Let's start with five critical points. Points that trump anything you think you know about self-defense and the 'law.'

#1 - This is NOT legal advice (you get that from an attorney), but it is about a major hole in most so-called 'self-defense' training.
This hub is to acquaint you with issues you have to be prepared to face if you use your training (including why having an attorney is critical). Run through the next four points and see how many were covered in you training. You should know, if left un-addressed, these issues will result in you sitting in cell for 'defending yourself.'

#2 - There is a difference between the law and the legal system
The law says you have the 'right' to defend yourself. Great, that and two bucks will get you a cup of coffee. The legal, system is strongly influenced by politics, careerism, finances (including revenue generation, funding and budgets), pressure from higher ups, plea deals, cost analysis, lawyering loopholes, and let's face it, human error, selfishness and bias. If someone in the legal system decides you were 'in the wrong' they are going to use the law to try to convict you. After you defend yourself, you have to be prepared to defend your actions on this front. Too many people in training focus on the event, not the aftermath. That's why they end up convicted. This is how things are, suck it up and prepare yourself to deal with it. Otherwise, you're going to get crushed by the legal system -- even if you acted inside the law.

#3 - Ours is not a justice system, it's a legal system.
This is one of the hardest things for good people to get their heads around. It's not about what's right, wrong, fair or just; it's about what the law says --including what is considered the bigger crime. Yes the law says you can defend yourself, but it also has a lot to say about violence against your fellow citizens being illegal (except under specific conditions). Which brings us to...

# 4 - Self-defense is a legally defined term.
Some years ago I watched a commercial martial arts instructor teach a military style neck break on a downed and helpless opponent, from behind. He saw my horrified and quickly added "This is only for self-defense." Which appalled me even more. Anybody who performed that technique thinking it was 'self-defense' would be on a fast track to a manslaughter conviction -- if not murder. Do you know why?
It is very important for you to flush down the toilet anything you've heard about 'what is self-defense' from martial arts teachers, combatives instructors and the internet. Those aren't the standards your actions will be judged by. Also, it doesn't matter what you felt or believed you were doing. What matters is what you actually did. (For example, leaving your property, going to someone's house to confront them and then claiming self-defense -- isn't going to fly.)

#5 - If you claim self-defense you are confessing a crime. (Well technically you're confessing to the elements of a crime.)
Self defense is what is known as an affirmative defense. You just said, "I did it." Hurting your fellow citizens is overwhelmingly a crime. The exceptions require both specialized circumstances AND the ability to explain, to legally accepted standards, why you were acting within the allowed exceptions. So with your confession, you have to prove why it was one of these exceptions. 
That means -- among other things -- explain why the situation required force and why you reasonably believed you had no viable alternative.
How good at recognizing these circumstances are you? How about explaining them? What about answering why you didn't just turn and walk away? Have you practiced? That's what it takes when you claim self-defense. If you cannot do these, then you are going to be held accountable to the crime you just confessed doing.

So how'd you do? If those points are news to you, you might want to get a cup of coffee and spend some time here.

When It Isn't Self-Defense
Simply stated: Self-defense is legal, fighting isn't. Neither is assault and battery or excessive force.

An overwhelming majority of physical violence is -- in someway -- illegal. This is over and above someone in the system looking for an excuse to charge and convict you.

Usually people don't get arrested for defending themselves; they get arrested for committing illegal violence while telling themselves they are defending themselves. Even if it starts as self-defense, all it takes is one extra hit, one impulsive move or one excessive trigger pull for you to cross the line from a defender to an attacker.

Issues like pride, fear, anger and bad information are far more dangerous to you than the person you are fighting with. They will motivate you to cross the line while, at the same time, convincing you that you are 'defending' yourself.

There are serious legal (as well as life-altering) issues about using force on another human being. Before you listen to someone who wants to teach you how to shoot, stab or commando ninja someone, realize that person can be putting you in just as much danger as a potential attacker. You had better know the differences between violence, self-defense, fighting and justified use of force.

I have a saying: I am constantly approached by people who are willing to go to any extreme for personal safety ... except practicing emotional self-control. This not only includes not letting your fear drive you to pulling the trigger, stabbing someone or unleashing your deadly kung fu on someone because of 'fear,' but one's participation, creation and escalation of a conflict. This includes not only what you said and did to get the other person to back off, but your refusal to just walk away. This is critical because usually, violence comes with instructions how to avoid it

Except, often pride, anger, fear and imagination prompt us to do exactly the opposite. When this occurs the violence is considered participatory (fighting). Even though our internal reality is that we are trying to prevent violence.

Reality doesn't conform to what you think a 'real fight' is, you must conform to the actualities of what violence is, how and why it occurs. And that means what happens before, during and after. All of which extend far, far beyond the microscopic focus of martial arts, reality based fighting systems or women's self-defense programs. If you participated in the creation, escalation and gave cause for violence, then you will be judged to be a participant, not a victim of violence.

Do your homework
My attorney Paul Spiegal has a saying, "Everyone knows what something means until there is a problem."

This is a very accurate and wise summation of a generalized problem about communication. The reason is typically each of us have our own -- often unconscious -- definitions and implications of words. Although there is often general agreement, we all have our own 'spin,' personal shadings, connotations and definition about what a word means. And we often act according to that private version.

