This is a collection of rulings on various cards that interact with the conflict declaration process, but I'll put this chart at the top that should combine all the rulings.

(a) Attacking Player announces they will declare a conflict
===Interrupt Window (1) : "When Player declares a conflict / When a conflict is declared" (7 Stings Keep)===
===Resolution begins: "A Conflict is Declared”===
i. If Tadakatsu is in play, defender chooses ring first.
ii. Attacking player chooses conflict elements - ring, province, attackers, etc.
iii. Attacking player pays costs to declare attackers (Caravan Guard) and the attack initiates.
===Interrupt Window (2) : "When a conflict is declared, before province reveal" (Know the Terrain)===
===Resolution begins: "A conflict is declared, before reveal” ===
(b) Conflict Begins. choices from i and ii take effect - attackers are participating, attacked province was declared, ring is contested.
(c) Attacker takes ring fate, covert is chosen and resolves.
===Resolution complete: "A conflict is declared, before province reveal"===
===Reaction window (1): After a conflict is declared, before reveal" (The Crashing Wave)===
(d) Province is revealed, if facedown.
===Reaction window (2): “After a conflict is declared…”, simultaneous reactions to (b), (c) and (d) ===
(e) Defending Player declares defenders, if needed.

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Is there a difference in the timing windows for "The Crashing Wave" and "Know the Terrain"? One is "Reaction: After an attack is declared against a province but before the province is revealed", the other is "Interrupt: When an attack is declared against a non-stronghold facedown province you control, before revealing that province" It seems like they share a triggering condition (after the attack, but before the reveal); is there a functional difference to one being an interrupt vs the other being a reaction (outside of cards that care like Kuzunobu)? In the event that there is a difference, what are some things that happen between these two trigger points?

There is a slight difference, which is that Know the Terrain is played before the conflict is declared whereas The Crashing Wave is played after the conflict is declared (but before revealing the province). Mostly this just means that in-conflict effects are active, though I’ll admit I can’t think of any off the top of my head. I guess it would matter if Master of Gisei Toshi were preventing The Crashing Wave from being played, whereas Master couldn’t prevent the Know the Terrain?

[Tyler Parrott, Jan 27 2020]

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Thanks for the answer, but I think I might still be a bit confused about the timing of these. Is this a correct interpretation?

Step 1) Ring is selected, province is selected, conflict type is selected, attackers are selected, ring fate is taken.

Step 2) Conflict is declared, and attackers are considered participating.

Step 3) Province is revealed.

Step 4) Conflict starts.

It sounds like Crashing Wave reacts after Step 1 and before Step 2. As a result, characters are not considered to be participating yet, and cards like Guest of Honor and Ageless Crone don't interact with Crashing Wave.

Know the Terrain interrupts Step 3, which means characters are considered to be attacking and Guest of Honor and Ageless Crone would interact with it.

Is this a correct interpretation? Is ring fate taken before Crashing Wave can initiate (relevant for the new phoenix cancel)? What happens if my only attacking character dies (ex: Castigated & Forged Edict) or is bowed (from a theoretical card that can cancel an event, + kirei ko) while interacting with Crashing Wave? What about with Know the Terrain?

Know the Terrain interrupts “when a conflict is declared against a facedown province,” and the “before the province is revealed” is primarily there to ensure that players don’t accidentally reveal the province before resolving Know the Terrain. The “when a conflict is declared” interrupt window happens after the selections are made (ring, type, attackers, province) but before actually resolving any of those selections (that’s how interrupts work). Therefore, the conflict has not actually begun while Know the Terrain is resolving.

In contrast, Crashing Wave reacts after the conflict is declared, but before the facedown province (if applicable) is revealed. This places it in the same timing window as covert (though covert technically occurs first as it’s a keyword). The attacking player has already gained fate from the declared ring when Crashing Wave is played. Characters are participating at this point.

Here’s a little chart that hopefully helps:

1. 1. Interrupt window: A conflict is declared against a facedown province—Know the Terrain is played.

   2. If Tadakatsu is in play, choose the element first.

2. Attacking player declares characters, conflict type, element, and province.

3. Fate from the contested ring goes to the attacking player, covert is chosen and resolves.

3. 1. Special “The Crashing Wave” reaction window occurs.

4. If the province is facedown, it is revealed.

5. Reaction window for steps b-d, above. (Note that Tengu Sensei will trigger even if covert failed to resolve.)

6. Declare defenders.

If your only attacker dies while resolving The Crashing Wave, then the conflict continues to resolve and you can move or play characters into the conflict. It has already been declared. If your only attacker dies while resolving Know the Terrain, then it was never attacking to begin with and your conflict declaration opportunity fails to resolve (you may still declare the same conflict type again, and the conflict was not considered passed, you’re just down a conflict opportunity for the round).

[Tyler Parrott, Mar 2 2020]

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Thanks for this, helps a lot with the difference between the two! I have one final question about The Crashing Wave. Say my opponent attacks into Secret Cache (faceup), and I play The Crashing Wave to move the conflict to Midnight Revels. Which province reaction do I get to trigger? They both react to "After a conflict has been declared against this province".

The attack was declared against Secret Cache, so Cache gets to trigger. Midnight Revels does not, as the conflict was moved to it (not declared).

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this is a question about timing. the following cards: Tengu Sensei, Kituski Yuikimi, midnight revels, Shiro Kitsuki, and Trusted Advisor are they all in the same timing? meaning if Kituski Yuikimi hits a Midnight Revels is it whoever has first player token gets to basically win that interaction? or are the reactions all at different time periods like when covert happens tengu sensei goes off when the fate is grabbed Kituski Yuikimi and trusted advisor go off. in other words, I'm trying to figure out how the timing exactly goes for those cards, if they are streamed lined in the same reaction window or if they all over the place. (i hope this doesn't confuse you, thank you again for your hard work.)

The next Rules Reference will explicitly call out covert, but covert happens before the province is revealed/engaged. Everything else happens at the same time. So:

Framework: Declare attackers (and covert), province, ring, type.
Reaction: Covert initiates & resolves (Tengu Sensei)
Framework: Above declarations simultaneously engage. Reveal engaged province.
Reactions: Attackers declared, province revealed/engaged (Midnight Revels), ring becomes contested (Yuikimi & Trusted Advisor), conflict declared (Shiro Kitsuki)

All of the above reactions trigger one-at-a-time back and forth between the players, starting with the first player (as with any reaction window).

[Tyler Parrott, Sep 13 2019]