What do state-based actions check for?

State-based actions are specific actions that the game automatically checks for and resolves without needing player intervention. These actions are crucial for maintaining the integrity of the game state. The correct answer indicates that state-based actions check for any game-changing conditions, which includes a variety of scenarios.

For instance, state-based actions check for situations such as a player having zero or less life, a creature with lethal damage marked on it, or a player possessing an illegal combination of cards that would result in a game loss (like having two of the same "legendary" permanent). These checks ensure that all players are abiding by the game's rules and maintain a balanced state of play.

This approach means that any significant alteration to the game state—be it from life totals, permanents on the battlefield, or a player violating a rule—is assessed and addressed through state-based actions. Thus, the answer encapsulates the broad scope of conditions checked by state-based actions, which can drastically affect the outcome of the game.