With a current lack of an Unofficial FAQ document, I have compiled this one based on questions and answers I have sourced from multiple sites.
This is not intended to be the 'holy grail' of FAQs.
It's not perfect. It's very much far from perfect.
And it still has a number of rulings that I need to copy across.

Like the Rules Reference (RR), this will evolve.
The plan is not to allow it to balloon out to an immense size.
For now, there are a number of questions for things that can easily be found in the RR.

The Learn to Play rule book, and the Rules Reference, are daunting documents.
But I encourage you to read them in their entirety, at least once.

Obviously, I'll ask to have this moved once the Rules sub-forum opens up.

GENERAL QUESTIONS

Where can I find the rules?
The Learn To Play rule book can be found in the Core Set.
The Rules Reference is a digital rule book, and will evolve over time.
The latest versions can be found by following this link, and scrolling to the Rules section under Support.
www.fantasyflightgames.com/en/products/legend-of-the-five-rings-the-card-game/

How many core set boxes will I need?
ANSWER:
One to play.
Two to compete.
Three for playset.

What’s in the Core Set?
ANSWER: Each single core set contains 1 of each clan card, 2 of each neutral conflict card, and 3 of each neutral dynasty card - except the Keeper and Seeker Initiates and the neutral holdings, of which there are 2 each.

How do I tell the difference between a Dynasty and Conflict card?
ANSWER: Look at the back of the card.
Alternatively, Conflict cards and Dynasty cards are distinguished by the 'C' or 'D' in the bottom right-hand corner.

What is my clan’s current role?
Crab: Keeper of Earth
Crane: Seeker of Air
Dragon: Seeker of Fire
Lion: Keeper of Fire
Phoenix: Keeper of Water
Scorpion: Seeker of Void
Unicorn: Keeper of Void

GENERAL PLAY QUESTIONS

ACTIONS
When can I play events/attachments?
ANSWER: Check out pages 18 and 19 in the Rules Reference document.
Here, you can find the Framework. It’s a handy breakdown of the main timing sequences in the game.
Events can be played in any of the Action Windows.
Similarly, attachments can be played in all Action Windows, except the one in the Dynasty Phase.

ABILITIES
Unless otherwise specified in a card’s text, all Abilities can only be triggered once per turn.
Abilities can be triggered even if the card is bowed, unless the ability requires the card to bow as a cost.

KEYWORDS
Keywords resolve as soon as their specified timing point is met, before any reactions to that timing point can be triggered.
[Answered by Nate French, 09/08/2017]

LASTING EFFECTS
Lasting effects do last, but they only check their activation effects when they are triggered.
So, for cards like the Dragon Stronghold or Hida Guardian, changing the amount of attachments or holdings in the middle of the conflict, but after their bonuses are given out, won't change the bonuses they gave.

Will it be possible to do the old CCG trick of declaring an attack/conflict at a province and then not sending anyone to the battle?
ANSWER: No.
At least one character must be declared as an attacker... in order to initiate a conflict.
[Rules Reference: Page 21: Framework 3.2 Declare Conflict]

When Kakita Kaezin finds himself dueling the Otomo Courier (which could happen in a political conflict), what happens?
ANSWER: This duel cannot happen.
A character with a dash skill value cannot be a challenger or challengee in a duel of that skill type.
[Rules Reference: Page 5: Dash(-) ]

Do bowed attachments contribute force to a conflict, assuming the character is still ready?
ANSWER: Yes.
If an attachment has skill modifiers, those modifiers apply to the skill of the attached character. Such modifiers apply to the character even while the attachment is bowed.
[Rules Reference: Page 3: Attachment Cards ]

Does the term ‘Sacrifice’ have any mechanical difference to ‘Discard’?
ANSWER: Yes.
Sacrificing a card does not satisfy other means (such as “discard”) of a card leaving play.
[Rules Reference: Page 14: Sacrifice ]

