When I play with fire,
I don't want to get myself burned.
To thine own self be true,
Tropes about characters shifting on the morality axis, redemption and corruption.
See Sorting Algorithm of Face Heel Turning
for a sheet of factors figuring into the probability of a turn.
This is a sub-index of Betrayal Tropes
. Spoilers abound.
Good to Evil
Neutral to Aligned
- Adaptational Villainy
An adaptation of a work makes a character more villainous than they were in the source material.
- Bait the Dog
A character set up to be the more 'charming' type of evil is revealed to be much nastier than their initial impression.
- Became Their Own Antithesis
The character has changed so much that an alignment shift is the logical conclusion of his Character Development.
- Being Tortured Makes You Evil
A character who undergoes prolonged torture gives up on their ideals and morality and joins Team Evil.
- Beware the Nice Ones (sometimes)
A gentle, sweet, or polite character shows a nasty side.
- Break the Cutie (sometimes)
Destroying The Pollyanna's optimism just might turn her evil.
- Came Back Wrong (sometimes)
An alignment change can be one of the ways in which the resurrected character is now "wrong."
- Can't Take Criticism (sometimes)
A character who resents those who point out his flaws may double down and become even worse.
- Character Derailment
Either, technically, but good to evil is more common because it's more of a surprise.
- Chronic Villainy
All attempts at a genuine Heel-Face Turn are unsuccessful.
- Corrupt the Cutie
The gentle, sweet, and kind Alice begins a slow creep toward the dark side, losing what made her appealing in the process.
- Darker and Edgier
A "gritty" reboot turns a formerly strait-laced hero more grey and Anti Heroish.
- Derailing Love Interests (sometimes)
The author turns Bob evil in order to facilitate Alice's relationship with Charlie (see Demonization).
- Despair Event Horizon (sometimes)
Bob abandons his ethics because he has lost all hope.
- Dirty Cop
A man with a badge turns against the people he swore to protect and serve.
- Drunk with Power
A normally level-headed character gets a taste of power and becomes a Jerkass.
- Et Tu, Brute?
A hero's loved ones, particularly his friends, have all turned their backs on him.
- Evil Former Friend
A hero's best friend is now his worst enemy.
- Face-Heel Turn
The general trope for any morality switch from good to evil.
- Faith Heel Turn
Alice crosses the Despair Event Horizon after learning that her religious beliefs are false or mistaken.
- Fake Defector
Appearing to go evil (or good) without a real morality change.
- Fallen Hero
A once-respected hero turns evil, which often sets up a Cry for the Devil.
- Forced Into Evil
Alice does evil deeds because someone or something else is giving her no other choice.
- Go Mad from the Revelation
A character driven insane because he saw something humans were not meant to see often loses his morality in the process.
- He Who Fights Monsters
Mentally steeling yourself to fight evil might destroy your ethics.
- If You Kill Him, You Will Be Just Like Him
Bob will not kill his enemies because that would make him a killer too.
- If You Taunt Him, You Will Be Just Like Him
Bob refuses to get back at a bully or a Jerkass because that would make him no better than they are.
- Jumping Off the Slippery Slope
A character goes evil very quickly after doing some warned-against but otherwise innocuous thing.
- The Killer In Me
One of the protagonists has been the villain the whole time — which can be as much of a shock to him as to everyone else.
- Knight Templar
An evil character is firmly convinced he is on the side of Good.
- Lawman Gone Bad
A character whose job is to uphold the law goes lawless himself.
- Love Makes You Evil
Nothing throws off Bob's moral compass like the existence of another person for whom he would do anything (related tropes are Love Makes You Crazy and Green-Eyed Monster).
- Moral Event Horizon
The moment when Alice loses the audience's sympathy forever by doing something unforgivably evil.
- More Than Mind Control
Bob did something evil because of Brainwashing but he also did it willingly, if only slightly.
- Not Brainwashed
Bob did something evil because of "Brainwashing," but then we find out he was acting on his own free will the entire time.
