To go away and sin no more,
But if that effort be too great,
To go away at any rate."
The villain has either been defeated or acknowledges the error of his ways. He surrenders to the hero, expecting to be killed or punished in some other way. Instead, the hero lets him go, telling him to repent for his crimes by doing good deeds. This usually turns the villain into The Atoner and sends him on a Redemption Quest.
May overlap with The Punishment Is the Crime in cases where the hero decides that the villain has been sufficiently punished by his own remorse or other harmful consequences of his deeds. Time may eventually subvert this, and show that the hero really intended Cruel Mercy, or worse, the villain may just go doing more sin. On the other hand, if Rousseau Was Right, then the villain may very well reform themselves and become a force for good in the world.
Compare Let Off by the Detective, when the fate the villain is spared is being processed by the official justice system.
Trope Namer is The Bible, in which Jesus releases an adulteress rather than stone her to death, as was common at the time. Easy, then, to see why the hero who bestows this mercy is often a Messianic Archetype or All-Loving Hero.
- Goku of Dragon Ball Z tries this on Freeza twice. It doesn't work.
- This happens in the Nuts Fujimori manga adaptation of Fire Emblem: Seisen no Keifu. In this adaptation, one of the early bad guys, Kinbois of Verdane, is portayed as deep down not being evil, just someone influencable who was following the wrong path. Sigurd notices this, and lets him live on the promise he will atone for his sins. Kinbois is genuinely moved by this mercy and promises. This turns out to be crucial, as Kinbois' brother Jamuka later fights Sigurd because he believes, in a misunderstanding, that Sigurd has killed his beloved brother in battle: after learning the truth and seeing Sigurd's generosity, Jamuka joins his party.
- Rurouni Kenshin: Several times by Kenshin because of his Thou Shall Not Kill thing. This earns him several friends. He doesn't try it with Shishio Makoto, probably because he recognized that the man is too far gone off the deep end in his belief in Might Makes Right and too dangerous to risk letting him live.
- In Dirty Sympathy Edgeworth decides to let Klavier and Apollo go instead of sending them back to the U.S. to get arrested after verifying that they were being truthful of their justification of their crimes and they truly had no way out of their abuse before everything escalated.
- Through A Diamond Sky: A bit more literal case than most. The villain's Dragon has second thoughts and switches sides to help the heroes and captured Isos. She fully expects Flynn to de-rez her, but Flynn has other ideas, giving her a directive to seek out other Programs and Isos who are in danger of losing their way like she did, and finishing it up by quoting the trope namer.
- In Gandhi a Hindu comes to Gandhi as he's partaking in a fast and says he (the Hindu) is going to Hell, because he killed a Muslim child in revenge for Muslims killing his son. Gandhi tells the man he can repent by finding a Muslim boy whose parents have been killed, and raise him. But here's the kicker: he's to raise the boy as a Muslim.
- The Trope Namer is a story in The Bible, specifically The Four Gospels.
- If you identify "the hero" in the page description with God, you'd have a fairly accurate representation of the Christian doctrines of repentance and salvation.
- Most versions of the story of Momotaro end this way. He beats the oni in battle but, instead of killing them, tells them to change their ways.
- Brother Cadfael discovers the recently-unmasked killer in Monk's Hood on the run... or rather, the killer attacks him, but can't bring himself to murder a monk in cold blood. Cadfael calmly tells him that he 'was never meant to be a murderer', that Cadfael knew his crime was done on impulse when circumstances made it possible, and gives him a sentence of voluntary banishment and always doing good for the rest of his life—oh, and making a confession to a priest as soon as he can and asking him to post it to the sheriff of Shrewsbury (as the man is illiterate) to clear his innocent relation of suspicion.
- Done to the corrupt police chief in The Caves of Steel by Isaac Asimov. Instead of arresting the chief for the murder of a pro-robot, pro-space travel scientist, Elijah and Daneel tell him to rally support for robots and space travel among the Luddite "Medievalists" he worked with. Daneel uses the exact words "Go and sin no more" as Elijah had told him the story of the Trope Namer before.