If I take control of an honored character that I do not own, who gains the honor if they leave play before they are returned to their owner?
ANSWER: You will gain the 1 honor.
When a card leaves play:
If a card would enter an out-of-play area of a player who does not own the card, the card is placed in its owner’s equivalent out-of-play area instead. (For all associated card ability and framework effect purposes, the card is considered to have entered that opponent’s out-of-play area, and only the physical placement of the card is adjusted.)
[Rules Reference: Page 4: Control and Ownership ]

What happens when I want to play an attachment with restricted keyword on a character with restricted attachments already attached? Or can I not do this?
ANSWER: One of the attachments must be discarded.
If at any time a character has three or more restricted attachments, that character’s controller must immediately choose and discard one of the restricted attachments on the character as soon as the illegal game state occurs.
[Rules Reference: Page 13: Restricted]

Can a player discard a copy of a unique character to add a fate to a unique dynasty character in play during the conflict phase?
ANSWER: No.
A player may, as a player action during step 1.4 of the dynasty phase...
[Rules Reference: Page 6: Duplicates]

If I declare a Political conflict as my first conflict and my opponent switches the conflict type to Military (Kuroi Mori, Captive Audience), am I able to declare Political again for my second conflict this round?
ANSWER: No. Declaring a conflict type is independent of what the conflict turns into via game effects.
During the conflict phase, each player is granted one opportunity to declare a military conflict and one opportunity to declare a political conflict.
[Rules Reference: Page 20: Framework 3.2 Declare Conflict]

DASH (-) SKILLS
Can Doji Challenger target Otomo Courtier to bring it into a conflict?
ANSWER: No

Can Bayushi Yunako use her ability to switch the stats of someone who has a dash skill?
ANSWER: No
If a character has a dash skill value, that skill value cannot be modified or otherwise changed by card abilities and effects.
[Rules Reference: Page 5: Dash]
Can you Charge a character with a Dash skill value?
ANSWER: No
A character that cannot participate in a conflict would not be able to enter a conflict they cannot participate so they would remain in province with the game state unchanged.
[Answered by Nate French, 23/08/2017]

SPECIFIC CARD QUESTIONS

HEIGHT OF FASHION
When can I play Height of Fashion?
ANSWER: Height of Fashion “cannot be played during a conflict”.
It cannot be played during the Dynasty Phase (No attachment can).
It cannot be played during a conflict, but can be played during the Conflict Phase.
Thus, it cannot be played in the Conflict Action Window (3.2.2).
It can be played during any other Action Window.

WAY OF THE LION
If I play two Way of the Lions on one character in the same conflict will it quadruple its base strength? Or triple it? Or the second Way of the Lion has no effect?
ANSWER: It effectively adds the base Mil. So a second one will add the base Mil again. (Livestream June 24)

TOGASHI KAZUE
Can a player add a fate to Togashi Kazue, who is in play as a attachment, by discarding a second copy of Kazue from their conflict hand?
ANSWER: No. Kazue is played “as an attachment”, thus changes cardtype. Duplicate rule refers to characters.
If an ability causes a card to change its cardtype, the card loses all other cardtypes it might possess and functions as would any card of the new cardtype.
[Rules Reference: Page 3: Cardtype]
A duplicate is a copy (in a player’s hand or provinces) of a unique character that is already in play and under the same player’s control.
[Rules Reference: Page 6: Duplicates]

ELEMENTAL FURY
What happens to the fate on an unclaimed Ring when it is switched to by Elemental Fury? Does the attacker get the fate as well?
ANSWER: Yes.
When a ring becomes the contested ring in a conflict, move all fate on that ring to the attacking player’s fate pool.
[Rules Reference: Page 14: Rings]

CLOUD THE MIND
Can you use Cloud the Mind to blank Hida Kisada's text box? Or is their text considered a trait?
ANSWER: Hida Kisasa two traits: Bushi and Champion. The rest of the text, other than flavor text, is a constant ability. The constant ability will be blanked.
Most cards have one or more traits listed at the top of the text box and printed in Bold Italics
[Rules Reference: Page 16: Traits]

Blanking effects (like Cloud the Memory) do not trigger the "cards leaving play" for abilities they may have blanked. So if you've used some character's action, then they get Clouded, then the Cloud is removed, the action is still considered to have been used even though it vanished for a while.

