How Does One Judge What is Right and What is Wrong?

Definitely, the effects of ones actions can be seen and one can infer from that if what they did was good or bad. but there's just one little snag. Some people think they are doing the right thing even when they see the catastrophe caused by their actions.
The Nazis saw the evil they were doing but they still thought they were right, that they were cleansing the unclean race from the face of the earth.
This goes to show that their conscience was warped and they had the belief that the crimes they were perpetrating were for the common good of their race.
When I said Conscience, I meant for normal people, like you and I, not for prople who think they have a right to play King of all.

Ok, I gues those theories Utilitarianism and reciprocity are better than Conscience then.
I concede.

con·science (knshns)
n.
The part of the superego that judges the ethical nature of one's actions and thoughts and then transmits such determinations to the ego for consideration.

@nferyn
I do not think utilitarianism leads to conscience. Conscience is individualistic while utilarianism is the accepted norm by d majority. People conscience oppose at times. You strongly believe there is no God but i also passionately believe there is GOD. We cant both be right. I wouldnt think conscience is strong enough to determine what is wrong or right.

Your definition is a rather Freudian one, I must say. And Freud's view on psychology has been thoroughly refuted by modern psychology.
Utilistarianism is the principle by which one decides what the utility of an action is. Utility is then defined as I did. It's not really the norm of society.

My conscience is determined by applying those principles of utilitarianism and reciprocity. That's what defines it.
Somebody elses conscience may very well be totaly instinctual, it all depends from person to person

And actually, I do not strongly believe that there is no God, I'm an agnostic atheist, not a gnostic one (meaning that I have no knowledge of wheter or not here is a God, but that I do not believe there to be a God) In the absence of evidence (and not the evidence of absence, you cannot possibly disprove God) I take the position not to believe.