The clearest thing about the Book of Judges is that, "In those days there was no king in Israel: every man did that which was right in his own eyes." (21:25) That is repeated several times in this book. After Joshua dies, there's a long period in the promised land wherein the twelve tribes of the descendants of Jacob (Israel) keep turning away from God's rules and need some judge to step in and set them right.
The story of Jephthah, the guy who made a stupid promise to God, is just sad. He says to God, I'll sacrifice whatever is the first thing out of my front door when I get home if you'll let me take out our enemies the Ammonites. He's assuming it'll be a chicken or a goat, I guess, but it's his daughter, his only child, who runs out to greet him when he gets back. He feels awful about it, but a promise is a promise. Even his daughter recognizes the seriousness of breaking a promise to God, so she doesn't put up a fuss, but allows herself to be killed by her dad. Tough stuff. Lesson: don't make stupid promises you won't want to keep.
Deborah is a judge who is also a warrior. The feminist in me delights in the fact that a woman is finally not just a pawn in the terrible games men play in the Old Testament. When Barak, the Israelite military leader, asks her to go into battle with him, she prophesies triumph against Jabin, the Canaanite King of Hazor, but says it will be a woman who will be remembered for the victory. Yep. A woman. Not her though, but a woman called Jael who tricks a Canaanite guy (Sisera) into coming into her tent for a rest and then while he's sleeping drives a tent peg through his skull. More graphic violence, but at least this time it's a woman doing some damage instead of passively allowing herself to be subjected to the idiocy of the men around her.
In FACT, the best story in Judges (IMHO) is the story of Samson and Delilah, in which a woman again defeats a man (well, in the short term, at least). Samson's this guy who's holy right from the moment he's conceived, and his power comes from his hair, so he never gets a haircut. I'm picturing a middle-eastern Fabio. About as dumb, too, it seems. One day he falls in love with this Philistine (read = enemy) woman called Delilah, who keeps trying to get him to tell her the secret of his power so her crew of Philistine thugs can kill him. He keeps lying to her, and each time the thugs try to take him out they fail. Finally, however, he gives in and decides he loves her so much it's worth revealing the truth, that if his hair's cut off they'll be able to overpower him. And just like that, he falls asleep on her lap (idiot) and they come in and shave him bald, tie him up, pluck out his eyes (I'd say this is overkill) and take him away to their palace where they proceed to party. BUT, he makes a promise to God that if He gives him his strength back, he will avenge His people (the Israelites). A bit of his hair's grown back by this point anyway, so when he pulls on his chains, which are tied to the pillars in the palace, the whole place comes crashing down, killing everybody, including him. So everybody dies in the end. Wow. I have no idea what the lesson is here, but at least it's got intrigue and a good narrative arc.
So that's Judges. There was a bunch of other stuff going on, of course; mostly Israelites worshipping other gods (who ARE these other gods?) and needing to be set back on course. There's lots of battles against other nations, and a whole bit about Benjamin (an Israelite tribe) going off the rails and needing to be taken out. But then everyone decides the Benjamites need to be built back up again so they go and get them some Philistine virgins to repopulate their tribe.
I'm glad I didn't live back in those days. It was all vengeance, violence, burnt offerings and raping of virgins. I'm also glad I wasn't on the wrong team. If you weren't an Israelite, who were you? Nobody. And you needed to be dead. My God can beat up your God, and all that.