If a spell or ability instructs a player to play with the top card of their library revealed, what is this an example of?

When a spell or ability instructs a player to play with the top card of their library revealed, this situation exemplifies playing with an aspect of the game changed. Revealing the top card of a player's library modifies how they interact with that card during the game. It alters the visibility and strategic considerations of that card, allowing all players to see it and potentially affecting gameplay decisions, such as how one might respond to spells or abilities that reference the card on top of a library.

Playing a card refers to the action of casting a spell or putting a permanent onto the battlefield, while playing a land pertains specifically to placing a land card from a player's hand onto the battlefield. Hand size limitations refer to the maximum number of cards a player is allowed to have in their hand at any given time. None of these alternatives address the change in game state that comes from revealing the top card of the library, making the correct answer focused on the fundamental nature of how elements of play can be altered.