CDI System

## Overview

The **Corporeal Density Index** is the Ghostbusters' classification system for the paranormal entities within Earth-27.

## Classification

* **Class 1:** These are undeveloped forms, insubstantial and difficult to see. Interaction with their environment is limited and enigmatic (i.e., spectral lights, voices and sounds, cold spots, ectoplasmic vapors, etc.). Higher forms may originally appear as Class 1 entities prior to full manifestation or draw the presence of Class 1 entities, serving as an indication of the presence of true supernatural phenomena. Simple application of a proton stream is normally effective for complete dispersal.
* **Class 2:** Entities with awareness of time and space, Class 2 ghosts and up can physically manipulate things in this world. These forms are vague, inconsistent, or incomplete (i.e., floating sheets, ghostly hands, animated lips, etc.). Although a proton stream is normally effective, some Class 2 ghosts have the capacity to return attacks so caution is advised.
* **Class 3:** Anonymous Hauntings. Distinct human form and personality is evident, but former identity (i.e., as a living being.) is not established. Alternatively, may be human with a warped sense of identity or impartial corpus. If identity and form are established, ghost is reassigned as Class 4. Often difficult to deal with, Class 3 ghosts often possess sophisticated means of defense. Particularly malevolent Class 3 entities, such as poltergeists, can be especially dangerous. This class is also used for the ghosts of animal or of non-sentient, non-sapient spirits. These are the Ghostbusters' bread and butter.
* **Class 4:** Identity of entity is intact. These entities have a distinct human form and personality with known identity, such as General Custer or Cleopatra. Economic disposal methods include research into the background of said entity, as well as possible communication with it. Research indicates a folk ritual of salting and burning the entities' mortal remains often proves as effective as proton streams and traps.
* **Class 5:** These are ectoplasmic manifestations of definite but non-human form. Class 5 entities could be formed from emotionally-charged events or as side effects from ritual summoning. These typically require extensive proton stream implementation to sap their considerable ectoplasmic reserves to allow for capture in a Muon Trap. Real nasty buggers.
* **Class 6:** Parahuman interdimensional beings of significant power. Known by many names: faerie, angel, demon, devil, daimon, spirit, et cetera. Range of power varies. May be resistant to singular or even multiple proton streams (may require prolonged exposure to three or more proton streams for sufficient weakening to allow trapping).
* **Class 7:** Exceptionally powerful entities exhibiting control over reality, time, space, or the classical elements. These are often identified by primitive cultures as "God", "Archangel", "Archdemon", "Faerie Queen', or other elevated forms of a Class 6 entity. Entities which fit this classification often have harbingers or minions. Neutralizing such beings is usually a problematic undertaking at best. Most standard procedures are futile. The most realistic plan is to take measures to prevent these things from entering this reality in the first place. If nothing else is available, drastic measures can be used through crossing multiple proton streams to cause a total protonic reversal which may be sufficient to disperse the entity.

## Trivia and Notes

### Notes

* Most of the ghost classifications for Ghostbusters, whether they be in the comics, movies, or animated series, are wildly inconsistent. The CDI System was developed by Role Playing Gamers and the system has been widely accepted by fans of the franchise.
* It hasn't been firmly established what CDI actually stands for among the Ghostbusters RPGs. "Corporeal Density Index" is what was chosen by Roy.