced: Definitely, Taya will end up with 9F. Will Hida Bob end up with 2F or 9F?
Moshi Taya Battle: Exchange the Force of one of your target Naval Personalities with the Force of a target Personality opposing him.
Iron Tetsubo Negate all Force penalties on this Personality.
Determination Dark Virtue Reaction: Before you announce an action, target one of your Samurai: The action can not have its effects negated or have its targeting changed. After the action destroys any Personality, remove him from the game.
1. Moshi Taya is currently at 2F. Hida Bob is at 9F.
2. Iron Tetsubo grants Hida Bob a continous trait negating all force penalties on him. Continuous traits do not have a duration. They are "always on."
3. When two stats are exchanged, their current values are noted. Then, each stat is set to the other's current value, simultaneously. Any changes to stat values from an exchange do count as bonuses or penalties.
Various effects will set a stat to some particular value, such as effects that switch or copy stats. To set a stat to a value, give an appropriate bonus or penalty.
Moshi Taya's force is set to 9F and that involves a +7F bonus. Hida Bob's force is set to 2F and that involves a -7F penalty.
4. Taya's Battle action's effect is an ongoing effect.
5. The effects of Determination are neither continous nor instantaneous. It is an ongoing effect affecting in this case Taya's Battle action. Ongoing effects last until the end of the turn in which they occur unless otherwise indicated. Ongoing effects do not end if the card they came from leaves play.
The effect of Taya's Battle action cannot be negated and this is a non-continuous negation effect.
6. The effect of Iron Tetsubo on Hida Bob is continous, specifically a continuous negation effect, since it is a non-triggered continuous trait.
Alex Jones (rules official), 20 June 2008
Considering, for example, the scenario involving 2F Moshi Taya and 5F base Hida Bob with an Iron Tetsubo exchanging force with Determination taken as a reaction before Taya's Battle action was announced: Definitely, Taya will end up with 9F. Will Hida Bob end up with 2F or 9F?
Moshi Taya Battle: Exchange the Force of one of your target Naval Personalities with the Force of a target Personality opposing him.
Iron Tetsubo Negate all Force penalties on this Personality.
Determination Dark Virtue Reaction: Before you announce an action, target one of your Samurai: The action can not have its effects negated or have its targeting changed. After the action destroys any Personality, remove him from the game.
1. Moshi Taya is currently at 2F. Hida Bob is at 9F.
2. Iron Tetsubo grants Hida Bob a continous trait negating all force penalties on him. Continuous traits do not have a duration. They are "always on."
3. When two stats are exchanged, their current values are noted. Then, each stat is set to the other's current value, simultaneously. Any changes to stat values from an exchange do count as bonuses or penalties.
Various effects will set a stat to some particular value, such as effects that switch or copy stats. To set a stat to a value, give an appropriate bonus or penalty.
Moshi Taya's force is set to 9F and that involves a +7F bonus. Hida Bob's force is set to 2F and that involves a -7F penalty.
4. Taya's Battle action's effect is an ongoing effect.
5. The effects of Determination are neither continous nor instantaneous. It is an ongoing effect affecting in this case Taya's Battle action. Ongoing effects last until the end of the turn in which they occur unless otherwise indicated. Ongoing effects do not end if the card they came from leaves play.
The effect of Taya's Battle action cannot be negated and this is a non-continuous negation effect.
6. The effect of Iron Tetsubo on Hida Bob is continous, specifically a continuous negation effect, since it is a non-triggered continuous trait.
Duration of negation effects: "If a non-continuous negation effect uses “can not” wording, (such as, “Battle: A target Personality cannot be bowed,”) this is an ongoing effect that follows the normal rules of duration, prevents instantaneous effects from happening, prevents new ongoing effects from taking place, and negates ongoing or continuous effects."
Determination creates an ongoing effect that negates the Iron Tetsubo's continuous negation effect.