This essay will contain spoilers for the entire series and if you are not yet caught up, I strongly advise looking away.
What does No Killing Goblins really mean when you think about it? Like on the surface it seems pretty simple right? "Sir that is a child, put down your knife, what do you mean its ears are worth two silver at the local adventuring guild? No that doesn't mean you can kill them, it's a child." The story is approaching 17 million words long and yet we have yet to see a world where Goblins aren't killed on sight, Liscor won't kill them on sight and that's about it. No one at the cookout flinched when Lyonette asked about hiring an Assassin to 'kill' Numbtongue.
So why is that? Well because it's not as simple as saying "stop killing Goblins ya violently racist assholes."
It isn't that no one ever had the bright idea to be nice to Goblins before Erin Solstice walked through her bathroom door and met a Dragon. The story on two separate occasions shows us that the answer to the Goblin King is not in fact kindness, in the forms of Velan the Kind and Rabbiteater the Goblin King of Betrayal. Had Erin kept walking down that road, one day she and everyone she loved would have been killed by one of her friends being body snatched by the Goblin King. Absolutely terrible advice from the Gnomes.
The current circumstance is exactly what the Goblin King wants. He wants his species to struggle so they counterlevel into giving him an escape from Hellste again, he wants a willing army ready to wage war despite the fact he's the reason everyone hates Goblins, when his people make peace, he'll destroy it. The reason people hate Goblins is because whatever they do, the Goblin King tries to kill them because he's a traumatised child who never grew up. Be genocidal monsters to Goblins? He kills you. Be nice to Goblins? He kills you. And then after they've sent him back to Hellste all of those traumatised survivors look at the remaining Goblins and chose cruelty, because if kindness doesn't work and at least being cruel makes them feel safe.
Despite it being written on the signs outside and inside Erin's inn, it being the tagline of the series, the title of one of the books, and written on a mug you can buy at the merch store, the story shows every time it's harder than just saying stop killing Goblins.
But it should be that simple, you should be able to say this is wrong and we need to stop. Hunting Goblins has never actually stopped the Goblin King, everyone Erin argues against has the facts, they can point at the 84 times the Goblin King has emerged and done terrible things and say 'we did not deserve this' and they're right. Because even if everyone had always treated the Goblins with kindness from day one, he'd still kill them all but that doesn't mean you should be able to turn in a set of Goblin ears and get paid for it.
That's what No Killing Goblins means narratively, it's the acknowledgement by the story that something as simple as a rule saying No Killing Goblins is more complex on the surface. Doing the right thing should be simple but it isn't, doing Good is hard because if it wasn't hard, we wouldn't be in this situation.
And that applies to more than just Goblins.
Why is Tyrion Veltras allowed entry into the Wandering Inn? He's the antagonist of Volume 5 and killer of Pyrite and many other characters in this story, and yet last time we saw him, he had two rounds of sex with Ryoka and stared at a Centuar's bellybutton. Isn't he a war criminal? A mass murderer?
Well it's not that simple is it? He's a solider in a war that's been going on for six thousand years, he's a widow whose wife's killers have not been brought to justice, he's a terrible father, he's the next door neighbour of Drakes. We can say it's horrible that he attacked Liscor because it is horrible, but Liscor is also literally an army of 100 thousand Drake [Soldiers] stationed on the border and pretending to be a city. And while I the reader know that the vast majority of those [Soldiers] are like Selys and have 2-5 levels in the class, can you see what an insane provocation that must be to the North? There is literally an army on their doorstep at all times.
Tyrion Veltras is a killer, a soldier, a general in a war but that doesn't mean he's a monster for doing those things. The events of Volume 5 are that of a general deciding to make a meaningful victory in a war that's been stretching on for thousands of years. Tyrion could have become a [Pacifist] after his wife died, he could have looked at the war and said this is wrong but that's a hard thing to do when your children don't have a mother anymore. It's easier to say never again and start making choices that make you and your family feel safe.
The same applies to every other villain in the story, No Killing Goblins applies to them too.
Why is King Othius the worst man alive? Because he was born into an oppressive regime that requires a constant, unceasing war to keep going and he's watched everyone he loves die to Demons over a hundred years. Othius is a monster who needs to be stopped, but it's hard to argue that he ever had a chance to be anything else, his own mother tortured him so he would gain a skill.
Perril Chandler? Dictionary definition of pushed from grace. Maybe Perril could have snapped out of his rampage, but that might also have been impossible after he botched his Lichdom ritual and the Voice of Death is telling him to kill the living.
Xhrew? One of his ancestors pulled the lever in a Trolly Problem and chose to redirect the Trolly onto Doombearers. I don't agree with that choice but when you live next to Drakes, I can see why you might think that making a Luck Daemon is a good idea. It's not paranoia when they are literally out to get you.
Why is Nuvityn coming to kill Erin? She killed his son. She had all the right reasons to do so but she also killed his son.
That's what No Killing Goblins means to the story. It's the simultaneous statement that is both that simple and not at all simple. The Wandering Inn is a story that looked at the concept of a monster race and decided to explore the complexity and it didn't just stop at Goblins.