Judges tells of the leaders of Israel between Joshua and the beginning of the monarchy, a period of three to four hundred years. There is a recurring cycle at this time in the life of Israel: sin, domination by a foreign power, repentance on the part of Israel, and finally, God raises up a judge who delivers Israel from foreign domination. A time of peace and prosperity followed before the cycle was repeated all over again - apostasy, oppression, repentance, deliverance. It happened at least seven times.
There were at least 14 judges, with six major judges: Othniel, Ehud, Deborah, Gideon, Jephthah and Samson.
This period in the life of Israel is characterized by unfaithfulness to God and general spiritual decline. It is described in the last verse of the book: "In those days Israel had no king; everyone did as he saw fit." (Judges 21:25)
After a period of seven years of cruel Midian dominance, God raised up Gideon to deliver Israel. Gideon had a huge inferiority complex. Nevertheless, God chose him and used him to bring about a mighty victory.
Samson didn't so much deliver Israel from Philistine harassment as he did check Philistia from doing all she would have. The interesting thing about Samson was his personal failures and the opportunity for a second chance.