Defensive three-second violation

Basketball rules infraction in the NBA

A defensive three-second violation, also known as illegal defense, is a basketball rules infraction in the National Basketball Association (NBA), which was added prior to the 2001–2002 season. It is assessed when a member of the defending team spends more than three seconds in the free throw lane while not actively guarding an opponent. To be considered actively guarding an opponent, a defender must be within arm's length of an opponent and must be in a guarding position. A violation will not be called if an offensive player is in the act of shooting, if the offensive team loses control of the ball, if it is imminent that the defender's position will become legal, or if the defender is guarding a player who has possession of the ball.

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