Alice loves Bob, and Bob loves Alice. But then, it would be too easy if it was this easy: for some reason, Alice and Bob cannot be left to live happy together. Sometimes, this leads to Love Makes You Crazy, when Bob stops acting rationally to stay with Alice. Sometimes, Bob decides to take care of this annoying guy who claims he wants to just be Alice's friend. Sometimes, Alice decides to torture and murder all of Bob's female friends so he won't be distracted by all these, well... Sometimes, Bob coldly decides to sacrifice his True Companions to save Alice.
This is none of these situations. This is when Alice and Bob stay, most of the time, level-headed and genuinely try their best to be together, and notwithstanding their success or failure, the Collateral Damage is at least 147 deaths, the destruction of three cities, and maybe even the End of the World as We Know It. Even if it can involve some irrationality (after all, Love Makes You Crazy or sometimes evil), it's not the characters' flaws, but the circumstances that force the couple to go to extreme lengths to be together. Or, even worse, they didn't even realize what they were doing, and the couple's stubborn insistence on being together results in an unintended ripple effect of death and destruction. In short, this trope is not about characterization, it is about the effects of a relationship on the story and the setting.
Can involve Love Makes You Evil or Love Makes You Crazy. This is an inversion of Destructo-Nookie where the rampage part involves only the couple and usually does not leave the bedroom.
This is a trope about how romance can be really, really destructive. That's just what happens when you place the huge power of love into the hands of someone in love. They become irrational and mad with power. Expect at least one case of Murder the Hypotenuse, especially if there is a Yandere involved.
The Trope Namer is Love Actually, by way of its tagline, though it's not an example.
Related to Love Makes You Evil and Love Makes You Crazy. Also related to Destructo-Nookie and Outlaw Couple. Sometimes caused by Always Save the Girl.
Examples:
- Future Diary: By the end of the series, we learn that Yuno and Yukiteru were once this in another world. When Yuno won the right to succeed Deus Ex Machina in the first world, her first act as the new God was to attempt to resurrect Yukiteru. Needless to say, it did not go well. Everything we know of her in the series is the Yuno who has already long since crossed the Moral Event Horizon by abandoning the first world and creating a second where she could replay her day with Yukiteru. It is heavily implied though that they fit this trope very well in the first world before the events of the series and the original Yukiteru's death.
- In Tsubasa -RESERVoir CHRoNiCLE-, Shaoran causes the time to rewind and a lot of characters suffer because of this, in order to save Sakura.
- Also, in X1999, Kamui's wish to get Fuuma back even if it causes Fuuma and the rest of the world harm. Can also be said for a lot of other characters.
- Umineko: When They Cry: Kinzo and Beatrice (and Beatrice and Battler)
- The second half of Full Metal Panic! has this as a major element when Amalgam starts drastically stepping up their efforts to capture Kaname. Kaname is horrified enough by the collateral damage that she actually surrenders, hoping she can at least stall the plans she's critical for from within. Sousuke, on the other hand, doesn't hesitate to go on the warpath to return his Living Emotional Crutch home; and while Kaname does briefly try to dissuade him and cope without her, she realizes mid-It's Not You, It's My Enemies speech that neither she nor Sousuke can tolerate their separation anymore and that they have no obligation to shoulder the blame for an obscenely powerful terrorist organization that has every reason to just leave her the hell alone. Thus, she commands Sousuke to do whatever he needs to in order to rip Amalgam a new one and get her back home, an order he accepts with a very rare smile.
- In The Sandman (1989), Morpheus and Nada make love once. Her home city is reduced to glass shards. It's suggested that had they remained together, the entire world would have been destroyed.
- Star Wars: A lot of people wouldn't have died if Anakin Skywalker never fell in love with Padme Amidala.
- The Monk: Ambrosio and Matilda, who resort to murder, black magic, and, for Matilda, selling her soul to the Devil.
- Bella and Edward of The Twilight Saga start a war and cause all sorts of chaos and mayhem, including hurting each other, in their quest to be together.
- Haven: Nathan and Audrey. In the mythology of the show, the Troubles are genetic supernatural curses that besiege the town of Haven, Maine for a few years every 27 years. They stop when a mysterious, otherworldly woman arrives who is immune to them; she helps out for awhile and then pulls a Heroic Sacrifice, which ends them for another 27 years. This has worked for the last 500 years. Except this time, when Audrey finds out she is this woman and she and Nathan fall for each other. Nathan is unwilling to let her sacrifice herself, disrupts her Heroic Sacrifice, and unwittingly kicks off the apocalypse. Seasons 4 and 5 see the town turn on the pair of them, because everything Nathan and Audrey do to prevent Audrey's death just make things worse. By the time season 5 rolls around, people are dying daily from the Troubles, and they have had enough—Nathan gets put on trial for his failure to serve in his capacity as the police because of his feelings for Audrey, and barely manages to avoid being executed via vigilante justice.
- Romeo and Juliet's romance causes six deaths. 1: Mercutio: Killed defending Romeo. 2: Tybalt: Killed by Romeo. 3 Romeo's mother: Died of sadness because of Romeo's banishment. 4: Paris: Killed by Romeo. 5: Romeo: Killed by Romeo. 6: Juliet: Killed herself because Romeo did.
- Love rarely ends happily in the operas of Richard Wagner. (Of course, what did you expect in an opera -- a happy ending?) It causes Senta to jump off a cliff, Elisabeth and Heinrich apparently just to keel over, Elsa to betray Lohengrin and then to keel over, Siegmund to commit adultery with his own sister and be killed by her husband (she dies in childbirth), Gutrune to drug Siegfried into loving her so that ''his'' wife kills him and then burns herself to death, and Tristan to get fatally wounded while messing around with Isolde, the king's wife, who then herself keels over. Only Walther and Eva seem to end up well.
- Romeo's and Juliet's neighbors got off easy compared to the citizens of Rome and Egypt in Shakespeare's Antony and Cleopatra when their affair starts a war and turns all their people against them.
- Gwendolyn and Oswald of Odin Sphere, which is very, very loosely based on Wagner's Der Ring des Nibelungen. They meet on a battlefield and between the two of them have stormed cities and literally gone to hell and back for each other. Without even knowing how the other feels.