- Not-So-Harmless Villain
A comedic, laughable villain is revealed to be much more threatening than she originally seemed.
- The Paragon Always Rebels
Where even a savior figure can become evil, because of the drama inherent in that.
- Peer Pressure Makes You Evil
When Bob's morally shady friends influence him to lower his own moral standards.
- Protagonist Journey to Villain
Surprise! That innocent fellow you were following from the start is now a villain.
- A Pupil of Mine Until He Turned to Evil
The lament of a mentor figure who had a student who used to be good, but no longer.
- Reforged into a Minion
Forced to abandon your friend Alice? Now the Big Bad has twisted her into his Dragon.
- Revenge Through Corruption
Where a villain gets revenge on Bob by making his loved ones evil, insane, and/or under her control.
- Rival Turned Evil
A once-respectable, if persistent, opponent gradually becomes more evil, turning their existing antagonism/competition into something more serious.
- Ron the Death Eater
Demonization renders a heroic character evil in order to suit the author's purposes.
- Sudden Sequel Heel Syndrome
A heroic character becomes an outright villain in a sequel to a work.
- Rogue Protagonist
The heroic protagonist of another story is now the antagonist in this one.
- Start of Darkness
The tale of a character's slow but inevitable plunge into black villainy. Often this is the backstory of someone we already know as a villain, making his alignment change a Foregone Conclusion.
A normally morally-upright character is shown to be indulging in some evil behavior, but it's just to shock you into buying the issue.
- Then Let Me Be Evil
Treat Bob like a villain long enough and he'll decide he might as well become one.
- Took a Level in Jerkass
A once-gentle and kind-hearted character turns into a rude and callous Jerkass.
- Trapped by Gambling Debts
A character is forced into serving the one who holds his debt, often a criminal organization who makes him do their dirty work.
- Villain Corner
A character, not quite a Heel yet, is rapidly being pushed in that direction.
- We Used to Be Friends
Two friends become enemies after one of them turns into a Heel.
- What the Hell, Hero?
The story calls Bob out for doing something morally shady. Unless he heeds the warning and immediately takes steps to correct his behavior, this is often the first step towards a full Face-Heel Turn.
- With Great Power Comes Great Insanity
Alice gains enormous power at the cost of her sanity, which usually means the loss of her morality too.
- Well-Intentioned Extremist
Bob has noble goals but takes ignoble actions to accomplish them.
- Who's Laughing Now?
A Butt Monkey or The Woobie turns evil in order to get respect or take revenge on his tormentors.
Evil to Good
- Adopt the Dog
A character with no real stake in the fight takes an interest in Team Good.
- Neutral No Longer
The general trope for any morality switch from neutral to good or neutral to evil.
- Awakening the Sleeping Giant
The heroes or villains do something to arouse the enmity of a powerful but neutral faction.
- Heroic Neutral
A hero who would just as soon be left alone becomes involved in the plot.
- Default To Good
If the plot comes down to whether an unaligned loner will choose Team Good or Team Evil, he will almost always choose Team Good.
A solitary character becomes a member of a group of friends/allies.
- Adaptational Heroism
A nasty character is changed to a good guy in an adaptation.
- The Atoner
A villainous character turns good in an attempt to make up for the pain she caused while evil.
- Author's Saving Throw
The author steps in to correct a bit of character development. (This can go either way, but evil to good is more common).
- Befriending the Enemy
A good character tries to become an evil or antagonistic character's friend to act as an emotional crutch for them and turn them good.
- Being Evil Sucks
An evil character realizes that being evil is making him miserable.
- Break the Haughty
A proud character gets some much-deserved comeuppance and learns humility, becoming a kinder person.
- Character Check
The writer reminds us that a villain (or hero) slowly drifting towards the opposite alignment has not officially switched sides.
- Comes Great Responsibility
Alice gains vast power and then develops a correspondingly large sense of obligation to use it for good.
