So Bob owes Alice big time. Maybe she saved his friend, or did something selfless for him, or risked her life for his, it doesn't matter. The thing is, Bob and Alice aren't friends. They might even be enemies. Where this trope comes in to play is when Bob inexplicably helps out Alice, usually followed by a "Now we're even" from Bob. The key to this trope is that it's a one-shot deal; if Alice gets herself in trouble later it's her problem, not Bob's. Bob may even be the cause of her troubles. Bob might even be helping Alice in advance by his own initiative so she doesn't try to approach him with a You Owe Me scenario, a situation which may force Bob to operate under Alice's potentially unfavorable/undesirable terms.
- One Piece: The male Vinsmokes to Sanji, whose compassion is the only reason they survived an assassination plot. After Sanji saves the Vinsmokes from the Charlotte Family, Judge finally agrees to respect Sanji's choices and leave him alone, but only because he doesn't want to owe Sanji anything. The Vinsmokes later help the Straw Hats escape, first from the Whole Cake Chateau, and then from Cacao Island. Subverted with Reiju, who is genuinely grateful to Sanji for both proving there was still compassion in their family and for saving her life.
- Yu-Gi-Oh!: Kaiba claims that Tea helping Mokuba escape from the Rare Hunters is the only reason he's helping Yugi find his friends. Then he uses it as his reason for saving Tea's life. Considering all the times he makes a point of explaining how he's only "helping" the gang out of selfish reasons, it's pretty easy to say it's only a shield for his Hidden Heart of Gold.
- In Arakawa Under the Bridge, the protagonist has always lived by this principle, paying all debts as quickly as possible, but he finds himself in a quandary when a crazy woman who lives under a bridge saves his life.
- Elfen Lied: Thoroughly despicable man he may be, but one of Bandou's policies is to repay any debts he owes. When he learns that Mayu is responsible for saving his life in an earlier fight, he gives her his phone number and tells her to call him if she's ever in trouble. In the manga, he makes good on this promise by saving Mayu from being raped and killed by The Unknown Man.
- In chapter 55 of Kaguya-sama: Love Is War, Kaguya helps Ishigami to study for his exams when she finds out that he's in danger of failing since he had helped her out in the previous chapter. Given that Ishigami was terrified of Kaguya at the time, he spends most of the chapter convinced that she was trying to torture him.
Kaguya: I dislike owing debts. I was raised with the belief that when you owe a debt, it should be repaid as quickly as possible.
- ElfQuest: This is ostensibly Rayek's reason for helping Leetah to save Cutter's life after the disastrous battle with the snow trolls. In reality he probably did it out of compassion, though he'd never admit it.
- This is one of Lucifer's defining characteristics, as expected by someone who defines the sin of Pride and hates being dependent on anyone. Meleos at one point notes that he has taken his revenge in one of the ways that will rankle Lucifer the most by being responsible for saving his life, and the ending implies Lucifer's main problem with God is that, having been created by the latter, he is dependent on God in a way he can never repay.
- Loki in The Sandman turns out to have... strong views. To the point that he only repays it by accident, while trying to kill the one he owes.
Loki: I am Loki. And I will be under an obligation to no one.
- Ripples, Waves, Tsunamis: A severe understatement for Raijax when he hears about everything Luffy had done: beating Arlong, beating Hody, burning Enies Lobby to the ground, punching a World Noble in vengeance for a fishman, to save a mermaid, breaking Jinbe out of prison, diverting Big Mom's wrath from Fishman Island, and most recently, saving Nami from his berserk rage. He's extremely grateful, sure, but that just makes him more furious; he considers himself to have a mountain of debt to pay back, and he just met him!
- Shang in Mulan spared the title character's life after she dishonored the Chinese army, in return for her saving his life during the Huns' attack.
Shang: A life for a life. My debt is repaid.
- In Constantine, Satan appears to be one as he did not like owing Constantine a favor for getting him to save the world from Satan's son. The debtor does find a price Constantine is willing to accept, then regrets it.
- In Little Big Man, Jack saves the life of his enemy Younger Bear. Years later, Younger Bear saves Jack's life at the Little Big Horn. He then tells Jack that he's planning to kill Jack the next time they meet.
- In "The Goblin Wood" by Hilari Bell, that's how Makenna allies with the goblins. Their entire culture is based around paying back debts, and when she frees a goblin she finds she is stuck with a helper. It works out well for them, in the end.
- The Hunger Games:
- Thresh spares Katniss' life because she had been nice to Rue.
- Katniss herself is an example of this trope: when The Hunger Games starts out, she hates Peeta because he defied his mother and gave her bread when she was starving. After Thresh saves her, she thinks:
Katniss: I nod because I do understand. About owing. About hating it.
- Discworld book Carpe Jugulum says that this is a key part of witch psychology and that if you really want to hurt a witch, then you need to do her a favor she has no way of repaying. The unfulfilled debt will always nag at her.
- The faeries in The Dresden Files, although it's not so much that they dislike being in debt as that if someone helps them, they're compelled by their nature to render aid in return, so they're irritated by open-ended obligations.
