By all means, keep it as a module. It can easily be taken out or put in. At the core, it should be fluff. The great thing about fluff is it can be ignored or rewritten without consequence. If there's one thing the game (regardless of edition) has taught me over the years, it's that fluff can be altered and played with easily. But, apparently we can't have nice things because whining is the better solution.
Disgruntled ghost of the Knights of W.T.F. (Keep D&D alive, end the edition wars!)
"And if you gaze for long into an abyss, the abyss gazes also into you." - Friedrich Nietzsche
Disclaimer: Most of my posts are based on opinions (and are sometimes humorous, other times inspirational)
The only ways alignments can please (almost) everyone: - There are no mechanics tied to them - They are optional - The game is not altered one whit if a group decides to ignore them altogether or use them extensively
I have a problem with alignment that nobody else has mentioned, which is that I think it is a very bad thing for young and new roleplayers. I have seen many gamers who have basically been taught by the books that roleplaying means adopting a bizarre stance on the world and ramming it down the game's throat until it explodes. Obviously, mature, intelligent gamers can use alignment in a way that isn't stupid. But give alignment to a new gamer, or a younger gamer, and it can skew their idea of what it is to roleplay a character. Alignment is an easy cop-out, and teaches players the wrong ideas.
I also have even met gamers who have somehow convinced themselves alignment is actually somehow applicable to the real world, describing themselves in alignment terms, analyzing film and literature with the clumsy beating stick of alignment, and even judging the actions of other people in alignment terms. I think this is bad for reasons outside of gameplay concerns. Alignment is one of those things that teaches all the wrong lessons to immature, younger people. I would personally prefer to see it die in a fire.
"So shall it be! Dear-bought those songs shall be be accounted, and yet shall be well-bought. For the price could be no other. Thus even as Eru spoke to us shall beauty not before conceived be brought into Eä, and evil yet be good to have been."
For some people, alignment will suck. For others, it helps.
Because it's subjective, it can only be approached subjectively. Thus, it should be an option. Given it's place in the game, put the option in the DMG or PHB.
Personally, I'd like to just have Paladin represent someone rewarded with power for adhering to a code. This code can be plugged in as the DM chooses. They've already done this in the 3.X UA, though I admit it might not be balanced at all.
My biggest beef with alignment is even in places where it's kind of a tool for various things, it's not a very good one. As an indicator of how a creature is generally supposed to act? On occasion it's vaguely useful for that... but not that useful. It's pretty (extremely) rare that a creature's alignment is worth much at all in terms of dealing with how it responds to things on its own, and once you have an actual useful description of how the creature acts, then having the alignment doesn't add much. Even if you reduce it to just fluff - which is a good start - fluff still has a responsiblity to be good and useful as fluff, which D&D's grid alignment is not - and where it is at least conceivably useful, it's still worse than alternate systems.
I actually don't mind some kind of ethos/mechanics interaction - I think that the primary reason that alignment/mechanics interactions suck is that the D&D alignment system sucks, not that interplay between a characters' ethos and the mechanics suck. (A lot of alignment/mechanics interactions also suck because they're not even consistant with the stupid alignment system anyway - druid alignment restrictions in 3.5 are a good example. Those are a lousy design on top of being built on top of a lousy ethos-tracking system.)
The things that are bad about the D&D alignment system, at a very zoomed-out level, are that the terms involved are overloaded, that they don't put characters that are in alignment into the same boxes, and they put characters that would not react to a single situation in the same fashion or feel the same way about basically anything into the same boxes. When you start hanging alignment restrictions on them, you end up with situations where a character with an extremely unmonklike way of approaching the world can be a monk, and a character with an extremely monklike way of approaching the world cannot, because "lawfulness", in all the myriad vaguely-overlapping-but-not-really ways that it's semi-defined, is an extraordinarily poor way of capturing the notion that someone should probably be disciplined and orderly to be a monk. (Assuming you think that's necessary, which it obviously isn't.)
What I'd like to see - if there's going to be any kind of ethos system - is just chucking out the grid entirely, and give characters a place to list what their actual ethos are. For example, instead of "chaotic", a character's values/allegiences might include "liberation", "living as I wish", "fall of civilization", "taking risks", "sticking it to the man", "demons", "hated enemy (Lawful Outsiders)," "wrenching the sanity from every soul by unleashing eldritch horrors across the planes," or "Olidammara".
Jozan the Cleric, rather than being having "NG" written on his sheet, has "Pelor & His Church", "Hated Enemy (Undead)", "The Common Good", "Protecting My Friends", "See Exciting New Things", "Personal Purity", "Love Interest (Ember the Monk)", "Selflessness" and "Rivalry (Hennet the Sorcerer)" as his "alignment". (I have no idea if those are things Jozan actually cares about; I just made them up. Pretend I picked more appropriate things if you know more about Jozan the Cleric.)
He's acting in accordance with his alignment when he acts in line with those things, and he's acting against his alignment when he undermines or ignores those things. He might gain or lose values and allegiences over time. Things currently handled by alignment could be handled by looking at the list. For example, rather than having "lawful" as a requirement for being a monk, they could have "Disciplined" as a requirement, and if they ever lose that alignment facet, then they lose the ability to advance as a monk. (Or some other ethos facet as a requirement. Doesn't have to be "disciplined".)
