No more Detect Good. Detect Holy instead.

[PairO'Dice Lost]

I don't see what points your talking about "raised upthread".

Sorry, got this thread confused with the other alignment one going on at the moment. Basically, the point of alignment is not, and has never been, simply to put big labels on creatures saying "these are bad, you can kill them" and "these are good, you can't kill them." Alignments serve as roleplaying prompts and mechanical hooks, as I mentioned, at multiple levels of granularity.

Using alignment as a roleplaying prompt has three main benefits:

1) Information density. One of the major benefits of D&D's race and class system compared to more freeform systems is the ability to briefly convey a lot of information about your character. You can give a newbie one list of races and one list of classes, have them pick something from each, and go from there, and an experienced player saying "I'm an Elf Ranger" conveys a heck of a lot of information about their character, compared to more fiddly games like GURPS where a newb has to do everything from scratch and a veteran can't convey detail "packages" in the same way. Alignment is basically that for roleplaying prompts: Saying "here are six flavors of general moral and ethical outlook, pick one" can get a newbie thinking about character motivations and such without going through long lists of character traits or whatever, and "I'm a CE Elf Ranger" vs. "I'm a LG Elf Ranger" is a quick way to convey party dynamics and such between veterans.

2) Universality. In games with defined settings, a character's moral and ethical outlook usually has something to do with the religions or organizations they belong to; in a real-world setting a character might be a Catholic or a Buddhist, and in Star Wars they might be a Jedi or a Sith, and each of those four things gives you a good sketch of their outlooks on life. But there are a lot of religions and organizations even in a single setting--if I tell you my d20 Modern character is a Zoroastrian or that my Star Wars character is a White Current Adept, do you know offhand what that means about their philosophy?--and D&D has a bunch of different settings to the point that "I worship the sun god" means very different things depending on whether you're talking about Pelor in Greyhawk, Amaunator in FR, Dol Arrah in Eberron, or Paraelemental Sun in Dark Sun.

Alignments, meanwhile, are constant across settings (to the point that people can meaningfully talk about what alignment characters from non-D&D settings would be) and there are exactly nine of them you need to remember.

3) Overlaying. People in this thread have talked about replacing alignments with character traits or the like, but the great thing is that they're not mutually exclusive, you can use both (as 5e kinda sorta does). What's more, adding that extra layer can give you more depth: a character who's Altruistic is one thing, but a character who is Lawful Evil and Altruistic? Figuring out how to express that gives you a great prompt right there. Conversely, alignment can be ignored in cases where you think it doesn't make sense (see the bit about swords-and-sorcery in my last post) because D&D functions just fine if you arbitrarily declare that all creatures are TN and alignment magic is gone.

As for mechanical hooks, people have already given examples of systems that work based on alignment systems--Dark Side points, join-Cthulhu-if-you-go-insane sanity meters, and so forth--and then you have the usual detecting/smiting/etc. stuff as well. If you want to represent profane shrines, corrupted swamps, and so forth, there's really no substitute for a mechanical alignment system, especially in a D&D-like setting where "evil" means everything from demons to undead to aboleths so you can't just point to a handful of creatures or one kind of magic or whatever and key everything to those.

Edit: also you haven't actually answered my question. So I'll state it again: why do you need the confirmation, even when its so obvious beyond all reasonable doubt that they are evil?

Again, even if detect evil were (anti)magically removed from the game, there are still plenty of benefits to having alignment around, Evil is not just a neon sign in the shape of a skull.

That's good/evil, mind you. I've yet to see a plausible case of the law/chaos helping with anything. Really, it seems that the entire D&D alignment system is essentially a tool for being able to slap a big, red "EVIL" label on some people or things. Everything else is just twisting logic into knots trying to pretend it's some kind of sensible larger framework.

