Baby, you have no need to be scared of me...I promise that I'm not a mistake...
We are all selfish and we are all mostly self-centered. Yet, when it reaches clinical level of NPD it often goes untreated and so we are left to our devices when we find ourselves matched with a clinical narcissist and we are often outmatched from their guiles, their charm, their excellent manipulation tactics, and most importantly their intense desire to have others worship them.
You can research what a narcissist is but what in real terms of dating would help to understand when there's a narcissitic wolf waiting to gobble up your self esteem and break you into worshipping them?
THE INJURED EGO
First, to catch a narcissist one must understand a narcissist. A Narcissist often has a parent or parents that both were narcissists themselves. Furthermore, parents can commit conciously or unconciously what's called a "narcissistic injury" on their children in a variety of ways including overly praising their children to give them unbalanced sense of their own power and importance in the world. Othertimes, it's insulting the child mercilessly that the child creates a False Self in order to compensate for the injured self esteem. Think "my dad/mom won't love me so I'll love myself extra big." Obviously, different types of injuries will create different types of narcissists. More on that later.
THE DIFFERENCE BETWEEN A NARCISSIST AND A SOCIOPATH
A narcissist isn't as calm a character as sociopath. They suffer from an incredible desire to be praised and to be important, but they aren't without emotion and feelings and in fact are often plagued with feelings of jealousy if they don't get their way. A sociopath by comparison feels nothing and has to "fake" feelings so that others don't realize what the sociopath is. Both are forced to hide in plain site but think about how this would go...the sociopath would be a great hider. No matter what he or she would convince the others that he/she was one of them. The narcissist couldn't resist telling the others that he was better. He or she can't resist but to proclaim that they are a wolf gobbling up sheep and so narcissism always reveals itself eventually.
HOW THEY BASICALLY OPERATE IN RELATIONSHIPS
So many people are extremely selfish. What makes a narcissist so scary? Well, he or she doesn't really see people as people at all...they see them more like lifeblood or wells of water. In order for the narcissist to survive in the narcisissistic state they have to have "proof" of their greatness and in order to get this proof or "to drink" they have to have other beholden to them...worshipping them, praising and doing nice things which prove how great the narcissist is. In general, this gives the narcissist ambition to develop very charming social skills, which depsite most thinking can in fact be learned even if you don't start out with them. If they are not charming, they find other ways of manipulating others to become dependent on them. Dependence for a wolf like a narcissist is the ultimate guarantee that they are in control that this person will continue to praise insofar as they will never leave. This is how you can make a strong argument that the alchoholics wife is often a narcissist herself because she commited to a man who can never really leave her even if he cheats because he will never be strong enough to want to leave her. Furthermore, she can make others feel sympathy for her as the wife of an alcoholic and the cross he must bear because of it which she does because she's just so loving. And this is the genius of the narcissist at work. They are in control, they have others beholden, and they are generally invulnerable from being hurt themselves except for when people leave them but even then they usually have such a strong grip on them they can bring them back and if not they see people as wells of water and therefore replaceable. It's always the hunt for more and no one person can make the narcissist happy.
I'll just go into the two main ones though there are many branches.
The alpha narcissst is the classic. He or she will have grandios images of themselves and not understand why others can't seem to understand their godlike greatness. Many guys pretend to be actual narcissists, but if their family was drowning a true narcissist would save himself without even thinking about his own mother father or siblings. They are truly so in love with themselves that all others are excluded permanently. They lack an understanding or an ability why other people should matter and experience incredibly low level of remorse for things they do in service themselves that have grave affects on others. While a sociopath sees a human life as a human life but doesn't understand why killing that human life is wrong, the narcissist gets why it's wrong, but doesn't care so long as it's not his/her own. They attend funerals and find they feel nothing which probably scares them a bit as well.
The secret narcissist is probably more common but less classic because they don't as often reach positions of greatness. He or she was probably made to serve their narcissistic parent in someway...think the son who had to provide emotional support to his mother who is father emotionally abused when he was only 5. They see themselves violated and so create many negative defense mechanisms and secretly want to overcompensate for that pain with soemone who loves them not only unconditionally but more as object than a person or in other words worships them. what this looks like is constant jealousy and paranoia that you are cheating or planning to cheat on them. If you don't give them all of you, you're giving them none of you. They use guilt as their weapon of choice. They are insecure where the classic narcissist is oversecure. As such, they are usually a lot less seductive and attractive people. The secret narcissist probably complains that no one will ever love him/her the "right way" (they mean worship not love) and is probably secretly envious of the alpha narcissist's charm and self love but feel that without the love of someone else to sponge self love off of they are not deserving of charm and confidence.
WHO ARE THE VICTIMS
The victims are people who aren't happy with themselves and with their lives. The narcissist has to have room to manuever and is often invasive into someone else's life as he/she inserts themselves prominently and sets up a system of dependence. People who are lacking something whether it's money, love, or safety are temporarily given these things by the narcissist who then uses their dependence to manipuate them into forced love. Think God could easily have stopped adam and eve from eating the forbidden fruit but gave them a choice...a real narcissist isn't interested in such a choie. They want to be wanted but not to genuinly want others.