BLACKMAIL
Does Blackmail work with Spies at Court? Can you take control of the opponent's character, dishonor it, discard cards from your opponent's hand, and then return this dishonored character back to its owner?
ANSWER: Yes. A Blackmailed character is returned at the end of the conflict (3.5), while Spies at Court is played when the conflict is won (3.2.3).

What happens to an attached Way of the Dragon when a character I control is the target of Blackmail?
ANSWER: Way of the Dragon is discarded, as it is no longer attached to a character you control.
“Attach to X” is a continuous check. If X is not true, it becomes an illegal attachment.
If a situation arises in which an attachment is not legally attached, discard the attachment.
[Rules Reference: Page 3: Attachment Cards]

REPRIEVE
If I have Reprieve on an honored character that I use for Noble Sacrifice, can I use Reprieve to save the character and still get to discard an opponent's dishonored character?
ANSWER: No.
If the selected card does not leave play, the sacrifice is not considered to have been made.
[Rules Reference: Page 14: Sacrifice]

TOGASHI YOKUNI
Togashi Yokuni copies the ability on an Adept of Shadows. Can Yokuni be returned to a player’s hand?
ANSWER: Yes. Nothing prevents it. That copy can then be played as if he were a conflict character, or discarded as a Duplicate. If an effect discards a random card from the player’s hand (Ring of Earth), use a die to pick randomly.
[Answered by Brad on Discord]

Togashi Yokuni’s ability copies another triggered ability “until the end of the phase”. If Yokuni copies Shiba Tsukune’s interrupt that triggers “When the conflict phase ends”, will Yokuni be able to use the interrupt or will he lose it before it triggers?
ANSWER: Yes. Shiba Tsukune’s ability is an Interrupt Ability, so will be resolved before the triggering condition of the conflict phase ending.
[Rules Reference: Page 16: Triggering Condition]
[Confirmed by Brad on August 5 Live Stream]

LET GO
If I play Let Go, choosing an opponent’s Watch Commander, do I lose an honor?
ANSWER: Yes.
Let Go is played. Watch Commander reacts to the card being played. Then the effects of Let Go resolve.
[Rules Reference: Page 9: Initiating Abilities / Playing Cards]
[Answered by Brad on August 5 Live Stream]

STEWARD OF LAW
Steward of Law will only protect a character from gaining the Dishonored status.
It will not prevent a character from going from Honored to Ordinary.
[Answered by Brad on August 5 Live Stream]

HIDA KISADA
Will Kisada’s constant ability cancel an opponent’s Voice of Honor of it is the first card they play?
ANSWER. No
Kisada's ability reads that he can “cancel the effects of the first action ability your opponent triggers...".
This means his ability only affects those abilities with the keyword "Action".
Triggered abilities fall into one of the following types: actions, interrupts, and reactions.
[Rules Reference: Page 16: Triggered Abilities]

SHINJO TATSUO
If Tatsuo is participating in a conflict, can he use his ability to move himself and another non-participating character to the conflict?
ANSWER: No
A card is not an eligible target or an ability if the resolution of that ability’s effect could not affect the target at all.
[Rules Reference: Page 16: Target]
[Answered by Nate French, 23/08/2017]

SHIBA PEACEMAKER
What happens if Shiba Peacemaker targeted with Blackmail?
ANSWER: Cannot participate status is a binary check to see if a character is eligible to participate in the conflict they are participating in. When control of the Shiba Peacemaker changes, the character would no longer be able to participate and would be sent home bowed.
[Answered by Nate French, 23/08/2017]

