Is karate a good self-defense system to learn?

Depends, depends on the mind-set and expertise of the sensei. What I mean is that most martial arts taught in the west, and more so in the east now as well, are sport oriented or philosophy oriented systems. They are good for what they are meant for but as to self-defense they often don't provide more than "a false sense of security."

With all the physical stuff in today's karate along with the sides-show physics oriented practices such as breaking boards and bricks it can give one the sense that what they are doing is effective, dangerous and applicable to defense. This is simply not true but for a few dojo.

Even those who attempt to practice a more fighting, defensive or combative system still have to live under rules, rules mean hindrances against realism, realistic violent conflicts. When you place rules in the picture the picture becomes a caricature of the real thing.

Now, some sobering information. You will in all likelihood experience more violence and injuries in a marital art system than in real life defensive situations. It is just a fact. A month did not go by in my first five years of training, practice and teaching that I didn't get hurt, i.e. a broken tooth, a cracked rib and the times I broke toes just is not worth counting/tracking. Then there were the bruises, shin scrapes, bruised bones, etc. and that was with some form of protective gear.

Karate is a medium that promotes healthier bodies and minds. If taught as intended it is truly a way of things, a "Do" if you will. It can provide some ability to defend yourself provided it is coupled with all the knowledge and understanding of self-defense law and all those other things associated with self-defense situations - in a limited way, i.e. a social monkey dance encounter. But beware, remain aware, the law is fluid as to self-defense and there is so much more here than is taught in most training facilities.

If your need is for self-defense keep in mind all this and that the statistics state that most folks will never, ever encounter true violence in their entire lives - do you really need it or is it you need "a sense of security" that comes with taking marital arts and/or self-defense instructions.

You got to ask yourself all these questions; you got to asses and analysis your needs for this stuff; you got to know what it is you have and don't have - it is more important than signing up for classes that may or may not give you what you need, not necessarily what you think you want.

Try this, if you feel your martial art is adequate for self defense then truly test this out. How? Find a seminar for either, or, or both Rory Miller and Marc MacYoung and discover the answer for yourself.

Note: not an endorsement for either Mr. Miller or Mr. MacYoung but they are the primary folks I find for my perceptions as a litmus test for reality in self-defense. Try them out and see for yourself.