Do not remove alignment from DnD. It’s not what you think it is. It doesn’t say that all orcs are evil, it’s not a straightjacket for your players’ actions, and it’s not some impossibly vague or nebulous moral system that lets paladins massacre drow children because they’re evil.

Firstly, alignment is a description of a fundament of ‘standard’ DnD settings: good and evil are objective realities. In that fantasy world, they represent facets of nature as real to the characters as physics and chemistry are to us. This means that there are acts that are inarguably good or evil. If you murder someone, that is evil. If you torture, oppress, or enslave people, that is evil. Even if your motivation is for good, evil acts are still evil. Conversely, if you act altruistically, redeem evil individuals, save those in need, provide for the less fortunate, or otherwise put the needs of others before your own, that is good. For more examples and common objections, I’d point you towards two handbooks from the 3.x era: the Book of Exalted Deeds and the Book of Vile Darkness. Do be advised though... The BoVD was written to be edgy, so a lot of the items and spells are intentionally provocative. Both BoED and BoVD cover the nature of good and evil in the first chapter of each book, so you can get what you need without delving into sweaty degeneracy. 

There’s some wiggle room for discussion or debate about morality in DnD worlds, primarily around concepts of whether one’s motivation or the outcome is more important, but in the 20 years I’ve been tossing dice, I can count the number of times the players and DM couldn’t come to an agreement on one hand.

Alright, we’re good? If you can accept that a core assumption about DnD worlds is an objective morality, we’ll move on. If you can’t or won’t accept that aspect of the game, feel free to throw alignment out; you’re on your own though when your players justify torturing an NPC for vital information or robbing the village’s peasants for all their money is fine because the heroes serve the greater good.

For the rest of us, let’s plow ahead and hit the point that I think trips most people up: how does alignment work with intelligent creatures and free will? Player characters obviously have free will, but what about all the monsters and NPC races? If drow or orcs or goblins are evil inherently, isn’t that reductive and somehow translate to racism in the real world? Crack open any monster book from 3.x or earlier and you’ll find this bit in the section describing how to read the monsters’ stat blocks:

So, when DnD tells you that Drow are Usually Neutral Evil and Orcs are Usually Chaotic Evil, it is not saying that ALL of them are irredeemably evil! They are just very likely to be evil, as they’ve come from cultures steeped in evil or are influenced by an evil god or are touched by a fiendish plane of evil. There’s still room for exceptions, but it will be better than a coin toss’s odds that the creature is evil. This doesn’t negate free will or prevent you from writing stories about outcasts trying to reform their peoples’ evil ways. It simply means that those uncommon examples aren’t the norm.

The only creatures that you will find that are Always an alignment are base, elemental creatures that are deeply entwined with the magical nature of the planes or divine forces. Demons, Devils, Celestials, Dragons, Elementals, Slaad, Undead, Modrons, and the like are always (still room for renegades, though much more rare!) are too intrinsically influenced by the alignments to vary. There is an interesting conversation to be had about whether or not these Always creatures have free will or not. 

Note: I’m not sure if 4e or 5e monster manuals have this same setup and am too lazy to check, but I’ll bet it’s in there somewhere.

Lastly, and perhaps the easiest point, a player character’s alignment isn’t a straightjacket that limits their options. Alignment is descriptive rather than proscriptive: a character is good or evil because they do good or evil rather than doing good or evil because they are good or evil. A good character can have a moment of weakness and do something evil just as readily as an evil character might have a pang of conscience and do good. If a character consistently starts to behave in a way contrary to their alignment, then it might be time to consider if character’s alignment has shifted to something new. Has their outlook changed? Is a deeply held belief shaken? Some new information giving them a new perspective? In the business, we call that roleplaying gold. Generally, this is something that takes place over a longer period of time, but if the character encounters something that absolutely shatters their perception of the world, don’t be afraid to let that impact shift a character’s alignment.

If I’ve done my grognard’s duty with anything approaching competence, you now understand alignment better and can make an informed decision about whether or not to keep it in your home games rather than kept swept up in reductive arguments from twitter people that don’t play the game in the first place. If folks are interested, I’ll do a bit about ways you can really make alignment shine in your games.

Also, in case it wasn’t common knowledge, law and chaos follow the same principles... But instead of being two diametrically opposed forces as good and evil, law is simply better than chaos. Chaos is dumb.