So what you have is a lot of people using the same word, but each meaning something slightly different. When a problem develops, everyone is wondering "what is wrong with the other person". Not realizing that source of the problem is that they have different definitions of the same word and were each acting according to their own definitions. Overcoming these kind of problems is a major focus of communication and management specialists.

Having said this about fuzzy definitions in general, there are NO gray areas in the meaning of legal terms.

They are very specific and exact in what they mean. And what they mean legally ISN'T what they mean to you. For hundreds of years these words have been hammered out and defined as people have tried to weasel around them.

As such, it doesn't matter what you think the word means, you will be judged by these established legal definitions. It is up to you to know the definitions of these words and tailor your actions accordingly. That's because just one or two ill chosen words will totally blow your claim of self-defense out of the water.

We recommend taking a tour of the legal definitions presented at the 'Lectric Law Library, read Introduction to Use of Force and consult with an attorney before you even think of using what you know in an actual encounter. While you're at it, check your state AND local statutes and consult with your attorney before engaging in what you think is 'self-defense.'

Quite simply most people's definition of 'self-defense' is looked upon by the law as fighting (consensual combat -- look that up too). As such you will be arrested and charged IF you were fighting instead of defending yourself. Also, take a look at the 'Lectric Law Library's outline of the common legal interpretation of self-defense, then compare local interpretation and caveats.

Pay close attention to the "mutual combat" and "quarrel" clauses in your state's law. As these subtly phrased, but very important clauses, can and will destroy any chance you have of claiming it was "self-defense" if the incident report is written up along these lines. No matter how justified or 'set upon' you felt you were, that report is a legal document and will be the source of all legal action.

If you are thinking of owning, much less carrying any kind of weapon (especially a gun or knife) we recommend you look into the services and training provided by the Armed Citizens Legal Defense Network. Followed by Masaad Ayoob's, Judicious Use of Lethal Force seminar. If nothing else then get to a US Law Shield class in your area. Do this BEFORE you ever pick up that weapon in self-defense.

You will not learn this information in a martial art school. Remember, weapons are like power tools, mistakes happen much faster and are far nastier.

We recommend you look into the sections on use of lethal force, understand the difference between fighting and self-defense, as well as acquaint yourself to the issues surrounding home defense.

Going to Jail for 'Defending Yourself'
After physical injury there is no concern greater to people looking into self-defense than the chance being arrested for 'defending myself.' It's a legitimate concern. In fact, it's probably one of the most rational and realistic concerns when it comes to the issue of self-defense.

Unfortunately most of the answers coming from the self-defense/martial arts trainers aren't just out in left field, they're over the fence and out in the weeds.

There are several overlapping issues that contribute to this whole morass. We take a look at the idea of going to Jail For Defending Yourself

Home Invasion
Although technically not a legal issue, home invasions are the most dangerous of circumstances -- whether the goal is robbery, rape or muder. This page will put into perspective many of the issues involved in deciding to use lethal force. It's framed in the terms of home invasion but you'll see many issues about immediate threat and reasonably believes.

Home Defense
Should you have a gun in the house? We're not going to tell you yes or no. But we will discuss issues involved in Home Defense so you can make an informed decision.

Lethal Force
Most people do not understand the standards surrounding the use l ethal force. Nor do they understand that this also applies to the use of a lethal force instrument -- even if you don't kill the person.

Postive and Negative 'Rights'
Often the problem isn't with the original idea, but how people decide to take an idea and run with it. Postive and Negative rights is an idea that people haven't just grabbed and run with down the street; many were was last seen crossing the state line (with how far they take it). Oddly enough, most people haven't even heard of the idea. This even as they are being abused by someone who's twisted this controversial interpretation of rights. You've seen the idea of Positive and Negative Rights twisted if you've ever run into any of the following:
"I have the right to_____. But you don't have the right to _____" ,
"I don't have to ____, but you have to____",
" _______ (someone else's service or property) is a human right," or
"I shouldn't have to _________."
And of course, "You can't tell me what to do."
These twisted interpretations of rights are a growing attitude in this society. One that get's people into conflict as more and more people believe it's their 'right' to _____. It's also an attitude that can get you beaten, killed, raped or arrested if you try on act on the idea.

Self-Defense Explained
This isn't legal advice. Legal advice is what you need AFTER you've found yourself in hot water. This introduction to what self-defense is is what you need to stay out of hot water. Self-Defense explained is a layman's explanation on how NOT to cross the line from self-defense into assault.

Using Your Martial Art to Defend Yourself
This is an excerpt form our book specifically addressing Using your martial arts to 'defend' yourself.

What Is Viewed As Participation
The title of this page is Best Ways To Get Attacked. These fundamental points are how most people make mistakes that evoke a physically violent response. When you're adrenalized, scared and angry it is VERY easy to give into these impulses. More than just their ability to escalate a situation to violence, investigators (and witnesses) will be seeing these actions as your willing participation in the creation, escalation and execution of violence.

Testifying in court
Was it self-defense? NNSD offers expert witness service to attorneys with violence reconstruction.