Defensive three-second violation, also known as illegal defense, is a rule violation in the National Basketball Association. It is assessed when a member of the defending team spends more than three seconds in the free throw lane (also known as the 16-foot lane, or colloquially as "in the paint") while not actively guarding an opponent. To be considered actively guarding, a defender must be within arm's length of an opponent and in a guarding position.[1] A three second count is suspended if:[2]
In addition, a player guarding an opponent with the ball may be in the paint without actively guarding the opponent.[3]
The team committing a defensive three-second violation is assessed a team technical foul. The offense will receive one free throw and retains possession of the ball.[4]
Previously, any form of zone defense was considered an illegal defense violation and resulted in a warning on the first violation and then a technical free throw for any subsequent violations. In the spring of 2001 the rule was changed to its current form as part of an initiative to speed up play in the NBA.[5] The high school and college game do not use this rule.