A "shared world" or "shared universe" refers to a single shared setting used for fiction, like the Marvel Universe or Cthulhu Mythos. In this fandom, a shared world is a fanfiction setting used by two or more authors; this is seperate to one author writing a sequel to anothers, as setting is primary rather then original story, or to a shared character.
There may often be a bible outlining the basics and specifics of the series: where it takes place, what differences exist between this world and the canon Dariaverse, which characters can be used, what rules and guidelines should be considered, and so on.
The very first original shared world for Daria was the offbeat comedy series, Abruptly Amy, coordinated by Kara Wild and contributed to by numerous authors and artists. Abruptly Amy was highly successful and ran through the year 2000, with a few additions coming later.
Shared worlds became increasingly more common after the show ended, before dying out more-or-less in the mid-2010s as fandom changed.
Some unsuccessful attempts of Shared Worlds have happened: The Angst Guy attempted to start Lovestruck Alien Teenage Invaders from Mars, a sci-fi comedy, and Shining Star, a dystopia about a supernova. When comparing Lovestruck to his more successful Daylight, TAG suggested that the failure of LATIFA is either a less attractive bible or "Was comedy less appealing than drama and angst and The End of the World in a Different Way?" - and certainly, for the most part shared worlds love their drama and angst more than comedy, unlike Abruptly Amy.
So far, five shared worlds have had enough writers and works to count as 'major'.
If you want to read them on PPMB, you'll have to use the "Rosetta Stone" to get around unicode issues.
- Abruptly Amy faked up a spinoff about Amy Barksdale, pinging off the fact she'd only been in two episodes then and given a "Saint Amy" fanon persona. The central gag at the start was Alan Smithee created this spinoff with no clue about the original show. It caught on with the big-name fans of the time like C.E. Forman and Michelle Klein-Haas, and rapidly expanded into from a fake description into a full fake 'series' - complete with "Outpost Amy" fansite - with Amy as a glamorous FBI agent forced to take refuge in her home town to escape the mob.
- Legion of Lawndale Heroes, with the Daria cast granted superpowers, was the second shared world in 2007, when Brother Grimace continued the superhero series begun two years earlier by Roentgen. About a half-dozen authors have since contributed stories to the collective anthology, with a number of side anthologies: Legion of Lawndale Heroes Minis (one-shot "mini-episode" short stories), LLH: Daylight (the events of the Daylight shared-world series as experienced by the Legionnaires), and Legion of Lawndale Heroes: Alternate Future (a Tiffany-centric series by Psychotol).
- Tales of the Ringbearers, featuring the pan-dimensional Ringbearers rather than start from an existing body of work, jumped off from a brief section in one of Doggieboy's science-fiction tales ("A Little Vacation," from January 2008), then spread in all directions from there. At least eight writers have now contributed to this shared world, and the Ringbearers have shown up in other shared worlds.
- Daylight (invented by TAG sprang from a plot-line bible and not from a previously written story. Across a number of universes, the Sun becomes violently eruptive and severely damages human civilization. Writers were each encouraged to pick out their favorite Dariaverse (or create a new one) and follow the events outline in the story bible. *Many Daylight stories are crossovers with the other two shared-world settings.)
- The Judith Saga, a shared-world series created by Erin Mills in May 2010 and anchored by the shared-world trilogy of 'Judith Strikes!', 'Worldburner' and 'Worldhopper': a horrifically powerful and sociopathic alternate Daria, naming herself Judith, wreaks bloody havoc across the entire multiverse. Over a dozen writers ended up contributing across its run, (Worldhopper is exclusively written by Erin but is tied in to the previous two, open-to-all series.)
A number of settings were shared between several writers:
- Lawndale's Finest, a superhero series by NightGoblyn, became a shared world in March 2010 when Jim North began writing for it.
- The "punkverse", formed from Brian Taylor's Moving Pictures and Charles RB's God Save The Esteem, was created in August 2010. A sliding timescale has Helen and Jake as 80s punks instead of 60s hippies (and remaining punks in 2010), and Amy as a young sci-fi/fortean fangirl with an obsession with filming everything (who works for Sick, Sad World in the present day).
- "Invertedverse" is the name of a shared universe created by Shiva from a short scene that should not be in which the personalities of the characters in the Dariaverse are inverted, ie Daria is obsessed with fashion and popularity, Quinn is a misanthrope, etc, and along with a completely inverted cast.
- LongSnakeMoan's Of All The People That Won't Be Missed (inspired by the film Natural Born Killers, with Jane Lane and Todd Ianuzzi as expies of Mickey & Mallory) has also inspired several other writers to contribute their works and to create in-universe 'tweets' that were sucked into the main narrative.