AMBUSH
Do I need to reveal the character that I'm going to put from hand? Or just any eligible target?
ANSWER: Yes. Part of declaring your intention to trigger Ambush is to indicate which character(s) you intend to put into play, which will be revealed (though not leave your hand) when checking the play restrictions for triggering the ability (Step 1 of the initiation sequence). As such, the decision to cancel (in Step 6) is made with full knowledge of which character will actually be put into play by the successful resolution of the ability.
[Answered by Nate French, 23/08/2017]

IKOMA EIJI
Can Ikoma Eiji put Deathseeker into play participating in the conflict, allowing the Deathseeker to also trigger?
ANSWER: No.
The Rules Reference Guide only gives the player the option of putting the character into play directly into a conflict if it is played from hand during a conflict. Since it is being put into play and is not coming from hand it does not have this option and is placed in the home area.
[TBD: Find references]
[Answered by Nate French, 23/08/2017]

Good work, though I have a suggestion, in:

ABILITIES
Unless otherwise specified in a card’s text, all Abilities can only be triggered once per turn.
Abilities can be triggered even if the card is bowed, unless the ability requires the card to bow as a cost.

I would mention that a card's state is considered to be reset when it leaves play, so you can trigger it again if it comes back into play (Example: Kitsu Spiritcaller, Rebuild). I asked this during the Kiku Matsuri and got this ruling (He had to check up the chain some first). The exception, of course, being the max per time period limits.

Well done.

10 hours ago, Bayushi Shunsuke said:

DASH (-) SKILLS
Can Doji Challenger target Otomo Courtier to bring it into a conflict?
ANSWER: No

If you need a source on this one it would be

"If a character cannot participate in a conflict, that character cannot be declared as an attacker or defender for, move into, or be played into that conflict. If an already participating character gains cannot participate status during a conflict, move it home bowed." p.12

15 hours ago, Bayushi Shunsuke said:

DASH (-) SKILLS
Can Doji Challenger target Otomo Courtier to bring it into a conflict?
ANSWER: No

In addition, I assume this answer also applies to Yogo Hiroue .

1 hour ago, TroutNinja said:

In addition, I assume this answer also applies to Yogo Hiroue .

Yes, most definitely - in the case of a military conflict.

This should probably be updated with the 'Way of the Lion' change.
This just caused some confusion in our group, with this page not having the new ruling for the card.

Hello,

I have a question : about Blackmail , when you do it on a character that is in an opposing army during battle, does the character switch side and come to your side in the battle, or is he joining you but in your home, outside of the ongoing battle ? If you have the answer, please tell me the reason why it is as such. As a friend of mine observed, it is not told on the card that the newly controlled character join the battle on the scorpion's side, only that it is now controlled by the scorpion player, that's why we're quite disturbed it.

Thanks by advance, I'm really impatient to have your answer.

Best wishes,

Pandaladin

Seeing as how all my google searches result in this thread, could you make a link to the rules reference at the top of your post?

Please update the current clan roles.

11 hours ago, Akodo Tetsuo said:

Please update the current clan roles.

I've updated the post with the new roles.

Working on a big update on the rulings document.
When complete I'll post it to the Rules subforum, rather than here.

Saw this last night...

If a opponents card effects bring one of my characters into a military conflict when pacifism is already attached to that same character, what happens?

Is that character ineligible for the effect? Does the character come into the conflict then immediately go home bowed?

Thanks!

If a character "cannot participate" in a conflict (because of a dash or specific card text such as Pacifism or Shiba Peacemaker), that character is not a legal target for an effect that would bring it into the conflict. A character is sent home bowed only if it was legally participating in a conflict and an effect changed things so that the character's participation is no longer legal. For instance, a character with Pacifism is in a POL conflict and the conflict type is changed to MIL; or a defending Shiba Peacemaker is affected by Blackmail.