I think a topic like this may have been brought up once before, but... new edition, new chances, yes? The 4th edition of Dungeons and Dragons uses a much simplified alignment system, as opposed to the Law/Chaos and Good/Evil axis of prior editions. I'm morbidly curious about what characters in Ranma 1/2 could be considered to express which alignment, so...
For myself, I wouldn't call any character Lawful Good, and most of them would probably be either Unaligned, Good, or outright Evil. It depends somewhat on base-canon (Manga-Happosai is pretty Chaotic Evil, while Anime-Happosai is... still kind of Chaotic Evil, but capable of selflessness that bumps him a bit closer to Unaligned or just plain Evil), and the cynical side of me says that Good alignments would be the least common of all.
Lawful Good
“An ordered society protects us from evil.”
If you’re Lawful Good, you respect the authority of personal codes of conduct, laws and leaders, and you believe that those codes are the best way of achieving your ideas. Just authority promotes the well-being of its subjects and prevents them from harming one another. Lawful Good characters believe just as strongly as Good ones do in the value of life, and they put even more emphasis on the need for the powerful to protect the weak and downtrodden. The exemplars of the Lawful Good alignment are shining champions of what’s right, honorable, and true, risking, or even sacrificing, their lives to stop the spread of evil in the world.
When leaders exploit their authority for personal gain, when laws grant privileged status to some citizens and reduce others to slavery or untouchable status, law has given in to evil and just authority becomes tyranny. You are not only capable of challenging such injustice, but morally bound to do so. However, you would prefer to work within the system to right such problems rather than resorting to more rebellious and lawless methods.
Good
“Protecting the weak from those who would dominate or kill them is just the right thing to do.”
If you’re a Good character, you believe it is right to aid and protect those in need. You’re not required to sacrifice yourself to help others or to completely ignore your own needs, but you might be asked to place others’ needs above your own… in some cases, even if that means putting yourself in harm’s way. In many ways, that’s the essence of being a heroic adventurer: the people of the town can’t defend themselves from the marauding goblins, so you descend into the dungeon –at significant personal risk- to put an end to the goblin raids.
You can follow rules and respect authority, but you’re keenly aware that power tends to corrupt those who wield it, too often leading them to exploit their power for selfish or evil ends. When that happens, you feel no obligation to follow the law blindly. It’s better for authority to rest in the members of a community rather than the hands of any individual or social class. When law becomes exploitation, it crosses into evil territory, and Good characters feel compelled to fight it.
Good and Evil represent fundamentally different viewpoints, cosmically opposed and unable to coexist in peace. Good and Lawful Good characters, though, get along fine – even if a Good character thinks a Lawful Good companion might be a little too focused on following the law, rather than simply doing the right thing.
Unaligned
“Just let me go about my business.”
If you’re Unaligned, you don’t actively seek to harm others or wish them ill. But you also don’t go out of your way to put yourself at risk without some hope for reward. You support law and order when doing so benefits you. You value your own freedom, without worrying too much about protecting the freedom of others.
A few Unaligned people, and most Unaligned deities, aren’t decided about alignment. Rather, they’ve chosen not to choose, either because they see the benefits of both Good and Evil or because they seem themselves as above the concerns of morality. The Raven Queen and her devotees fall into the latter camp, believing that moral choices are irrelevant to their mission since death comes to all creatures regardless of alignment.
Evil
“It is my right to claim what others possess.”
Evil characters don’t necessarily go out of their way to hurt people, but they’re perfectly willing to take advantage of the weakness of others to acquire what they want.
Evil characters use rules and order to maximize personal gain. They don’t care whether laws hurt other people. They support institutional structures that give them power, even if that power comes at the expense of others’ freedom. Slavery and rigid caste structures are not only acceptable, but desirable to Evil characters, as long as they are in a position to benefit from them.
Chaotic Evil
“I don’t care what I have to do to get what I want.”
Chaotic Evil characters have a complete disregard for others. Each believes that he or she is the only being that matters and kills, steals or betrays others to gain power. Their word is meaningless and their actions destructive. Their worldviews can be so warped that they destroy anything and anyone that doesn’t directly contribute to their interests.
By the standards of Good and Lawful Good people, Chaotic Evil is as abhorrent as Evil, perhaps even more so. Chaotic Evil monsters such as demons and orcs are at least as much of a threat to civilization and general well-being as Evil monsters are. An Evil creature and a Chaotic Evil creature are both opposed to Good, but they don’t have much respect for each other either and rarely cooperate toward common goals.