- Conspiracy Redemption
When a Knight Templarish (or just plain assholish) organization as a whole goes from evil to good, or at least to A Lighter Shade Of Gray.
- Contagious Heroism
When the hero's morality rubs off on his less scrupulous co-worker (contrast Peer Pressure Makes You Evil).
- Curiosity Causes Conversion
"What's the good guy got that makes him so special? I must find out."
- Defeat Means Friendship
The defeat of a villain causes him to change his evil ways, often to take up the heroes' way instead.
- Defeat Means Respect
The defeat of a villain causes him to develop a healthy respect for the hero, even if he doesn't change his ways.
- Defector from Decadence
When Alice defects from Team Evil because she no longer finds it satisfying.
- Deliver Us from Evil
A villain switches to Team Good because she's pregnant and does not want her child to end up like her.
- Diminishing Villain Threat
An ordinary villain has been foiled and humiliated so often that he doesn't seem all that evil anymore.
- Draco in Leather Pants
The fanbase or an in-universe crowd sees the character as a hero, but it's all in their minds.
- Easily Forgiven
Other characters don't hold the villain's misdeeds against him.
- Even Mooks Have Loved Ones
A villainous underling defects to protect people she cares about.
- Even Evil Has Standards
There are lines even a villain won't cross.
- Face Realization
A supposed villain realizes she's actually a good person.
- Forgiven, but Not Forgotten
The villain is forgiven this time, but he's reminded he won't be if it happens again.
- "Get out of Jail Free" Card
A villain who has reformed is spared the punishment she rightfully deserves for former misdeeds.
- Go and Sin No More
A villain realizes the error of his ways and prepares for punishment from the hero. Instead, the hero lets him go and tells him to atone for what he's done.
- Good Feels Good
A villain learns that being good leads to greater happiness.
- Heel-Face Brainwashing
The heroes use mind control or similar devices to turn an evil character good.
- Heel Face Mole
A villain fakes his or her conversion; essentially the inverted Fake Defector.
- Heel Face Return
A character who left the story as a villain returns as a hero.
- Heel-Face Turn
The general trope for any morality switch from evil to good.
- Heel-Faith Turn
Religion or a religious experience turns a character from evil to good.
- Heel Race Turn
An entire race of people goes from evil to good.
- Heel Realization
An evil character admits (if only to herself) that her actions are evil.
- Ignorant Minion
A minion who is clueless about his employer's true villainous nature, and who may jump ship at once when the truth is out.
- In Love with the Mark
"I was sent to destroy you, but I just couldn't do it."
- Karma Houdini (sometimes)
A villain who escapes the consequences of his villainy might step back and reevaluate his life.
- Kill Me Now or Forever Stay Your Hand
The hero offers his antagonist a chance to kill him, knowing the other person isn't so far gone as to commit murder.
- Little Brother Is Watching
A villain converts because she doesn't want someone who looks up to her to also become a villain.
- Love Redeems
The hero's unconditional love for another makes her change her evil ways.
- Defecting for Love
A female character who's on the evil side falls in love with the hero and joins his side.
- Minion with an F in Evil
A Mook who simply doesn't know how to be evil, even if he wants to be.
- Mook-Face Turn
The villain's loyal followers become the hero's loyal allies.
- Mistreatment-Induced Betrayal
The villain's loyal followers defect to the hero after the villain makes it clear he doesn't care what happens to them.
- Monster Adventurers
Creatures who are generally disposable Mooks decide they want the Plot Armor that comes with being a hero.
- Must Make Amends
A character who has done an evil act seeks to make it right.
- My God, What Have I Done?
A character's Heel Realization delivers a weight of remorse, which may drive her toward the path of atonement.
- The Pardon
Bob's past misdeeds have all been forgiven and forgotten. Will he decide now is the time to leave his old life and start over as a good person?
- Power of Trust
After seeing that the hero trusts her, the villain decides she wants to live up to that faith.
