The main SCP object classes are Safe, Euclid, Keter, Thaumiel, Neutralized, and Explained. In newer SCP classification systems, you may also see broader labels like disruption, containment, and risk classes.

Main object classes

  • Safe : Anomalies that are easy to contain and usually predictable in how they behave.
  • Euclid : Anomalies that are harder to contain because their behavior is less predictable or not fully understood.
  • Keter : Anomalies that are very difficult or effectively impossible to contain reliably.
  • Thaumiel : Rare anomalies used by the Foundation to help contain other anomalies.
  • Neutralized : Anomalies that have been destroyed or made non-anomalous.
  • Explained : Anomalies whose effects are fully understood or no longer anomalous in practice.

Newer classification layers

The SCP wiki also uses the Anomaly Classification System (ACS) , which adds other ways to describe an SCP beyond the classic object class. That system includes things like disruption class and risk class , which focus on how much an anomaly affects normal society and how dangerous it is.

Simple way to think about it

A quick mental model is:

  1. Safe = easy to store.
  2. Euclid = hard to predict.
  3. Keter = very hard to hold.
  4. Thaumiel = useful to the Foundation.
  5. Neutralized = no longer active.
  6. Explained = understood enough that the mystery is gone.

Note

Different SCP articles can use slightly different classification styles, so not every entry follows the same exact format.