Not all circumstances are the same, but if you're accosted you should know the odds of getting out alive lessen in certain situations. Thwart attackers by having a defensive plan. The first thing you can do to fight back is not to become a victim in the first place.
Don't go out alone at night.
Don't go to places that are deserted or dangerous.
Pay attention to what's going on around you.
If you do stumble into a situation, how can you raise the chances of coming out alive?
* The number one rule of surviving an attack is to never, ever allow your attacker to transport you to a secondary crime scene. People who climb into cars with their attackers are almost always killed.
* What if he has a gun or a knife? If he's trying to force you into a car or building, then fight. Yes, you may be injured, but if you go with him, you will die. Your odds of living are better if you run, and if you can't do that, stand and fight.
* Raise as much of a ruckus as you can. Scream. Yell. Pound on things that make noise. Attract attention by any means at your disposal.
* About running -- if you can get away keep running. Don't stop until you find other people. Yell the word "Fire!" Others will investigate.
* Give him your wallet, purse or other valuables if he asks for them. They can be replaced. You can't.
Cops know that the victim most likely to survive is the one who doesn't give up.