Retroactive continuity, or retcon for short, is a literary device in which established diegetic facts in the plot of a fictional work are adjusted, ignored, supplemented, or contradicted by a subsequently published work which recontextualizes or breaks continuity with the former.
The Hitchhiker's Guide to the Galaxy is a comedy science fiction franchise created by Douglas Adams. Originally a 1978 radio comedy broadcast on BBC Radio 4, it was later adapted to other formats, including stage shows, novels, comic books, a 1981 TV series, a 1984 text-based computer game, and 2005 feature film.
The Foundation series is a science fiction book series written by American author Isaac Asimov. First published as a series of short stories in 1942–50, and subsequently in three collections in 1951–53, for thirty years the series was a trilogy: Foundation; Foundation and Empire; and Second Foundation. It won the one-time Hugo Award for "Best All-Time Series" in 1966. Asimov began adding new volumes in 1981, with two sequels: Foundation's Edge and Foundation and Earth, and two prequels: Prelude to Foundation and Forward the Foundation. The additions made reference to events in Asimov's Robot and Empire series, indicating that they also were set in the same fictional universe.
Zaphod Beeblebrox is a fictional character in the various versions of the comic science fiction series The Hitchhiker's Guide to the Galaxy by Douglas Adams.
Tricia Marie McMillan, also known as Trillian Astra, is a fictional character from Douglas Adams' series The Hitchhiker's Guide to the Galaxy. She is most commonly referred to simply as "Trillian", a modification of her birth name, which she adopted because it sounded more "space-like". According to the movie version, her middle name is Marie. Physically, she is described as "a slim, darkish humanoid, with long waves of black hair, a full mouth, an odd little knob of a nose and ridiculously brown eyes," looking "vaguely Arabic."
A parallel universe, also known as a parallel dimension, alternate universe, or alternate reality, is a hypothetical self-contained plane of existence, co-existing with one's own. The sum of all potential parallel universes that constitute reality is often called a "multiverse".
Lester Neil Smith III, better known as L. Neil Smith, was an American libertarian science fiction author and political activist. His works include the trilogy of Lando Calrissian novels, all published in 1983: Lando Calrissian and the Mindharp of Sharu, Lando Calrissian and the Flamewind of Oseon, and Lando Calrissian and the Starcave of ThonBoka. He also wrote the novels Pallas, The Forge of the Elders, and The Probability Broach, each of which won the Libertarian Futurist Society's annual Prometheus Award for best libertarian science fiction novel. In 2016, Smith received a Special Award for Lifetime Achievement from the Libertarian Futurist Society.
Orion's Arm is a multi-authored online science fiction world-building project, first established in 2000 by M. Alan Kazlev, Donna Malcolm Hirsekorn, Bernd Helfert and Anders Sandberg and further co-authored by many people since. Anyone can contribute articles, stories, artwork, or music to the website. A large mailing list exists, in which members debate aspects of the world they are creating, discussing additions, modifications, issues arising, and work to be done.
Revan is a fictional character in the Star Wars franchise, created for BioWare's 2003 role-playing video game Star Wars: Knights of the Old Republic. Players may choose Revan's gender, appearance, and what path he follows throughout the game, but canonically the character is male and follows the light side of the Force. Within the game's narrative, Revan is a former Jedi hero who lived during the Old Republic Era. After turning to the dark side and becoming a Sith Lord, he took on the name Darth Revan and formed a Sith Empire to conquer the galaxy, contending with the Republic's armies. During a battle, Revan was betrayed and left for dead by his friend and Sith Apprentice, Darth Malak, who sought to usurp him. Subsequently, captured by the Jedi, Revan had his memory erased and was given a false identity, as part of the Jedi's plan to have Revan rejoin their ranks and help defeat Malak and his Empire. Revan's true identity isn't revealed to the player until later in the game, prior to which their custom character lacks any predefined identity and "Darth Revan" is believed to be dead.
Summertide (1990) is a science fiction novel by American writer Charles Sheffield, the first of his series of Heritage Universe. The story takes place millennia in the future, with humans having extensively colonized our spiral arm of the Milky Way and having encountered a number of intelligent alien races. Littered throughout the galaxy are hundreds of massive abandoned engineering projects built by a mysterious race, referred to as The Builders, extinct for three million years. An eclectic group of scientists and opportunists are descending upon one such artifact at a time when its surrounding environment is extremely dangerous to study an unusual phenomenon.
The Saga of Seven Suns is a series of seven space opera novels by American writer Kevin J. Anderson, published between 2002 and 2008. The books are set in a not-too-distant future where humans have colonized a number of other planets across the galaxy, thanks in part to technological assistance from an ancient alien race, the Ildirans. The series chronicles the universe-spanning war that erupts when humans inadvertently ignite the fury of a hidden empire of elemental aliens known as the hydrogues. Internal conflict is sparked within both the human and Ildiran empires as other ancient elemental races reappear to renew their own ancient war with the hydrogues.
Star-Lord is a fictional character and superhero appearing in American comic books published by Marvel Comics. The character, created by Steve Englehart and Steve Gan, first appeared in Marvel Preview #4. The son of human Meredith Quill and Spartoi J'son, Peter Quill assumes the mantle of Star-Lord, an interplanetary policeman.
Transcendence (1992) is a science fiction novel by American writer Charles Sheffield, part of his Heritage Universe series. This book is the sequel to Summertide and Divergence.
Convergence (1997) is a science fiction novel in the Heritage Universe series by American writer Charles Sheffield. This book is a sequel to Transcendence.
Resurgence (2002) is a science fiction novel by American writer Charles Sheffield, the finale of the Heritage Universe and the last book he published. Following the previous book in the series, Convergence, there are no more Builder artifacts left in the part of the galaxy explored by the four clades of the Orion Arm. However, an envoy from the neighboring Sagittarius Arm shows a short route to that arm and the ship's dead passengers carry an ominous message: a force even stronger than the Builders is consuming whole star systems in the neighboring arm.
The Beast Master is a science fiction novel by American writer Andre Norton, published by Harcourt in 1959. It inaugurated the Beast Master series, or Hosteen Storm series after the main character. In German-language translation it was published as Der Letzte der Navajos —literally, The Last of the Navajo.
Star Wars has been expanded to media other than the original films. This spin-off material is licensed and moderated by Lucasfilm, though during his involvement with the franchise Star Wars creator George Lucas reserved the right to both draw from and contradict it in his own works. Such derivative works have been produced concurrently with, between, and after the original, prequel, and sequel trilogies, as well as the spin-off films and television series. Commonly explored media include books, comic books, and video games, though other forms such as audio dramas have also been produced.
Gateway II: Homeworld is a 1993 interactive fiction video game developed and published by Legend Entertainment. The sequel to Gateway (1992), it is set in Frederik Pohl's Heechee universe.
The Forerunner Saga is a trilogy of science fiction novels by Greg Bear, based on the Halo series of video games. The books in the series are Halo: Cryptum (2011), Primordium (2012), and Silentium (2013). The books were released in hardcover, e-book, paperback, and audiobook. Bear was given little restriction on the story of the novel; the Halo universe had not yet been explored in that time period.
