What is Alignment?
If you're new to AD&D, you may have wondered what the heck alignment is. Unfortunately, too many experienced players don't have a clue, either. (In my opinion, this is partly due to the fact that both the Player's Hanbook and DM's Guide describe alignment very poorly).
Alignment can be described as your character's world view - what kind of moral stands he takes, and how much he lives "by the book". This is a very useful tool in roleplaying... but many players (and DMs) don't understand it, and alignment either ends up being ignored, or being viewed as a hindrance. If you select your alignment carefully when creating a character, it can help in defining and developing your character.
There are nine distinct alignments in AD&D. They are:
Lawful Good (sometimes refered to as Lawful Stupid): LG characters bellieve that justice and right are best advanced through the firm rule of law. A holy crusader is an example of this.
Neutral Good: NG characters are for goodness, but stand more for the spirit than the letter of the law. They are apt to judge each situation on it's own particular merit.
Chaotic Good: CG characters have a strong moral compass, but don't want anyone telling them what to do. They often view laws as petty and restrictive, and tend do do what they feel is right regardless of the consequences.
Lawful Neutral: LN characters thrive on order and regulation. Consider the judges from the movie "Judge Dredd", and you have LN.
True Neutral: TN characters seek balance in all things. This is an alignment often attempted, and seldom pulled off, by many players. A good example of TN is the mage who studies magic for the sake of the knowledge itself.
Chaotic Neutral: CN characters often act on pure whim. While the Player's Handbook describes them as insane, my take is that a CN character is one that looks out for #1 at all costs... but isn't as morally depraved as a chaotic evil character, either.
Lawful Evil: LE characters seek to further their own goals (at the expense of anyone else), but do so with dilligent planning and discipline. A general who systematically excecutes all of the men in a captured city to prevent resistance is an excellent example of this.
Neutral Evil: NE characters are masters of situational ethics, seeking protection of the law if it benefits them, skirting it if it does not.
Chaotic Evil: CE characters are the most despicable in existance. They often kill, torture, and rape for the joy they gain from it, and no other reason. A chaotic evil character will cheerfully slit your throat while you sleep in order to take your last 5 silver coins.
Thanks to t_catt11 for this contribution!