A let serve is a term used for a serve that hits the net and lands in the correct area. This type of serve is considered to be an acceptable outcome, as long as it does not touch any part of the net. Let serves are most commonly seen in tennis, where players have to abide by strict rules regarding serving. In addition, let serves can also be seen during badminton matches and other similar sports. Additionally, let serves are often used when playing table tennis or beach volleyball.