Rating

The rating of a ghoul is set through evaluation of the ghoul's individual ability. The following criteria are employed to determine the rating according to their individual ability:[2]
 * SSS rated
 * Criteria is unclear.


 * SS rated
 * Multiple Special Class Investigators are needed.


 * S+ rated
 * Equivalent to the ability of an average Special Class Investigator. (approx.)


 * S- rated
 * Equivalent to the ability of an average Associate Special Class Investigator. (approx.)


 * A rated
 * Comparable to a First Class Investigator.


 * B rated
 * Comparable to a Rank 1 to Rank 3 Investigator.


 * C rated
 * Ghouls of smaller ability.

In addition to the ghoul's individual ability, the actual damage caused by the ghoul is also evaluated. The rating is set in consideration of the predation and killing incidents committed by the ghoul.

For some ghouls, their influence over other ghouls is also taken into account when ratings are given. An example of this could be Big Madam.