I know that's all super un-D&D, so maybe it's more module-y, but I think it's nice.
Dwarves invented beer so they could toast to their axes. Dwarves invented axes to kill people and take their beer.
Swanmay Syndrome: Despite the percentages given in the Monster Manual, in reality 100% of groups of swans contain a Swanmay, because otherwise the DM would not have put any swans in the game.
My biggest beef with alignment is even in places where it's kind of a tool for various things, it's not a very good one. As an indicator of how a creature is generally supposed to act? On occasion it's vaguely useful for that... but not that useful. It's pretty (extremely) rare that a creature's alignment is worth much at all in terms of dealing with how it responds to things on its own, and once you have an actual useful description of how the creature acts, then having the alignment doesn't add much. Even if you reduce it to just fluff - which is a good start - fluff still has a responsiblity to be good and useful as fluff, which D&D's grid alignment is not - and where it is at least conceivably useful, it's still worse than alternate systems.
I actually don't mind some kind of ethos/mechanics interaction - I think that the primary reason that alignment/mechanics interactions suck is that the D&D alignment system sucks, not that interplay between a characters' ethos and the mechanics suck. (A lot of alignment/mechanics interactions also suck because they're not even consistant with the stupid alignment system anyway - druid alignment restrictions in 3.5 are a good example. Those are a lousy design on top of being built on top of a lousy ethos-tracking system.)
The things that are bad about the D&D alignment system, at a very zoomed-out level, are that the terms involved are overloaded, that they don't put characters that are in alignment into the same boxes, and they put characters that would not react to a single situation in the same fashion or feel the same way about basically anything into the same boxes. When you start hanging alignment restrictions on them, you end up with situations where a character with an extremely unmonklike way of approaching the world can be a monk, and a character with an extremely monklike way of approaching the world cannot, because "lawfulness", in all the myriad vaguely-overlapping-but-not-really ways that it's semi-defined, is an extraordinarily poor way of capturing the notion that someone should probably be disciplined and orderly to be a monk. (Assuming you think that's necessary, which it obviously isn't.)
What I'd like to see - if there's going to be any kind of ethos system - is just chucking out the grid entirely, and give characters a place to list what their actual ethos are. For example, instead of "chaotic", a character's values/allegiences might include "liberation", "living as I wish", "fall of civilization", "taking risks", "sticking it to the man", "demons", "hated enemy (Lawful Outsiders)," "wrenching the sanity from every soul by unleashing eldritch horrors across the planes," or "Olidammara".
Jozan the Cleric, rather than being having "NG" written on his sheet, has "Pelor & His Church", "Hated Enemy (Undead)", "The Common Good", "Protecting My Friends", "See Exciting New Things", "Personal Purity", "Love Interest (Ember the Monk)", "Selflessness" and "Rivalry (Hennet the Sorcerer)" as his "alignment". (I have no idea if those are things Jozan actually cares about; I just made them up. Pretend I picked more appropriate things if you know more about Jozan the Cleric.)
He's acting in accordance with his alignment when he acts in line with those things, and he's acting against his alignment when he undermines or ignores those things. He might gain or lose values and allegiences over time. Things currently handled by alignment could be handled by looking at the list. For example, rather than having "lawful" as a requirement for being a monk, they could have "Disciplined" as a requirement, and if they ever lose that alignment facet, then they lose the ability to advance as a monk. (Or some other ethos facet as a requirement. Doesn't have to be "disciplined".)
I know that's all super un-D&D, so maybe it's more module-y, but I think it's nice.
In short, you'd likely prefer the D20 Modern approach with allegience?
Say where you could say you ally with "Waterdeep", "Merchants", "Rule by capital" and your values are "indifference", "greed", etc... This would indicate that your character is stingy, not nice, and focuses on cash around the city. Now, this could potentially be even better for RP! And allegience is one of my favorite things about D20 Modern that I wish stuck around. (Heck, I'd prefer that to 4th's torn apart take on alignment. They may as well have ditched it... or at least kill lawful good and chaotic evil.)
Perhaps alignment works for factions in Planescape, but more so as the planes themselves are viewed by the many scholars. Perhaps it's best left to fluff and module for the table to decide.
Disgruntled ghost of the Knights of W.T.F. (Keep D&D alive, end the edition wars!)
"And if you gaze for long into an abyss, the abyss gazes also into you." - Friedrich Nietzsche
Disclaimer: Most of my posts are based on opinions (and are sometimes humorous, other times inspirational)
"Perhaps alignment works for factions in Planescape, but more so as the planes themselves are viewed by the many scholars. Perhaps it's best left to fluff and module for the table to decide"
For me alignment worked in Planescape by testing the idea, kinda like there are rules [of myths and religion] the protags in Vertigo comics pushed up against.
I think it works well if people agree on what alignment is or accept that there are different interpretations. It provides a metaphyiscal set of axes that make D&D a "moral world", to use one author's reasoning on the appeal of fantasy.
Magic is just Scifi psionics without metaphyiscal morality underpinning the setting. This is why I like the moral+ethical axes. That said, there are different ways to do this and the best thing to do is to make its influence on mechanics modular.