Restricted Expanded Universe

Popular series often get adapted into other media than the original -- novels or comic books, for instance, made of movies or TV shows. But there's no way Luke Skywalker's going to get killed off in the Star Wars comic ; generally, licensed alternative media can't kill characters, develop relationships, alter the world, or make any sort of changes that have a chance of messing up the continuity for the original version.

These alternate media therefore can end up running in place and being inferior to the original because of the lack of change. Sometimes new characters to which change can happen are introduced to make up for the problem.

May be avoided if the original series is over. The newer Buffy the Vampire Slayer comics not only can change the status quo but are written by the series creator. The Doctor Who novels after the cancellation of the original series made changes and revealed great swaths of history, much of which had to be ignored when the TV series started up again over a decade later. One of the post-revival episodes is an explicit retelling of the novel Human Nature (by the same guy). Now that the Star Wars films are over, other media in that universe are also exempt.

This trope only applies if the adaptation is meant to follow the same continuity as the original series (though not necessarily vice versa). As a result it seldom applies in the opposite direction -- a movie made from a comic book can change anything the writer wants.

See also Status Quo Is God and Doomed By Canon.

Anime and Manga

 * The Tenchi Muyo manga had a big problem with this, since it was a case of Anime First and there were long stretches of time with no new Tenchi anime being published.
 * A variation of this happens in anime with Filler. The non-filler episodes are adapted from the manga and can advance the plot; the filler episodes cannot. Or, if they do, everything has to go back to the way it was before at the end of the filler.
 * Naruto
 * Bleach
 * Dragonball Z (The "Journey To Namek", "Return of Garlic Jr." and "Otherworld Tournament" arcs, respectively)
 * The Mobile Suit Gundam multiverse suffers this in spades. Since the events of the anime are set in stone (and have been that way for up to thirty years), manga and video game expansions almost always deal with an entirely new cast of characters, set off to the side of the anime's events and never directly interfering (though, on some rare occasions, having a degree of crossover).
 * A slight exception is the popular Gundam Seed spinoff Gundam Seed Astray, which was intended from the beginning to tie into the anime, occasionally patching up plot holes, and just barely missed being included in the anime itself.
 * However, the ongoing manga series Gundam the Origin completely and utterly ignores this (it helps that it's being written and illustrated by the original character designer and apparently has Tomino's blessing) and introduces a chain of events that while similar, are significantly changed and make a whole hell of a lot more sense in some respects. It's from here that a lot of the backstory for the mainline universe can be gleaned (though distortedly).
 * Even before Gundam the Origin, Tomino's adaptation of Mobile Suit Gundam completely subverts this trope by actually

Comic Books

 * The Star Trek comics did this. At one point even new characters couldn't be used because of fears that they would become Canon Immigrants that required royalties.
 * And the Star Wars comics: Knights of the Old Republic takes place 4,000 years before the movies, and Legacy 140 years after them. The KotOR comics are, of course, linked to the games by the same name that are set around the same time, and the comics are presumably limited by the games themselves more than anything else.
 * The Sonic X comics weren't allowed to introduce characters from the games that weren't introduced in the show, nor were they allowed to make any real changes to the status quo.

