For the second time in his storied N.B.A. career, Jason Kidd has been asked to play savior for the Nets, a franchise that has been moved and transformed but is forever seeking credibility.

The Nets signed Kidd as their coach on Wednesday, banking that his basketball acumen and his Hall of Fame credentials can lift them into championship contention, despite his lack of coaching experience.

It was a stunning and unconventional move. Kidd, 40, just retired as a player on June 3, after one season with the rival Knicks. Although many former players have become successful head coaches without first serving as an assistant, few have gone straight from playing to coaching so quickly.

“Jason is a proven winner and leader with an incredible wealth of basketball knowledge and experience,” General Manager Billy King said in a statement. “This will be a natural transition for him to move into the role of head coach, as he embodies the tough, smart and team-first mentality that we are trying to establish in Brooklyn.”