Law and Chaos have a much vaster pedigree than Good and Evil in terms of fiction and mythology alike. Lots of real-world religions have a fundamental law-vs.-chaos struggle in their mythology (can't give specific examples here, obviously) and while Moorcock's specific take on it was the closest inspiration for D&D there's plenty of other authors and series who delve into that conflict. If anything, the ethical axis is more important and influential than the moral one both at a personal scale ("Sure, you want to be the good guy, but what kind of good guy?") and a cosmic one, and if you put a gun to my head and forced me to ditch one of the two axes in my games I'd ditch Good and Evil and keep Law and Chaos.

In what way would my player experience suffer if I say in session 0 "You are all fighting on the side of truth, justice, and cosmogical goodness" rather than implementing a 3x3 grid system and telling them to only be in these three arbitrary squares?

Those "three arbitrary squares" are broad enough to contain literally the entire span of real-world moral and ethical philosophy and a broad variety of characters from fiction, mythology, and history can fit in each of those squares.

In what way *specifically* would my players be unable to experience a cosmological struggle by my decision not to label things as NE or LG? (Assuming I'm playing in 5e, where alignment has no associated mechanics.)

If you were to describe the Blood War to your players, how would you do that? Would you, perchance, go into detail about how demons are power-hungry maniacs who give into every evil whim and want to carve up the multiverse into little fiefdoms for every demon prince while devils are cunning and strategic types who embody the evils of bureacracy and believe the multiverse must be placed under the Baatorian yoke and so on and so forth?

Congratulations, you've just reinvented the LE and CE labels, you've just gone out of your way not to use labels because they're bad or something.

Like, seriously, Order and Chaos show up all over basically every mythological system (see e.g. here and here for some examples), and Good and Evil has been doing the same thing since at least Zoroastrianism. I simply don't understand why applying near-universal symbolic mythical principles to a roleplaying game involving creatures, places, items, and plots from those same myths is such a controversial idea.

In what way *specifically* am I depriving them by not using a "corruption points" system and instead working through the effects of a character falling to evil organically, working together with the player?

Serious answer? Many character arcs that involve explicitly pre-planning things between the player and the GM are generally either very fragile or very capricious.

Fragile, because unless you heavily railroad the party and you have a very cooperative group, the plot can go in totally unforeseen directions that require making drastic alterations to the plot arc or perhaps render the planned arc impossible, other players can do things that derail the arc either intentionally (e.g. they don't want to deal with a fall-and-redemption arc in the game so they sabotage it) or accidentally (e.g. a cleric PC saves an important NPC in the PC-to-fall's backstory who would otherwise have set them on their dark path), the player of the PC-to-fall can derail it themselves either accidentally (e.g. they realize that, whoops, after something that happened a few sessions ago they need to add in some epicycles so their arc still make sense) or intentionally (e.g. they come up with an awesome idea mid-campaign and want to take things in a different direction), and so on.

Capricious, because if there are no hard-and-fast rules for corruption then a GM has to issue rulings on a bunch of game elements, the GM and players might disagree how corrupting certain acts are (see: every player ever who wanted to play a Mace Windu-style "carefully walk the boundary between Light and Dark" Gray Jedi character in a Star Wars game run by a "one Dark Side act and you fall" GM), and so on.

And then there's the basic fact that a lot of games have uncertain schedules or varying group compositions or rotating GMs or are plot-less sandboxes or whatever, and pre-planning character arcs just doesn't make sense for logistical reasons either in- or out-of-game.

Having defined corruption mechanics puts everyone on the same page, ensures fairness and impartiality, removes the need to pre-plan character arcs while not preventing someone from planning them, and such. Plus, it allows for more organic "falling" scenarios, where there's a mechanic right in the book that says you can do X at the cost of Y and you hadn't planned for your character to take that step but y'know this boss is pretty hard and you could use a bit more oomph in your spells/Force powers/etc., so why not just dip a toe in the deep end of the morality pool...., adding spontaneity and character variety in the same way that wizards learning spells from scrolls instead of picking them at level-up, getting random treasure and incorporating that into your build, and the like can.

ON CORRUPTION SYSTEMS:
This presents a bit of a problem. You said Alignment is Descriptive, but Corruption Systems are Prescriptive. And also you said using Alignment Prescriptively is being a bad GM, but Alignment Systems are always good for High Fantasy, but a High Fantasy system using Prescriptive Alignment is... good for High Fantasy?

