During the 1983 season, when the NBA was in the midst of the sale of the Cleveland Cavaliers, the NBA had to compensate the team by awarding them draft picks to interest potential bidders as the Cavaliers had traded away so many future first-round picks already.
As a result, the NBA created the Ted Stepien Rule, named after the Cavaliers owner at the time. The rule stated that no team can participate in trades that would leave them without first-round picks in back-to-back drafts.
However, teams found a loophole around this, as they often do in the NBA.