Literature

 * Writers for Star Wars Expanded Universe, besides following the regular continuity, have to abide to a certain set of rules established by Lucasfilm. Among those revealed to the fans are:
 * The Big Trio (Han, Luke and Leia) cannot be killed.
 * Members of certain alien species cannot become Jedi. Even though several Wookiee Jedi characters already exist, no new ones should be introduced.
 * Yoda's species and homeworld cannot be revealed.
 * Also a problem in the Star Trek novels, although the Star Trek New Frontier and I.K.S. Gorkon series dodge it by having new crews based off of one-shot characters, and the Titan series does by being set after the events of Star Trek Nemesis.
 * It seems that Paramount has given the writers more freedom in changing status quo in post-Nemesis stories, as in Before Dishonor.
 * And the in the Destiny trilogy. Isn't it fun to write in a universe where nothing canonical is coming out for years to come?
 * Trek novels have gone back and forth between Restricted and non-Restricted a couple of times. The novels of the '70s and early '80s tended to give authors a lot of freedom to interpret Star Trek in their own idiosyncratic ways, though the books rarely referenced or built on one another. By the later '80s, Pocket Books' Trek authors began referencing popular novels like Diane Duane's Romulan/Rihannsu books and John M Ford's Klingon epic The Final Reflection, and authors who did multiple novels increasingly carried continuity arcs forward within them, so an overall book continuity gradually began to emerge. But once Star Trek the Next Generation was on the air, Paramount began restricting the books and comics, forbidding them from referencing anything but the live-action canon, which killed continuity between books. Those rules began to relax in the late '90s, and by now, with all the shows off the air, the books have built up an elaborate, interconnected continuity. However, the new J. J. Abrams movie continuity operates under Restricted Expanded Universe rules -- so restricted, in fact, that only prequels to the movie have been allowed to be published so far.
 * The Mass Effect books have suffered greatly from this. Since a lot of choices are left to the player, the books have been forced to remain neutral on big issues such as as well as smaller ones right down to Commander Shepard's gender.

Live Action TV

 * This happened to Lost, in particular becoming a problem with the Expanded Universe video game -- nothing your character does can really affect the plot, so you end up doing various side things to advance your own story, while the show's plot happens offscreen.

Video Games

 * As in other things, Wing Commander gets into the act with this, too, in the form of novels built around canon characters from the game, particularly in the form of Jason "Bear" Bondarevski (first introduced in the Wing Commander 2 Expansion Pack Special Ops 1) in activities taking place in the Landreich. The Landreich, a vague analogy of the early United States (In Space), was pretty much created specifically for William Forstchen to have some place to play that won't break anything in the "core" universe of the games.

Western Animation

 * Star Wars the Clone Wars falls under this in regard to the movies. Since it takes place between Episodes II and III, you know Anakin, Obi-Wan, Yoda, General Grievous, Count Dooku, etc. are in no great peril. However, it doesn't seem to be restricted by the other existing canon.

Other

 * The Basalt City Chronicles, which is not only Restricted Expanded Universe (The author goes to the universe's creators for permission for virtually everything he adds), but is also that Verse's Manual.

Aversions/Subversions

 * Averted in the G.I. Joe comics, which could kill people and make changes, as long as the relevant action figure or other toy was no longer in production.
 * Likewise averted in the Transformers comics, which are almost universally all alternate continuities.
 * Vector Prime, the first novel of the Star Wars: The New Jedi Order series, was especially notable for having killed off . According to the author, the higher-ups had wanted to kill off a major Canon character in order to set up an Anyone Can Die atmosphere; the call eventually came down that was to be the Sacrificial Lamb based on.
 * The original plan was to kill off . Understandably, Lucasfilm objected.
 * Alice Randall wrote The Wind Done Gone as an explicit refutation of the limitations imposed by Margaret Mitchell's estate on those wishing to write sequels to Gone with the Wind.
 * A case of Canon Dis Continuity and Expanded Universe restrictions occurs in Greg Weisman's new Gargoyles comic. Continuing the beloved series after the end of Season 2, it refutes everything that happened in the Disney-produced Goliath Chronicles spin-off, (sans the first episode and one additional scene) essentially restricting the expanded canon to that comic alone.
 * The Matrix Online MMORPG features in its first chapter  eventually committing terrorist acts against the Machines, demanding that they return Neo's body, going so far as to create "code bombs" which reveal the Matrix code even to people still jacked in and not ready for such a revelation. The aversion comes when he is Killed Off for Real by a program known as the Assassin.
 * The Perfect Dark series leave a large gap in between the original and the prequel game, leaving the Greg Rucka novels (and comics) to expand and improve the characters and conspiracies of the universe. it also changed the backstories of  by placing them into a relationship
 * The Halo video games are rather light on plot, allowing the Expanded Universe to go hog-wild on it. The novels and comic books give characters new backstories and personality traits that were never hinted at in the games, fleshes out the origins of both the UNSC and the Covenant fully, adds in new weapons and vehicles, introduces and kills off many many characters on its own, and generally is.....better, at least as far as plot goes. The Expanded Universe is referenced multiple times in the later games.