I've generally been of the opinion that Alignment is a fairly useless limb in OSR-style, dungeon crawl-which-challenges-the-player-rather-than-the-character, find the treasure and get out challenge-based adventuring.
Out of curiosity, I started thinking what aligment could be used for in that situation, and I came up with this simple idea. (I've been going on a kick of trying to redesign old-school D&D in a way which makes sense to me while trying to keep as much of it intact as possible, somewhat inspired by Eero's Primitive D&D discussions.)
Cosmic or Metaphysical Alignment
This represents a character's alignment with cosmic forces.
Most people and creatures are unaligned, or neutral: you do not claim any stake in the great Eternal Conflict of Law and Chaos. (Presumably some ancient and cosmic battle of forces which is important to the backstory of your campaign, if you're into that kind of thing.)
However, some people and some creatures intentionally declare themselves (or perhaps undergo some kind of ritual) to attach themselves, to henceforth belong to one faction or another.
Law: aligned with deities of light and order, obey tradition, follow cosmic tradition, seek to rebuild the old ways.
Chaos: aligned with deities of chaos and growth/change, disobey tradition, seek to bring down the old and move into the new, look ahead to the future.
This is relevant if:
a) You have active deities in your campaign.
b) You have spells, items, and effects which require alignment to function (something like "Protection from Evil" would, instead, be "Protection from Chaos", and help defend against anything specifically aligned with the forces of Chaos and associated deities).
Otherwise, it seems pretty safe to scrap it altogether. The next bit is more relevant:
We all know adventurers are out to collect treasure and get rich. Not the highest moral pursuits in the world.
I believe strongly in the value of a D&D which is premised on XP representing successful adventuring: you effectively "score points" for being clever and lucky enough to collect treasure under challenging circumstances. This applies to all characters, or the game no longer functions as written.
Still, there is variation in adventurer outlook on the world, and it affects their view of life and their goals as adventurers. This is represented by how these characters' players score XP in the game.
Good characters get XP for treasure recovered (i.e. it is now rightfully yours), and for lives saved (10 XP per commoner saved, 20 XP per noble-born, 50 XP per royal).
(Alternately, they score half the XP for treasure recovered, and then the full amount again if and when the treasure is returned to its rightful owner.)
Neutral characters get XP for treasure recovered under challenging circumstances, and then half again when they spend or invest it. (As some OSR circles handle experience.)
Evil characters get XP for treasure... of any kind. You can steal, extort, kill or murder, for instance; so long as you end up with the treasure, you get the XP for it.
This gives different alignments roles to play which are aligned with the way XP functions in the game (whether it is balanced remains to be seen, of course - perhaps the numbers or ratios may need to be adjusted). If alignment is supposed to create intra-party conflict and lead characters to advocate for certain actions ("No, let's just kill the hostages and take their stuff for ourselves!"), then this should accomplish that function nicely.
Any thoughts? Would you use this in a D&D game?
Have you ever used something like this?