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, 23 March 2012
If a Mantis Clan player with Yoritomo's Guidance XP is attacking an enemy player with Ebisu's Honestly, what is the force of the province being attacked?
Yoritomo's Guidance XP reduces the force of a province under attack by a Mantis Clan player to 5 as a reaction to engaging, which is a one-time effect. Ebisu's Honesty says, "Your provinces have +2 strength," which is a static trait. The rulebook states that static effects re-check and re-apply constantly, so would the province's strength be raised to 7 by the Ebisu's Honesty after being reduced to 5 by the Yoritomo's Guidance XP?
For example, let's say I'm attacking into Carpenter's Castle, which has a base province strength of 9. I have Yoritomo's Guidance XP in play, and my opponent has Ebisu's Honesty, effectively giving his provinces a strength of 11. During my attack, when we engage at each province, Yoritomo's Guidance reduces the strength of the province to 5, once. Immediately, Ebisu's Honesty's static effect re-checks, and re-applies, so would that then raise the province's strength to 7?
If so, then what is the difference between the trait on Ebisu's honesty, and a personality with an attachment that conveys a force bonus? If I had a card that said, "Target an enemy personality; reduce his force to 0," but he has a Wyrmbone Katana, that gives him a +4 force bonus, would that bonus apply even after his force was reduced to 0, effectively leaving him at 4 force?
*edit: What about a case where you have a personality with a static force bonus as an on-card ability? For example, Yoritomo Minori says "Minori has +1 force for each other Magistrate in her army." If her force is reduced to 0, but there are two other Magistrates in her army, would that trait re-check, leaving her with an effective force of 2?
Jon Palmer (rules official), 23 March 2012
If a Mantis Clan player with Yoritomo's Guidance XP is attacking an enemy player with Ebisu's Honestly, what is the force of the province being attacked?
Yoritomo's Guidance XP reduces the force of a province under attack by a Mantis Clan player to 5 as a reaction to engaging, which is a one-time effect. Ebisu's Honesty says, "Your provinces have +2 strength," which is a static trait. The rulebook states that static effects re-check and re-apply constantly, so would the province's strength be raised to 7 by the Ebisu's Honesty after being reduced to 5 by the Yoritomo's Guidance XP?
For example, let's say I'm attacking into Carpenter's Castle, which has a base province strength of 9. I have Yoritomo's Guidance XP in play, and my opponent has Ebisu's Honesty, effectively giving his provinces a strength of 11. During my attack, when we engage at each province, Yoritomo's Guidance reduces the strength of the province to 5, once. Immediately, Ebisu's Honesty's static effect re-checks, and re-applies, so would that then raise the province's strength to 7?
If so, then what is the difference between the trait on Ebisu's honesty, and a personality with an attachment that conveys a force bonus? If I had a card that said, "Target an enemy personality; reduce his force to 0," but he has a Wyrmbone Katana, that gives him a +4 force bonus, would that bonus apply even after his force was reduced to 0, effectively leaving him at 4 force?
*edit: What about a case where you have a personality with a static force bonus as an on-card ability? For example, Yoritomo Minori says "Minori has +1 force for each other Magistrate in her army." If her force is reduced to 0, but there are two other Magistrates in her army, would that trait re-check, leaving her with an effective force of 2?
Please see the rules for Calculating stats. In your first example, the Province's base strength is 9, increased by Ebisu's Honesty by 2 to 11. When Yoritomo's Guidance takes effect, it lowers the Province strength to 5, and does so by giving it a penalty equal to the difference between the current strength and 5, in this case 6. So the province strength is calculated as 9 + 2 - 6 = 5. If you were then to use Indomitable Home to give a +2 bonus to the Province strength, it would become 9 + 2 - 6 + 2 = 7.
The same is true of calculating force totals. When stats are set to a number, simply add the bonus or penalty of the difference to all other modifiers. Minori would be 4 + 2 - 6 = 0, but if another Magistrate subsequently moved into her army, she would become 4 + 3 - 6 = 1.