A story where the narrative splits to cover several separate timelines, usually determined by a single (often insignificant) event near the beginning. (Usually, there are only two, but some works depict more.) This is nearly always done by alternating between each of the timelines, though split-screen may be used for certain segments.
Oftentimes, there will be parallels between the variants; however, the main appeal is seeing how the event causes radical changes in the plot. This can be done for either dramatic or comedic purposes, with the latter generally using more ridiculous diverging points and/or subsequent changes.
Sub-trope of Alternate Timeline and Flash Sideways. Compare "Rashomon"-Style (which depicts different perspectives on the same events), What If? (which examines an alternate timeline in a manner that doesn't necessarily overtake the main plot), Missed the Bus (which may examine the consequences of a character missing their bus in a similar fashion), or Two Lines, No Waiting (if it only uses two timelines). Contrast "Groundhog Day" Loop (where time keeps repeating regardless of one's actions).
Examples:Anime & Manga
- Dual! Parallel Trouble Adventure: The Cold Open of the series involves a man named Yotsuga finding some piece of alien technology. His supervisor orders him to throw it into the trash, and immediately the screen splits into two scenes: one of Yotsuga trashing the artifact and another of him keeping it. The story thus deals with the descendant of Yotsuga, Kazuki, living in the world where the artifact was trashed but being able to see visions of the parallel world where it wasn't, where wars are now fought using Humongous Mecha.
- House of X / Powers of X has this as part of a Plot Twist. The Powers of X issues are split between four time periods: X0 (takes place in the past), X1 (takes place concurrently with House of X), X2 (takes place a century into the future, where mutants are at war with the humans and machines), and X3 (takes place a millennium into the future, where mutants won the war and are the dominant race). It initially seemed that the future time periods were part of the same timeline as the past and the present, until the end of Powers of X #3 revealed that the future we've been seeing is part of a prior life of Moira MacTaggert — specifically, a life where she allied herself with Apocalypse instead of Professor X.
- With This Ring: Because it is based on comics, The Multiverse is a thing, but two timelines are given primary attention, and their first divergence is if they wanted Alan Scott along when they meet the Young Justice team. The timelines are often called Paragon and Renegade (due to the appearances of the Mass Effect symbols).
- Sliding Doors is the Trope Codifier (often being referenced by other works using this trope) - the film switches between a timeline where the main character makes her train and a timeline where she barely misses it.
- Mr. Nobody is about a boy that lived all possible futures. While the movie jumps between several main branches, the initial diverging point is which parent he goes with at the train station.
- Run Lola Run: Manni works for a crime boss and accidentally leaves 100,000 marks on the subway where it's stolen by a homeless man. He's dead if he doesn't bring it in, so he decides to rob a grocery store in order to get the money elsewhere. He informs Lola about this 20 minutes beforehand. Lola, whose father is a wealthy banker, decides to see if she can get Manni's money for him. In three different loops, she goes to the bank, asks for the money and decides to rob/not to rob it. Manny robs/doesn't rob the store and Lola wins/doesn't the money in a casino. Also, Manni does or doesn't retrieve the money from the homeless guy.
- The Post Birthday World by Lionel Shriver switches back and forth between a timeline in which the protagonist stays with her long-term boyfriend and one in which she leaves him for another man she had dinner with in the prologue. The book follows the many different ways each man impacts on her life after this point, often covering the same event (e.g. a dinner with her family) but with the differences highlighted. Unusually, it ends the same way in a shared epilogue: at the end of the story she breaks up with one man and the other dies, so she is left single at that point regardless. Naturally, she thinks that she made the right decision either way.
- Terry Pratchett's Jingo: Commander Vimes drops his Dis-organizer box, and accidentally picks up one from a parallel universe. He experiences a downplayed example of this trope as he hears about what would be happening to his officers if they had stayed in Ankh-Morpork instead of going to Klatch. He's horrified to hear that they'd all die.
- Frasier has "Sliding Frasiers", whose name is a Shout-Out to Sliding Doors. In it, Frasier must decide whether to wear a sweater or a suit to a speed dating event. In the former, he has an awful time, while in the latter, he indirectly finds a date but ends up putting her off. Either way, he ends up driving home alone.
- The Malcolm in the Middle episode "Bowling" splits between Hal and Lois taking the kids out to bowl. When Hal takes them, Malcolm has a good time and attracts the attention of a pretty girl, Reese fares poorly at flirting and attracts the ire of another patron, and Dewey (staying home) is unable to get around Lois's strictness. Meanwhile, Lois is overbearing and strict, making for a miserable experience for both brothers; Dewey, by contrast, tuckers out Hal, gets pizza, and watches R-rated movies on TV. The twist is that both timelines invert near the end - Malcolm ends up ruining Hal's perfect game (and Reese gets beaten up by the patron he angered), while the former at least gets a kiss from the girl in Lois's timeline.