- Happens to Flambeau, a thief, in the Father Brown mysteries. Specifically, in The Queer Feet, Father Brown catches Flambeau and then lets him go after listening to his confession (and retrieving the loot). Not long afterwards, Flambeau appears as a fellow detective.
- In the Star Trek novel Spock's World, McCoy and Kirk tell the Big Bad to get out of prison and do some good with that intelligence.
- Subverted in Wizard's First Rule. Richard forgives his brother Michael for everything he did to him. However, Richard still has him beheaded as he does not forgive him for crimes he committed against others, feeling he doesn't have the right to. While reasonable, Michael doesn't get to have a trial, either.
- In Doctor Who, the Doctor makes a Sontaran work as a nurse.
- Power Rangers in Space; After Astronema figures out that she's Andros' sister, she turns herself in to the Rangers, and they - minus Andros - have to discuss how to handle this in private. She wonders if they're planning to dump her into a black hole, and Andros doesn't help matters by saying there's one nearby. To her surprise, they pardon her rather quickly.
- In The Sarah Jane Adventures, an alien who had been kidnapping children to use as child soldiers realizes that the war his people were fighting had ended without his knowledge. He allows Sarah Jane Smith to take his life, but she refuses. The alien then promises to return to his homeworld and bring back the humans he had abducted.
- In Batman: Arkham City, you can meet up with Mr. Freeze after you have helped him track down his still-frozen wife Nora. When Freeze says all he wants is for his wife to be healthy again, Batman replies that he should do that and give up his life of crime, because he's better than it.
- This is a plot-point in BioShock Infinite. Booker's sinful past of war-crimes and heinous acts against Native Americans led to him deciding to accept a baptism in order to wash away his sins and become a new, virtuous man. However, he misinterpreted the "Go Forth and Sin No More" line to mean "you are now unable to sin no matter what you do" instead of "stop sinning you asshole". This led him to commit even worse acts, believing they were virtuous acts just because he was the one doing them.
- You can potentially do this in Dishonored with Daud, the final assassination target. After beating his target in a duel, Corvo listens to his target lament their fate, and ends it with a call to finish them. Corvo can, if the player chooses, simply holster his weapon and walk away, which stuns both the target and the Outsider.
- A possible judgement for a Grey Warden in Dragon Age: Inquisition. Ser Ruth Hands herself over to the Inquisition in order to atone for the crimes she feels the order has committed. You can say Off with Her Head! or send her in the deep roads, or invoke this trope. She's baffled as she leaves the throne room, but a later report shows it actually worked out well.
- Grand Theft Auto IV has a few missions end with an option to finish a cornered enemy off with a Coup de Grâce or get rid of them with this trope.
- After beating her in Knights of the Old Republic II, the player has several options for what to do with the fallen Atris. One of the light-side choices is to show her mercy in this fashion by acknowledging how the Exile's choice to fight in the Mandalorian Wars contributed to her fall.
- In the The Legend Of Zelda CDI Games, after Duke Onkled betrayed the King of Hyrule by siding with Ganon, he gets off by being told to "Scrub all the floors in Hyrule."
- In MARDEK, Gope gets this treatment from Mardek and Duegan. Unless you decide otherwise. He shows up later on and gives you an item needed to get to a bonus area, and again in the next game as a traveling merchant who can be useful for getting supplies in exotic places.
- In several Mass Effect games, you can either kill an enemy as a Renegade decision or let them go for Paragon points. Most, but definitely not all, of the time it will work out in Shepard's favor to spare the character.
- In Star Wars: The Old Republic, in the Jedi Knight quest line, you have an option to let one of the top Imperial agent go despite all the trouble he caused you. If you do, he will send a letter saying that he had assumed a new identity and found a new life in the Republic.