Hidden Card Error


Hidden Card Error, or HCE, is the newest addition to the IPG. The previous iteration of the infraction was Drawing Extra Cards (DEC). The penalty for DEC was a GL, and with the trend of lowering the severity of infractions and penalties, DEC was targeted for a change.


Lowering a penalty from GL to a Warning is not always as easy as updating the penalty in the IPG. DEC is a penalty that can provide a great advantage, because the extra card might be the difference between winning or losing a game. Because the penalty used to be a GL, there was no fix for the situation, and awarding a Warning and letting the game proceed is not good enough. A warning is not harsh enough for people to avoid drawing extra cards, and it doesn’t negate the potential advantage gained.


While creating a way to fix the game state, a few guidelines were created:

  • A warning by its own doesn’t negate the advantage

  • Returning a card at random will rarely fully negate the advantage

  • A judge should never make any strategic decisions for the players


From that, a new fix was born: Let the opponent look at the hand and decide what card is considers the extra card drawn. Because the opponent gets to look at the hand and choose whatever they like, the advantage of an extra card becomes a disadvantage, but it’s still much better than immediately losing the game.


Once this solution came to be, other situations that were previously covered by other parts of the IPG could now be fixed in the same way, so they were all moved into a new infraction - Hidden Card Error - and the DEC infraction was removed.

The Infraction

Now that we know how this infraction came to be, let’s talk about the reasoning behind the definition and the fix of this infraction.


Three conditions should be met for an infraction to be HCE:

  1. Knowing all the public information isn’t enough to correct the error

  2. The error was committed without the opponent’s permission

  3. It’s not a dexterity error

If any of the conditions isn’t met, it isn’t HCE.


Once we determined that we’re in the HCE realm, we have some decisions to make:

  • What hidden zones were involved?

  • Are there extra cards to take care of?

  • Is there missing information that should be public?

The answer for the first question is usually very easy, and the answer is almost always “the hand”, “some portion of the library”, or both. In some less common cases, exiled cards or cards from other zones can be involved.


The second question might seem odd. How can there be no extra card? Well, here’s where HCE is different from its DEC roots. The third question might give you a hint about when the second answer might be “no”. If, for example, a card instructs a player to search the library for a basic land, reveal it, and put it into that player’s hand, but the player doesn’t reveal the card, then there are no extra cards, but there was still an error that involved non-public information, there was no permission from the opponent and the action was definitely not a dexterity error.


Once we know where the cards came from and where they went, as well as what information should be public, we can start fixing the game state. If there are any extra cards, ask the opponent to choose which cards shouldn’t be there and return them to the correct zone. If that zone is the library, shuffle them into the unknown portion (we’ll cover a small exception later). If the number of cards is correct, but should have been revealed to the opponent, let the opponent choose what card wasn’t revealed, and perform any actions that should have taken. If the card doesn’t meet some criteria (being a basic land, if we use the previous example), return it to where it came from and let the player look for a new card.


When fixing the situation, there are some things to consider. If the position of a card in a library was previously known (player drew an extra card after “scry 2” with both on top, for example), put it back where it was; if some of the cards are known to the opponent (e.g. the player revealed them from his hand), the opponent can’t choose those those cards as if they were not known; and if you can use smaller sets of cards, do so.


Oh, and don’t forget the warning.


Now you most of the ins and outs of HCE, but nothing is better than reading the real thing, so:

HCE section in the IPG (IPG 2.3)

Definition of card sets (IPG 1.5)


You can also read Toby Elliott’s blog for more details.


In this part you will find several game states. Your mission, should you choose to accept it, is to decide what went wrong and how to fix it. For each situation, please answer these three questions:


  1. What is the infraction (and why)?

  2. What is the penalty (and to which player)?

  3. How do you fix it (and why)?


1. Situation 1

AP resolves a Divination that was cast for 2R.

2. Situation 2

AP looks at the top 8 cards of his library while resolving a Dig Through Time.

3. Situation 3

AP points out her Dark Confidant trigger, doesn’t reveal the card then draws another card.

4. Situation 4

AP resolves Sylvan Scrying and puts a card into his hand without revealing it.

5. Situation 5

AP puts a Lightning Bolt into his hand after it resolves.

6. Situation 6

AP taps three Swamps, casts Painful Truths and asks "Draw three?", to which NAP replies by saying “sure”, so AP draws three cards.

7. Situation 7

AP casts Serum Visions, draws a card, scrys 2, leaves both on top and then draws another card.

8. Situation 8

AP mulligans, keeps her six cards, then scrys two.

9. Situation 9

NAP cast Duress and choose a card on his turn. It’s now AP turn and he accidentally draws two cards during his draw step.

10. Situation 10

While scrying 2, AP accidentally shuffles the scried cards into his library.