An unarmed self-defense technique advised by the SAS (Special Air Service). Although brutal, it is highly effective, and will take down almost any assailant. Personally, I'd rather be armed than unarmed if I'm caught in a situation like this. Screw gun control. In any case, here it is.
  1. Since most people are right-handed, their first attack is likely to a right-handed punch. Block it with your left arm. If the attacker is left-handed, reverse the left-rights in this sequence of moves.
  2. Continuing the blocking motion of your left arm, continue with a two-finger jab to the eyes. Although this is a very brutal move, it is extremely important to throw the attacker off balance and hence allow you to follow up with the rest of the sequence, and this does an excellent job. Anyways, better him than you.
  3. The last move should have left the attacker wide open. Follow up with a right-handed palm strike to the chin. This should put the attacker on the ground and convince him to leave.
  4. If the person is still unconvinced, step forward with your left leg, swing your body around, lean in and strike with your left elbow on the chin or face. Use your hips to maximize the force of the attack. This usually guarantees a knockout.
  5. If somehow the person is still acting hostile, step in, grab his shoulders, and knee him in the groin as hard as you can. At this point, you can simply walk away.
This technique has been tried and tested. However, hesitation at any step would ruin the sequence and open you to attack. Admittedly, some of these moves are very violent, but it is self-defense, after all. Practice it and make it one fluid motion. It will discourage any attacker.