SACRAMENTO — California on Monday will launch some of the most sweeping changes in sentencing laws over the past four decades as the state shifts significant criminal justice responsibilities to the counties and courts.

But some judges and lawyers say they’re embarking upon this historic prison realignment without a very good road map. As late as two weeks ago, the state was still tweaking rules and procedures, leaving courts, prosecutors, public defenders and law enforcement agencies scrambling to study the changes and to create a new system that will work when courthouse doors open Monday. The Judicial Council is still crafting new rules to guide judges.