Which action can lead to Looking at Extra Cards?

Looking at Extra Cards often occurs when a player observes the face of a hidden card. This action breaches game rules because players are not permitted to gain information about hidden cards unless they are the card owner or have explicit permission to view them. In this context, "hidden cards" typically refer to cards that are not meant to be revealed to opponents, such as cards in a player's hand or cards in a library. Observing the face of such a card can grant an unfair advantage, leading to a potential infraction in the game.

In contrast, actions like playing a land, discarding a card, or shuffling a hand do not inherently create situations where extra cards might be seen or accessed improperly. These actions are part of standard gameplay where the risk of revealing hidden information is minimal, provided they are conducted correctly. For example, shuffling a hand or discarding a card generally does not involve looking at or revealing hidden information to the opponent. Thus, these options don't lead to the infraction in question.