- Rape Portrayed as Redemption
Characters who are raped automatically have a change in their behavior.
- Redemption Demotion
A character who is overwhelmingly powerful as a villain becomes merely average as a hero.
- Redemption Earns Life
Convert and live.
- Redemption Equals Affliction
Convert and suffer crippling injury or a huge loss.
- Redemption Equals Death
Convert and die, but at least you won't die evil.
- Redemption Equals Sex
Convert and you'll get some.
- Redemption in the Rain
Convert and let the rain metaphorically wash you clean.
- Redemption Promotion
A comedic, ineffectual villain becomes a Badass once they start fighting for good.
- Redemption Quest
A former villain accepts an Impossible Task or other difficult quest in hope of earning forgiveness.
- Reformed, but Not Tamed
A character joins the side of good while retaining his villainous qualities.
- Reformed, but Rejected
A villain seeking redemption finds that no one trusts him.
- Reformed Criminal
A former expert in law-breaking now spends his time catching lawbreakers.
- Restored My Faith in Humanity
A character who believes that Humans Are Bastards soon comes to the realization that they aren't.
- Rivals Team Up
Two opponents (neither of which may be truly evil) join forces against a more villainous threat.
- Screw This, I'm Outta Here!
A villain's less-evil forces decide the master's evil cause isn't worth dying for.
- Sex Face Turn
Sex with the hero converts the villain to the side of good.
- Symbiotic Possession
A demon (or any other sentient force) takes control of a person's body, but the host manages to befriend him, turning him into an ally.
- Tears of Remorse
An evil character's potential for redemption shows when s/he sheds tears over an evil action.
- Took a Level in Kindness
A once cruel and unfriendly character becomes a Nice Guy.
- Villainous BSOD
A villain overcome with the weight of his/her evil deeds may become a hero to atone for them
- Welcome Back, Traitor
A character who betrayed the team is Easily Forgiven.
- What Is This Thing You Call Love?
A villain feels love for the first time and is shaken out of his/her evil ways.
- White Sheep
A good character has difficulty fitting in with his evil family, and often turns against them.
- Worthy Opponent
When the hero and the villain begin to operate more-or-less from the same side, while remaining rivals.
The alignment change of an individual character may be caused by (or have repercussions on) his/her relationship with others.
where an alignment shift should
occur but does not
- Enemy Mine
Even though the villain came and saved the day, it was only a temporary thing not caused by a change of heart.
- Easy Road to Hell
In universes with this in effect, it's impossible not to be defined as "evil".
- The Farmer and the Viper
A character is set up to be redeemed through kindness or The Power Of Trust, but it's shown that it didn't work at all.
- Go-Karting with Bowser
("Hey, Skeletor - this is He-Man. Wanna go to the mall this afternoon?")
- Heel Face Door Slam
The villain wanted to reform, but it was too late.
- Heroic Heelization Speech
The hero admits that he doesn't care if his actions are evil.
- Ignored Epiphany
"My God, What Have I Done?... Actually, come to think of it, I've done nothing."
- Kick the Son of a Bitch
A character does something nasty to show how evil they are, but it falls flat because the victim seriously deserved it.
- Neutrality Backlash
A character suffers the ramifications of choosing neither sides.
- Obligatory War Crime Scene
The heroes Kick the Dog (or worse) in an inexcusable way without experiencing a Heel-Face Turn, because War Is Hell and even The Hero can't maintain their goodness throughout it.
- Post Mortem Conversion
A character who died a villain is remembered as a hero.
- Redemption Failure
A formerly-evil character almost reaches redemption... and then stuff happens that forces them back into villainy against their will.
- Rejected Apology
A character's heart-felt apology is rejected by another.
- Slowly Slipping Into Evil
Gradually becoming evil without a marked alignment change.
- Villainy Discretion Shot
A character is saved from Bait the Dog or worse because their evil acts are glossed over by Rule of Empathy.