- In Harry Potter, James Potter saved Snape's life and it's implied that Snape protects Harry because he regrets not being able to save James' life in return. Or at least that's the story in the first few books, until it's revealed that he also loved Lily.
- Harry also saves Peter Pettigrew's life in the third book, by convincing Sirius to turn him in to the authorities instead of killing him. Dumbledore tells him this puts Pettigrew in his debt. This doesn't stop Pettigrew from helping set him up as a sacrifice to Voldemort, but does cause him to hesitate when he has the chance to kill Harry directly, which ends up saving Harry's life as it causes Peter's cursed silver hand to strangle him to death.
- Uncle Hoole of Galaxy of Fear is usually fine with owing people... but he hates to owe Jabba the Hutt, because Jabba always calls in favors. As a shapeshifter Hoole would make an excellent spy or assassin, but he's adamantly against doing that. Which doesn't mean he's not forced to ask for Jabba's help.
- Raistlin from Dragonlance is not altruistic (except in certain very specific circumstances) but he hates the idea of being dependent on another person and as such if he feels he's in your debt he will repay you, with a good turn he feels is exactly equivalent in value to what you did for him — indeed, the last few chapters of Dragons of Spring Dawning is basically an extended sequence of him paying off all his debts to the other protagonists so he feels can go his own way in peace. Later on, he trains his apprentice Dalamar to believe this as well.
- Peter from Divergent. After bullying Tris mercilessly and molesting her, he saves her life in Insurgent because she saved his. Tris absolutely does not understand his perspective. Not at ALL.
- Spinning Silver: The Staryk Fair Folk insist on honouring every bargain and can't stand to be unable to repay a debt, so much so that the wounded Staryk King refuses life-saving aid until they agree on a fair price for it — he'd rather die than be irrevocably in debt to someone.
- Shran on Star Trek: Enterprise, vis-a-vis Archer. When Archer helps to reveal that the Vulcans are spying on Andoria, Shran's last shot before leaving is a pissed-off statement acknowledging that he owes Archer. He later turns up to bail them out, repaying the debt and then some—the two of them go back and forth with owing each other until a Fire-Forged Friendship evolves.
- In Star Trek: The Next Generation, Q. In one of the early Q episodes, Picard shelters Q after Q has been made mortal temporarily. Q hates that he owes Picard a favor and tries to get Picard to name a favor so he can resolve the obligation. Of course, Picard knows that Q is The Trickster and a Literal Genie and refuses to accept repayment. Q's response is to make up a need of Picard's and "solve" it for him in an incredibly roundabout and dangerous way.
- In an episode of the Buck Rogers in the 25th Century TV series, Buck saves the life of Tigerman (Princess Ardala's bodyguard). Later, Buck is about to be executed and Tigerman threatens the Princess until she releases Buck. As Buck starts to leave, he asks Tigerman if he will be coming along (implied that they are now friends). Tigerman simply replies, "I owed you a life. We are now even," as he then warily looks at the Princess.
- Part of how Todd the Wraith manages to survive so long on Stargate Atlantis; he and Sheppard keep saving each other's lives.
- Averted in Stargate SG-1:
- SG-1 lets Nirrti go after she saves Cassandra's life. Nirrti is surprised, and mentions that, if the situation was reversed, she would not be so generous. Later on, Nirrti captures SG-1 and, when reminded of the incident, reminds them her words
- Additionally, when Carter saves Cronus's life (he was attacked by Nirrti using an Invisibility Cloak), they offer him the identity of his attacker in return for letting Earth keep both of its stargates. As Cronus and Yu lead Nirrti away, Cronus lets the Tau'ri know that his debt is now paid and that they should not expect mercy if he catches them again. And no, he doesn't show them any when he catches them (or those he thinks are them).
- Sheldon in The Big Bang Theory takes this to ridiculous levels. He absolutely despises being given a gift because he overthinks everything and spends too much time trying to exactly match the financial and emotional reciprocity. He also generally dislikes being in debt to his "friends" because he considers them beneath him, part of his Jerk with a Heart of Gold persona.
- When Dietrich saves Harris's life in Barney Miller, Harris is pissed because Dietrich annoys him so much and goes to increasing lengths to repay him, which Dietrich refuses until Harris writes him a check... but that's only so he can flush the check down the toilet.
- A dark variant in Knights of the Old Republic II: The Sith Lords; the Bounty Hunter Mira had spared the life of Hanharr, a Wookiee bounty hunter who had been trying to kill her, but got caught in his own trap instead. Wookiee culture demands that if someone saves your life, you are obliged to pledge your life to them. Hanharr hates Mira and despises the Life Debt, meaning he would like to find a way to get her killed just to be free of the obligation.
- Entry 68 of the Evil Overlord List states: "I will spare someone who saved my life sometime in the past. This is only reasonable as it encourages others to do so. However, the offer is good one time only. If they want me to spare them again, they'd better save my life again."
- From Gargoyles, after Macbeth helps Demona kill Gillecomgain:
Demona: Thank you.
Macbeth: I owed you.note
Demona: Then we're even; good.