- In some fandoms it's pretty much a given that the worst of fan material has irreversibly damaged the reputation and integrity of a canon.
- —Aster, PPC Boarder
Canon damage is present when there are permanent changes in canon, usually created by repeated badfic assault. Within the continuum, canon damage can include anything from subtle changes in the physical appearance of its residents to total disintegration of plot and setting. Outside the continuum itself, canon damage often expresses itself in the fact that World One residents, including most fan authors, tend to assume that the damaged version of the canon is actually the correct, original version. A continuum with severe canon damage will have a great deal of fanon that cannot be recognized as related to canon and may even directly contradict it.
Minor canon damage can be repaired, but the scars on the continuum tend to be permanent. Major canon damage is usually irreparable.
A continuum becomes vulnerable to canon damage when:
- The continuum becomes very popular, triggering a fanfic explosion and overloading the PPC's resources.
- It has a weak canon to begin with, especially if it contains canon Sues and pre-existing plotholes.
- The canon hosts a particularly horrible Legendary Badfic or a large number of bleepfics, especially for a long period of time.
- The canon is adapted into a new medium, such as a movie, game, comic, or book series, or receives an expanded universe in the form of a multimedia franchise. Some of this damage is minor; movie releases affix visions of what characters look like in the public's mind. Other damage is integral, often when an adaption is particularly unfaithful or poorly executed. Luckily, some creators shield their work from a bad adaptation or disown an extant bad adaptation, such as in the case of ATLA's movie adaptation, The Last Airbender. Other franchises are not so lucky.
Continua with permanent canon damage include:
- Almost every continuum that has ever hosted a fanfic explosion. In very strong continua, the canon damage tends to be limited to minor changes. An example of minor canon damage is the misquote, "Alas, poor Yorick; I knew him well," from Hamlet, which the continuum is continually trying to repair.
- Twilight. The combination of fanfic explosion and canon Sues creates a continuum that is unable to defend itself adequately against badfic, and is an unusually hostile continuum for PPC agents brave (or crazy) enough to venture into it.
- Uncle Tom's Cabin, which sustained major damage due to fan-made performances conducted with little regard for canon. The worst damage came from those who did not like the message Stowe wanted to get across and rewrote the story to suit their own opinions.
- The Sonic Universe, which has been damaged by modern canon installments, Legendary Badfic and bleepfic.
If canon damage is protracted and constant, a canon may suffer complete destruction, fading out of memory altogether as it collapses in on itself. For obvious reasons, no such continua are known, though it is known that at some point, they existed, and now they do not.