Depending on the training program, and how well a person is progressing, could be just a few weeks, could be a few months to a year. Just depends on the person. Also, no defense is a certainty against an unknown attacker, so this is just "best guess". I personally could have defender myself against an attacker with anything less than a gun withint about 6 months.

I would say that you could defend yourself against a mugger without using any karate, as long as you know basic self-defense. I don't know much about karate, but if I am right it takes a loong time in study before you learn practical moves and real-life defense so probably a year? The best practice though (unless you are Chuck Norris or Jackie Chan) is to just throw your wallet one way and run the other!!!

IMO it depends on the type of Karate you do. (i don;t mean style). if you do the type here they focus on tournements and winning trophies then i think it would take a while, most of the disabling moves are banned. if you do a type of karate where they don;t have tournements and focus on real practical fighting then you learn to defend yourself from the first lesson. well thats what i get from my experience with martial arts.

It depends on you, and if you've been learning by tournament rules or street moves. If it's mostly tournament rules, it'll be longer than with street moves, and hopefully you won't unconsciously assume that your opponent is going to abide by the rules. That said, I've seen beginner guys who could defend themselves well, and long-time students who wouldn't have had much of a clue. If it's street-style defense, it will also depend on the student, and the more you've studied the better you'll be. If she has a gun, of course give her your wallet. (I'm trying to be non-sexist in my use of pronouns.) If she has a knife, give her your wallet anyway. Hopefully you won't know just enough to make you think you can fight for your money, and get stabbed.

That all depends on what weapons are involved, size, strength, speed, coordination (of both the mugger and the defender), and the location, terrain, surroundings. It is possible that a clumsy untrained person could defeat an even clumsier drunken stumbling mugger who does not really know what he is doing ... it is also possible that after several decades of training every day and reaching a high level (such as my 7th Dan) that the mugger could be the winner. There are far too many unknown variables within your question for an easy simple answer ... but any "intermediate level" or above should have sufficient skills, knowledge of techniques, and confidence to at least risk attempting to resist a mugger with only a knife, chain, pipe/stick, etc., but not a handgun or sawed off shotgun.

The best defence is to give the mugger what he wants and run like hell. If he's got a knife, you're in big trouble if you decide to "defend" yourself and resist him. Only resist a knife weilder if there is no other choice. Knife defence is very difficult, perhaps the most difficult skill to "master". A good hour of knife training will trump a large degree of skill in any unarmed martial art, case closed. Even if you are successful, you're going to get cut or worse 9 times out of 10. Remember that 60% of stabbings are fatal. If you want to understand weapons, then you have to train WITH them, not only against them. So the answer is, IMO: If he's unarmed, then a good year of SOLID training should give you a pretty decent chance. If he's armed, then it takes years and years, and even then you're not guaranteed to survive at all.

That all depends upon the person. I am a first degree black belt in Tae Kwon Do, and I believe that only just now, after over four years of study, could I defend myself. However, I would stress that an effective technique is one that you can deliver simply, directly and without much forethought. What I mean is, even though I know many different kicks (as is the primary focus of Tae Kwon Do), I would probably use a basic one in a self-defense situation. Palm strike, front kick, side kick, knife-hand; all of these are ones I would consider. Linear, fast and powerful. However, I would probably stay away from , for example, a back roundhouse kick or turning front roundhouse kick. In fact, I might avoid a kick altogether; my upper-body strength is pretty good. My wife, on the other hand, (who is also a first degree black belt), could kick much more effectively that I could. She would probably be better off using her feet, because her legs are very strong and she can kick high to someone's head. So a person's gender is of some concern as well. My instructor, a Grand Master (9th degree) could certainly use advanced kicking techniques, but his delivery is exponentially faster than mine. I would say that, if you are reasonably fit, coordinated and can mantain a cool head in a very stressful situation, you could know enough at an intermediate belt level to defend yourself. I say a cool head because all the training in the world is not going to help you if you panic or freeze at the moment of truth.

None, jam your fingers into their eyes.

Quite a bit really, because you have to learn how to block properly, and use differant hand techniques to strike. So Karate is only effective in the long term. Martial Arts was never meant to learn quickly, it is a long continual process that teaches you strength and discipline. However, the rewards of sticking to it pay of in the end.

It depends on your abilitys, your school and where the main focus of you training is while in class, If you are in a sport rec. system you will whve a problem. No matter the skill level however thee best action is to run away if possible. using your art is the very last thing you want to have to do. when you cannot run away they you use all your skill and pray that it is enough to get you through.