Massive Multiplayer Crossover / Literature

• Science Fiction author Philip José Farmer:
  • The Wold-Newton universe includes scores of public domain characters as well as many characters popular from early Radio Drama and film, such as The Shadow and Tarzan, who are not quite out of copyright. Fans have added many modern TV characters to the list.
  • The Riverworld series does this with actual people from history.
• Kim Newman does this a lot, most notably Anno Dracula, which features just about everyone.
  • His novella Teddy Bears' Picnic is about Terry and Bob of the British sitcom The Likely Lads fighting in the Vietnam war with William of Richmal Crompton's old Just William stories and other fictional characters.
  • The student rosters appearing at the end of his Drearcliff Manor subseries indicate that his weird boarding school attracts everyone from young Time Ladies to future members of The Addams Family.
  • Angels of Music transfers the premise of Charlie's Angels to the 19th century, with The Phantom of the Opera as Charlie and a rotating cast of heroines from the sensational fiction of the period as Angels, and various other period characters as clients, friends, or adversaries.
• Silverlock by John Myers Myers, in which the protagonist A. Clarence Shandon is shipwrecked in the Commonwealth of Letters, where everywhere he goes and everyone he meets is a literary, mythical and/or historical reference. A fairly extensive list of specific references can be found here.
• Robert A. Heinlein's The Number of the Beast features a Time Travel device that does double duty as a portal into The Multiverse, allowing his characters to visit every fictional universe ever, including all of Heinlein's own novels. They coin the term "World as Myth" to describe the Recursive Canon necessary to make this work, and wind up hosting a convention for just about every Science Fiction character ever.
• Spider Robinson's Callahan's Crosstime Saloon series - including Callahan's Lady - contains cameos from characters created by crime writer Donald E. Westlake, SF legend Robert Heinlein, and even classic British humorist P. G. Wodehouse, all interacting with each other. (Most likely inspired by Heinlein's The Number of the Beast, mentioned above.)
• Simon R. Green's Nightside take place in a secret city under London that's a giant crossoverfest. John Taylor, Green's protagonist, has met characters from all manner of books, movies, television shows, and other assorted places though they are largely referred to in vague, shadowy terms so he doesn't violate the copyrights too badly. There's everything from a Traveling Doctor who had a trick with celery to having to exorcise Kandarian demons from his answering machine to giant 'bears of little brain' that work for the auction house. For even more fun, representatives from most of Green's other series (the Deathstalker novels, the Darkwood books, etc) show up, waiting around to speak to Father Time.
• While Neil Gaiman's short story A Study in Emerald is primarily a crossover between the works of H. P. Lovecraft and Arthur Conan Doyle, it contains subtle hints that characters such as Dracula, Frankenstein, and Dr. Jekyll also exist in the same universe.
• Roger Zelazny took a few stabs at this trope:
  • A Night in the Lonesome October features Jack the Ripper, Sherlock Holmes, Dracula, Frankenstein, Rasputin the Mad Monk, The Wolf Man (1941), and many others in a complex game determining whether or not Cthulhu and the other elder gods return to Earth. Interestingly, Jack is the hero...
  • Zelazny was a comic book reader and fan. In Blood of Amber Merlin has dinner at Bloody (Last Deceased Owner's Name)'s place—Bloody Andy's at the time—while a gent (with a pronounced scar through his eye) eats at a neighboring table and warns Merlin to show a blade so the local roughs get no ideas. "Old John" was clearly John Ostrander and Tim Truman's mercenary John Gaunt (aka Grinner, Grim Jack) from Cynosure, a cross-dimensional city in a multiverse adjacent to Amber. The two roughs did not last the night.
  • A later Amber short story by Zelazny features Corwin visiting Wildwood Cemetary, where he sees the graves of John Gaunt, Denny Colt and Remo Williams.
• Stephen King's The Dark Tower series spans across the majority of his prior works.
• The Harold Shea series of short stories are about Harold and company visiting various settings taken from mythology and public domain fiction, usually one per story.
• Brazilian author Monteiro Lobato took this trope to insane levels in his kid's books set in the Yellow Woodpecker Farm. The eponymous farm is an interdimensional nexus to, essentially, every fantasy and adventure fiction character ever written, including but not limited to the Greek Gods, Sherlock Holmes, the Neverland people, the Arabian Nights, the fables from Aesop, Grimm, Andersen, The Three Musketeers, medieval Knights, etc etc etc ad infinitum. He even managed to throw in some characters copyright laws didn't allow him to. To top if off, characters native to the series' own universe are not few in number.
• Jasper Fforde's like this trope a lot. Pretty much every Bookworld character in the Thursday Next series comes from another book. According to the rules of its universe every book crosses over with it. Including itself. Many of the characters from the Nursery Crimes series are right out of nursery rhymes.
• L. Frank Baum did this in the fifth book of the Oz series, The Road to Oz, by inviting characters from his other books to attend Princess Ozma's birthday party, hoping to get his Oz readers interested in those other non-Oz stories. This included everybody up to and including Santa Claus (as in The Life and Adventures of). The implication, of course, is that every book Baum ever wrote takes place in the same universe as the Oz books.
• James A. Owen's The Chronicles of the Imaginarium Geographica does this with pretty much every major work of fantasy, history, and real life. From King Arthur to C.S. Lewis to Greek Myths all in 1 epic tale spanning time travel, history and all western literature.
• In Alethea Kontis's Enchanted, multiple fairy tales are true, from the red shoes that dance Tuesday to death, to Monday being the princess in the Princess and the Pea, to Sunday's meeting up with the Frog Prince, and the whole family living in what was once Rapunzel's tower.
• In E. D. Baker's The Wide-Awake Princess, Sleeping Beauty's younger sister is wary because of the tale of Little Red Riding Hood, meets up with Hansel and Gretel at the witch's, etc.
• The Breath of God, a Sherlock Holmes pastiche by Guy Adams, has Holmes needing supernatural assistance, and teaming up with Aleister Crowley, Carnacki the Ghost-Finder, John Silence and Julian Karswell.
• L. Jagi Lamplighter's Rachel Griffin is based on a role-playing game of this. For rights reasons, it's all Expys now, but the originals are frequently detectable. Such as the original of Vladimir von Dread.
• David Weber wrote a joke ending for Safehold that makes it a crossover with Empire from the Ashes, The War Gods, Bolo, In Fury Born and Battlestar Galactica (all of which it has at least some thematic parallels with).
• Ask a Policeman is a Round Robin by members of the Detection Club (specifically John Rhode, Helen Simpson, Gladys Mitchell, Anthony Berkeley, Dorothy L. Sayers, and Milward Kennedy) in which Lord Peter Wimsey, Mrs Bradley, Roger Sheringham, and Sir John Samaurez investigate the same murder, with the further twist that the authors have swapped detectives.
• Superfolks has the DC Comics superheroes and villains though most of the heroes have since died. There's mention of Invasion Of The Bodysnatchers being a documentary and Peter Pan and Kojak make cameos, among others.

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