I'm breaking this away from the CoCo thread, since it is a different scenario.

A player plays the following cards and fails to reveal the searched-for cards:

Fertile Thicket
Conduit of Ruin

Is our fix:

A) Have the player reveal the card to their opponent. Issue a Warning for GRV. No further action.
B) Have the player reveal the card to their opponent. Issue Warning for HCE. No further action.
C) Have the player reveal the card to their opponent. Issue Warning for HCE. Shuffle the excess card into the unknown portion of the library.

Continued from here:

Originally posted by Dan Collins:

Oh, the top of your library is publicly available information? So it would
be fine if a spectator were to stop by and look at the top card of your
library in the middle of a game?

I'm not convinced that publicly available are the words that should have
been used here.

If I ask you “which card did the player put on top with Fertile Thicket,” you can point to the top card. You will not accidentally point to the second card from the top, or a card in the hand, or a face-down creature in play. So yes, it's publicly available.

Contrast that to putting a card into your hand, where it's mixed in with all the other cards. You have no way of knowing which card was just put into the hand. Or at least, theoretically you don't; in practice, sometimes you can tell, but the other player can shuffle his hand at any time. The same is not true of his library.

The fix that “feels correct” is definitely

B) Have the player reveal the card to their opponent. Issue Warning for HCE. No further action.

The card was supposed to be revealed to prove it was a legal choice for the effect, and is the only object at that location (the top card of the library). This fits the HCE definition given that it is hidden both before and after, but differs from adding it to the hand, and completely repairs the game state without offering advantage.

The way HCE reads, it would appear that the solution is

C) Have the player reveal the card to their opponent. Issue Warning for HCE. Shuffle the excess card into the unknown portion of the library.

And that this solution would also be used for an effect like +1 on Domri Rade when the player takes the card into an empty hand. It seems like we should just be able to reveal the information, give the Warning, and move on. Shuffling the card back in when we know exactly which one it was feels incorrect.

Also, this line from HCE would seem to indicate it is intended for situations where the game state cannot be corrected, but here it can be?

Originally posted by IPG 2.3, Philosophy:

Though the game state cannot be reversed to the ‘correct’ state, this error can be offset by giving the opponent sufficient knowledge and ability to correct the error so that it cannot generate advantage.

From HCE:

This infraction only applies when an unknown card is in a hidden location both before and after the error. If cards are placed into a public zone their order is known and the infraction can behandled as a Game Rule Violation. Order cannot be determined from card faces only visible to one player unless the zone in question contains only a single card.

(emphasis mine)

Eli the wording of HCE contradicts your definition of publicly available.

FWIW I want the fix to be “Reveal the card”, but the current wording of HCE doesn't support that.

Jacob FYI Domri into an empty hand can be a simple reveal since the zone has a single card.

Edited Jeff S Higgins (Jan. 27, 2016 03:19:36 PM)

So the rule's language is a little unclear, actually. The beginning talks about not applying HCE if “the zone in question” has only one card. However, the remedy section doesn't discuss zones–rather, the fix discusses “the complete set of cards that contains the unrecoverable information.” It seems to me that the implication (though I'll admit, not the letter) of policy would be to not apply this fix to this error because the “complete set of cards” is a single card, even if that set of cards does not technically comprise a zone.

Edited Eli Meyer (Jan. 27, 2016 03:26:29 PM)

The answer is (A) - it's not HCE, because the error can be corrected with public information (the location of that card), or it could have been, and we won't reward the opponent for noticing after it gets to be uncorrectable. IPG: “Be careful not to apply this infraction in situations where a publicly-correctable error subsequently leads to an uncorrectable situation.”

Note that says "{don't} apply this infraction…" - so HCE isn't the infraction, and the remedy isn't appropriate, either.

If we tweak Jeff's scenarios slightly, and the unrevealed card goes straight to hand instead of the top of the library, then HCE very much applies, and someone just wasted a tutor effect.

d:^D

I chose the scenarios carefully knowing they'll come up at the weekend limited grand prix.

Originally posted by Scott Marshall:

If we tweak Jeff's scenarios slightly, and the unrevealed card goes straight to hand instead of the top of the library, then HCE very much applies, and someone just wasted a tutor effect.

d:^D

Painful Memories then shuffle your deck?