A little alignment "grid" I started working on a while ago is a bit broader and uses smaller numbers for each axis, and allows a character to be evil or good in one way while being the opposite in some other way, i.e. an egocentric but honorable paladin who still counts as being lawful good, while allowing decent variance amongst neutral characters too. I made several small axes to measure alignments, and the total point value of different components determines the character's "by the book" alignment for purposes of Detect and Protection From spells etc. The higher the score on any given axis, the more Good or Lawful the character is considered to be (depending on whether it's a good/evil axis or law/chaos axis).
A Good/Evil score of 11, 12, or 13 is morally Neutral; a Law/Chaos score of 11, 12, or 13 is ethically Neutral. Good/Evil scores of 14+ are morally Good, while Good/Evil scores of 10- are morally Evil. Law/Chaos scores of 14+ are ethically Lawful, while Law/Chaos scores of 10- are ethically Chaotic. For greater variance, you might use a range of 10-14 for Neutrality, making the Good/Lawful range 15-20 and the Evil/Chaotic range 1-9. Paladins probably would not be allowed any real low scores for Righteousness or Compassion, considering what's specified in the PH's paladin oath, and likewise with Veracity and Lawfulness.
