Law (or Lawful) is the belief that everything should follow an order, and that obeying rules is the natural way of life. Lawful creatures will try to tell the truth, obey laws, and care about all living things. Lawful characters try to keep their promises. They will try to obey laws as long as such laws are fair and just. If a choice must be made between the benefit of a group or an individual, a Lawful character will usually choose the group. Sometimes individual freedoms must be given up for the good of the group. Lawful characters and monsters often act in predictable ways. Lawful behavior is usually the same as behavior that could be called "good".
Law implies honor, trustworthiness, obedience to authority, and reliability. On the downside, lawfulness can include closed-mindedness, reactionary adherence to tradition, judgmentalness, and a lack of adaptability. Those who consciously promote lawfulness say that only lawful behavior creates a society in which people can depend on each other and make the right decisions in full confidence that others will act as they should.
Chaos (or Chaotic) is the opposite of Law. It is the belief that life is random, and that chance and luck rule the world. Everything happens by accident, and nothing can be predicted. Laws are made to be broken, as long as a person can get away with it. It is not important to keep promises, and lying and telling the truth are both useful. To a Chaotic creature, the individual is the most important of all things. Selfishness is the normal way of life, and the group is not important. Chaotics often act on sudden desires and whims. They cannot be trusted, and their behavior is hard to predict. They have a strong belief in the power of luck. Chaotic behavior is usually the same as behavior that could be called "evil".
Chaos implies freedom, adaptability, and flexibility. On the downside, chaos can include recklessness, resentment toward legitimate authority, arbitrary...