The book of Judges serves to show that a theocratic people need a righteous king. Without a king who reigns under the special authority of God, confusion follows – Every man did that which is right in his own eyes. The book thus has a negative purpose. When the people are without a ruler, there must be awakened within them longings and aspirations after a true king. During the period of the judges, the people are gradually brought to see their need for a king.
The book derives its name from the rulers – “judges” (shophetim), who ruled over Israel during the period between Joshua and Samuel. These were not, however, merely civil magistrates who administered justice and adjudicated disputes. Primarily, they were deliverers (lit. “saviors,” moshe‛im), endued with the power of the spirit of God, who were called upon to deliver and to govern the people in times of decline and oppression.
E. J. Young. Introduction to the Old Testament. “Judges” 170.