- Community's "Remedial Chaos Theory" centers on the main cast attending a housewarming party; when the pizza man arrives, they roll a die to determine which one has to get it. No less than seven timelines are covered, with results ranging from awkward to happy to outright disastrous.
- In the aptly titled Broad City episode "Sliding Doors," we see two versions of the day Abbi and Ilana first met: one in which they miss a train and spend the day together, and one in which they catch the train and go about their separate lives. The audience is led to believe that the first timeline is the "real" one, but it ends with both characters getting hit by a bus, while in the second timeline the girls meet again by chance at the end of the day.
- The American Housewife episode "Sliding Sweaters" has Katie deciding which color sweater to buy to wear for a job interview. The two possible results of buying either one are presented: with the pink sweater, Katie has a good day; with the blue sweater, her day goes horribly. The Stinger shows a third timeline where she gets a green sweater. It ends with her getting pregnant. She then decides to not buy anything and wear something old.
- The Life in Pieces episode "Emergency Colonoscopy Driving Lunch" has Matt trying to get a sperm sample to the fertility clinic in less than 30 minutes. He gets a phone call, and the plot changes depending on who is calling, ending disastrously each time. In the end, he decides to just get his sample taken at the clinic and avoid the hassle.
- This is sort of the main idea in Russian Doll. The fruit rotting overtime proves that the characters are living same day over and over again in different realities rather than the day just restarting.
- If/Then's point of divergence is Elizabeth deciding to hang out with Kate (the "Liz" timeline, where she focuses on romance and family) or Lucas (the "Beth" timeline, where she focuses on her career) at the park when she first moves to New York. The Liz timeline is told in Act I and the Beth timeline in Act II.
- Chrono Cross: The player character, Serge, is somehow brought into an alternate timeline where he died several years ago. The parallel world he comes from (Home World) and the one in which he died (Another World) both have to be traversed throughout the adventure (and, on numerous occasions, people or objects from one world are needed to resolve a problem in another, and sometimes the party needs both at once). The two worlds are very different in numerous ways and there is a bit of conflicting information regarding exactly when the split occurred. Most sources state that it happened at the moment Serge drowned in his world, but an unseen future incarnation of the MacGuffin Girl came back in time to save him. Another source says that it occurred years earlier when Serge first made contact with the MacGuffin Girl four years before that.
- In Worm, this turns out to be Coil's metahuman ability - activating it splits his consciousness between two parallel timelines in which he can take different actions, and he gets to choose which timeline to remain in when it's deactivated.
- The Homestuck Epilogues are split into two timelines, determined by John's choice of meal at the end of the prologue: meat or candy. (This symbolizes the tone of the timelines' events: "Meat" is Darker and Edgier, while "Candy" is lighter and shows the original comic's cast to largely be happy after its conclusion.) This starts changing as the story progresses in two ways. The first is that both timelines ultimately end poorly, with Candy's cheeriness quickly being exposed as a facade and going downhill. The second is that the two timelines are linked in-universe; among other things, several characters are sucked into a black hole in one timeline and end up appearing in the other.
- The Irate Gamer's review of Mario Is Missing and Mario's Time Machine functions this way, with the diverging point being the game he chooses to review. In both timelines, he inadvertently causes a gas leak in his house and Ronnie the Skeleton arrives and asks whether he can watch him play. The only major divergence is the Irate Gamer letting him stay in the former timeline, whereupon he notices the leak and fixes it; the latter timeline ends with him attempting to burn the game and dying as a result.
- Third Rate Gamer: The review of Super Mario Bros. and Super Mario Bros. 2 is a direct parody of The Irate Gamer review of Mario Is Missing/Mario's Time Machine. The titular gamer inadvertently lights a Cartoon Bomb in both timelines, and "Offensive Stereotype" will either save him or leave early. As befitting the series' Stylistic Suck nature, he manages to mix up the two timelines, and "Offensive Stereotype" suddenly appears in the one where he left and fixes the bomb. Lampshade Hanging immediately ensues:
Billy: What the hell is wrong with you?TRG: What are you talking about?Billy: He left in this timeline! It's the other timeline where he stays so he can save your life before your house explodes!TRG: [directly to camera] This video is confusing... I should have been paying more attention.