When a player is instructed to shuffle a pile of cards, what should be done?

When a player is instructed to shuffle a pile of cards, the primary requirement is that the cards must be randomized. This ensures that no player has an advantage based on the previous order of the cards, promoting fairness in gameplay. Shuffling serves to introduce a level of unpredictability and randomness to the game, allowing for a fresh start each time cards are drawn or played from the pile.

Randomization is achieved through methods such as overhand shuffling, riffle shuffling, or other techniques designed to mix the cards thoroughly. This process relies on the expectation that players will not be aware of the new order of the cards, which can significantly affect the outcome of a game.

The other choices do not align with the standard practice of shuffling: keeping the top card the same would defeat the purpose of shuffling, stacking the cards in order is contrary to the need for randomness, and not touching the cards at all would not fulfill the instruction to shuffle. Therefore, ensuring that the cards are randomized is the correct and valid action to take in this scenario.