What is the term used when a player serves the ball and it directly hits the opponent’s court without anyone touching it?

The term used when a player serves the ball and it lands directly in the opponent’s court without anyone touching it is known as an ace. Achieving an ace demonstrates a successful serve that is both difficult for the receiving team to handle and results in a point for the serving team. This situation highlights a player's skill in serving, as the ball must be delivered with the right speed and placement to catch the opponents off guard.

Other terms listed in the question have distinct meanings: a spike refers to an offensive hit by a player to score points, typically executed during volley play rather than during a serve. A service error is when the server fails to successfully execute the serve according to the rules, while a fault is a violation of the serving rules that results in a point for the opposing team. Understanding the definition of an ace is crucial for identifying successful serve strategies in volleyball.