Alignment is a character’s orientation on a cosmic scale. It has nothing to do with a character’s allegiances, personality, morality, or actions. Alignments will mostly be used to determine how a character is affected by certain magical elements in the game. The three alignments are Lawful, Neutral, and Chaotic.
The universe has an ultimate, irrefutable truth, and a flawless, unchanging plan towards which all events inevitably march. [...] Those who are Lawful in alignment are part of an inevitable destiny, but have no knowledge of what that destiny is and what their role will be in fulfilling it. [...]
The howling maelstrom beyond the veil of shadows and existence is the source of all magic. It bends and tears the fabric of the universe; it destroys all that seeks to be permanent. [...] Those who are Chaotic in alignment are touched by magic, and consider the world in terms of ebbing and flowing energy, of eternal tides washing away the sand castles that great kings and mighty gods build for themselves. Many mortals who are so aligned desperately wish they were not.
To be Neutral is merely to exist between the forces of Law and Chaos. [...] Even most who would claim allegiance to Law or Chaos are not actually Lawful or Chaotic. In the real world, every human being that has ever existed has been Neutral.
Clerics must be Lawful. Elves and Magic-Users must be Chaotic. All others are free to choose their alignment.