What is a let serve in volleyball?

A let serve is when the ball clips the top of the net during a serve but still crosses into the opponent's court. Under current rules (since 2000), a let serve is legal and play continues.

Full Explanation

A "let" serve (also called a net serve) occurs when the served ball contacts the net cord or top tape and continues over into the receiving team's court. Per FIVB Rule 12.7.3, this is a legal serve and the rally continues. The change was adopted by FIVB in 2000; prior to that, any contact with the net on the serve was a fault. Under USAV, NFHS, and NCAA rules, the let serve is also legal. Receivers must be prepared to play a let serve since it can drop unpredictably near the net.

Rulesets covered: FIVB/USAV/NFHS/NCAA  |  Rule Reference: FIVB Rule 12.7.3