Before wicked fun games like Oblivion and Fallout existed, my brothers and I used to play Dungeons & Dragons. And before any of us could go dungeoning we had to create our character, and one of the most important aspects of the creation was deciding alignment:
Lawful Good is known as the "Saintly" or "Crusader" alignment. A Lawful Good character typically acts with compassion, and always with honor and a sense of duty. A Lawful Good nation would consist of a well-organized government that works for the benefit of its citizens. Lawful Good characters may sometimes find themselves faced with the dilemma of whether to obey law or good when the two conflict - for example, upholding a sworn oath when it would lead innocents to come to harm - or conflicts between two orders, such as between their religious law and the law of the local ruler. Indiana Jones is a lawful good character.
Neutral Good is known as the "Benefactor" alignment. A Neutral Good character is guided by his conscience and typically acts altruistically, without regard for or against Lawful precepts such as rules or tradition. A Neutral Good character has no problems with co-operating with lawful officials, but does not feel beholden to them. In the event that doing the right thing requires the bending or breaking of rules, they do not suffer the same inner conflict that a Lawful Good character would. Spiderman is a neutral good character.
Chaotic Good is known as the "Beatific," "Rebel," or "Cynic" alignment. A Chaotic Good character favors change for a greater good, disdains bureaucratic organizations that get in the way of social improvement, and places a high value on personal freedom, not only for oneself, but for others as well. They always intend to do the right thing, but their methods are generally disorganised and often out of alignment with the rest of society. They may create conflict in a team if they feel they are being pushed around, and often view extensive organisation and planning as pointless, preferring to improvise. Starbuck from Battlestar Galactica is a chaotic good character as is Robin Hood.*
tomorrow: alignment - part 2 - neutral