IPG 2.3 Game Play Error — Hidden Card Error


A player commits an error in the game that cannot be corrected by only publicly available information.

It is not a Hidden Card Error if the opponent acknowledges the action or controls the continuous effect modifying the game rule that made the action illegal.

This infraction only applies when a card whose identity is known to only one player is in a hidden set of cards both before and after the error.

If an additional card is seen but not added to the set, the infraction is Game Play Error–Looking at Extra Cards.


  • A. A player draws four cards after casting Ancestral Recall.
  • B. A player scries two cards when they should only have scried one.
  • C. A player resolves a Dark Confidant trigger, but forgets to reveal the card before putting it into their hand.
  • D. A player has more cards in their hand than can be accounted for.
  • E. A player casts Anticipate and picks up the top four cards of their library.
  • F. A player, going first, draws for their turn.


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

If cards are placed into a public zone, then their order is known and the infraction can be handled as a Game Rule Violation.

Order cannot be determined from card faces only visible to one player unless the card is in a uniquely identifiable position (such as on top of the library, or as the only card in hand.)

Be careful not to apply this infraction in situations where a publicly-correctable error subsequently leads to an uncorrectable situation such as a Brainstorm cast using green mana. In these situations, the infraction is based on that root cause.

Information about cards previously known by the opponent, such as cards previously revealed while on the top of the library or by a previous look at the hand, may be taken into account while determining the set of cards to which the remedy applies.

Always operate on the smallest set possible to remedy the error. This may mean applying the remedy to only part of a set defined by an instruction. For example, if a player resolves Collected Company, picks up three cards with one hand and then four cards with the other, the last drawn set of four cards should be used for the remedy, instead of the full set of seven cards.

Additional Remedy

In cases where the infraction was immediately followed by moving a card from the affected set to a known location, such as by discarding, putting cards on top of the library, or playing a land, a simple backup to the point just after the error may be performed.

If the set of cards that contained the problem no longer exists, there is no remedy to be applied.

If the error put cards into a set prematurely and other operations involving cards in the set should have been performed first, the player reveals the set of cards that contains the excess and their opponent chooses a number of previously-unknown cards. Put those cards aside until the point at which they should have been legally added, then return them to the set.

If the error involves one or more cards that were supposed to be revealed, the player reveals the set of cards that contains the unrevealed cards and their opponent chooses that many previously-unknown cards. Treat those as the cards that were ‘revealed’ and return them to the set that was being selected from; the player then reperforms the action. If recreating the original selection set and reperforming the action would be too disruptive, leave the selected cards in hand.

If a set affected by the error contains more cards than it is supposed to contain, the player reveals the set of cards that contain the excess and their opponent chooses a number of previously unknown-cards sufficient to reduce the set to the correct size. These excess cards are returned to the correct location. If that location is the library, they should be shuffled into the random portion unless the owner previously knew the identity of the card/cards illegally moved; that many cards, chosen by the opponent, are returned to the original location instead. For example, if a player playing with Sphinx of Jwar Isle illegally draws a card, that card should be returned to the top of the library.


If a face-down card cast using a morph ability is discovered during the game to not have a morph ability, the penalty is a Game Loss. If the player has one or more cards with a morph ability in hand, has not added previously unknown cards to their hand since casting the card found in violation, and has discovered the error themselves, the upgrade does not apply and they may swap the card for a card with the morph ability in hand.