You're using very...interesting definitions of descriptive and prescriptive, here. When I used them, and pretty much every other time I've seen them used in alignment discussions, here's what it means: some people think alignment is prescriptive, where you put CG on your PC's character sheet and now you're a robot locked into some random CG personality until the end of time and if they act outside their alignment the DM says "You can't do that, you're CG!", while in fact it is descriptive, where you put CG on your PC's character sheet but can act however you feel your character would and if they act outside their alignment then their alignment changes to match.

Similarly, Dark Side points are descriptive, in that if you do Dark Side-y things you get Dark Side points and if you keep doing Dark Side-y things you keep getting Dark Side points until you fall off the moral cliff but if you try to atone you lose Dark Side points until you come back from the brink. A prescriptive corruption system would be a setup where, I dunno, as soon as you have a single Dark Side point you're not allowed to be polite to people and are obligated to kick one puppy per week, or something.

On Dungeon World:
I mean, according to you so long as it has a Detect Evil spell it has alignment, and Alignment is required for High Fantasy, so DW should be able to do High Fantasy just fine, since all that's needed (according to you) is Alignment and Combat systems. Yet it's an affront to High Fantasy and made for Sword and Sorcery....

"High fantasy games really need an alignment system" does not at all imply "any game with an alignment system is automatically a high fantasy system," any more than "school buses need to have a flashing stop sign on them to comply with local laws" implies "putting flashing red lights on your car legally turns it into a school bus."

I pointed out the Paladin's Detect Evil ability not because it's some secret sauce that the alignment system requires to function, but because everyone who's against alignment has been focusing all their ire on detect evil as the primary sin of the alignment system for reasons I can't fathom, and then you turned around and held up Dungeon World, a game with an alignment system and Detect Evil, as a counterexample to D&D, that's all.

If you're going to bring the EU into things, it needs to be the whole EU, and when you do that the notion of the Force as binary really falls aparnt.

Hardly. The Potentium may claim that the Force is innately good and the Aing-Tii may believe that there are more shades of nuance between pure Light and pure Dark, but that doesn't mean that their views are accurate (the Potentium's "Oh, there's no such thing as the Dark Side, as long as you don't mean to kill someone with Force Lightning it's hunky dory!" stance is pretty Sith-y in outlook) or that their views contradict those of all the other Force traditions (the Aing-Tii may think the Force has "rainbow shades" but that's basically the same as saying that there are gradations of Light and Dark, and no powers they use fall outside the standard dichotomy).

I have no problem with "Archeronian" as an alignment. By problem is specifically with the Good/Evil and Law/Chaos axes D&D uses, because I don't think they're useful or meaningful.

Why exactly is "Acheronian" perfectly acceptable but "Lawful Evil with Lawful tendencies" an abomination that must be deleted from the game? The point of the Great Wheel is that adjacent planes and different layers within the same plane have very similar but importantly different philosophical outlooks, and if you're going to use a bunch of planar alignments arranged by similarity but then refuse to acknowledge said similarity--and refuse to use labels that are applicable in settings with different cosmologies--then that just seems like being contrary for the sake of contrariness.

Why? That's the plot of The Stormlight Archive, which doesn't have an alignment system, at least not in the way D&D does.

The entire Knights Radiant setup involves holy knights who gain magical powers from oaths forged with higher beings, complete with falling and losing their powers if they break said oaths, and as Kabsal said, "Everything has its opposite, Shallan. The Almighty is a force of good. To balance his goodness, the Cosmere needed the Voidbringers as his opposite," where the Voidbringers are blatant "demon-corrupted mortal" types complete with glowing red eyes and red stormlight to set them apart from the good guys who have glowing light eyes and blue stormlight.

Paladin Kaladin may not have a sheet in the back of the book that says "Lawful Good Human Fighter 5/Windrunner 3" on it, but that's still a textbook example of when an alignment system would fit perfectly with an RPG implementation of the setting.