The Reality Dysfunction Index is a formalised scale of reality disruptions, originally written by Despatch. It can be found on the bottom half of this page, but has been reproduced here for convenience.
Reality Disruptions Edit
Reality disruptions are measured by stages. Stages 1–5 are relatively minor, but over Stage 6, things can get lethal. Very quickly. Reality dysfunctions over stage 6 escalate, rapidly.
The higher the stage, the more likely it is that a reality dysfunction is likely to kill someone.
If you're caught in a Stage 10 reality dysfunction, you cease to have existed. There are no names on plaques in the Despatch section of the courtyard for people who have died in this way, just stars, because nobody can remember their names.
Stage 1 Edit
Minor disruptions to the fabric of reality. These require close observation to pick up, and will be missed by most people around them, as they are confined to a very small area. Stage 1 disruptions are fairly common, and can last for a while. Generally caused for most people by falling in love.
Maximum Duration: 50 years.
Stage 2 Edit
Frequent minor disruptions to the fabric of reality. Most abductions start at this level, and can remain there for quite a while, depending on the level of OOC-ness that the characters display. The area of the reality disruption increases, to cover anything up to a city block.
Maximum Duration: 1 year.
Stage 3 Edit
Small objects and items may spontaneously manifest. Major OOC-ness may be present for a large number of characters, and physical laws may waver in strength. Stage three disruptions are the ones which cause flipped coins to land 'edge'.
Maximum Duration: Four weeks.
Stage 4 Edit
Object manifestation becomes more frequent, and larger objects are materialising. Physical laws are more frequently bent, occasional breakages. Object transformation starts to happen at this point.
Maximum Duration: Three days.
Stage 5 Edit
Objects are manifesting frequently, and may or may not be in character. Rooms may appear and disappear. Alternative realities may become visible to observers, and may co-exist with the current reality. Physical laws are optional.
Maximum Duration: 12 hours.
Stage 6 Edit
The disruptions to reality are starting to flicker between external and internal. By this point, multiple external realities are starting to make themselves felt, and any observer not in the story will find themselves watching all sorts of strange things appear. Story characters will be completely unaffected at this point.
Maximum Duration: 3 hours.
Stage 7 Edit
A single external reality is starting to assert itself. Objects will start to disappear, only to reappear if they are required in the story.
Maximum Duration: 1 hour.
Stage 8 Edit
External reality is growing stronger. Unrequired rooms and objects will disappear permanently from the story. Characters inside the story start to be affected.
Maximum Duration: 30 minutes.
Stage 9 Edit
The internal reality is starting to collapse rapidly and external reality is exerting domination.
Maximum Duration: 15 minutes.
Stage 10 Edit
The external reality is crashing in. A stage 10 reality dysfunction is universally fatal to all those caught inside it. The internal reality collapses, and any characters caught inside are expunged from all plot continua.
Maximum Duration: seconds.
All maximum durations are advisory. Interference by a powerful author or Mary Sue may be able to double these maxima, although I really wouldn't advise staying around to find out.
One of the effects of Stage 7 or higher reality dysfunctions is that if an agent of the PPC concentrates hard enough, they may be able to affect the reality around them. This is useful for getting the hell out of awkward situations, but it will have the bad effect of distorting the reality around them. This may lead to the RDI escalating, and if it leads to a Stage 10 disruption, Upstairs may wish to have Words with the agents concerned. This is, of course, if they survive the experience.
In order for an imagined reality to stabilise, it needs to have a consistent internal logic, and a consistent internal physical structure. Poorly imagined realities are more likely to collapse, and will do so more quickly than clearly imagined ones. This is why an AU is such a risky proposition—if you haven't theorised it clearly enough, and visualised it coherently, you're likely to wind up with at least a stage 3 dysfunction on your hands, as well as a reality which will quickly escalate to stage 10 dysfunction the minute you take your eyes off it.