The SCP Foundation categorizes its contained anomalies using a standardized set of classes that describe the general behavior and threat profile of an object, entity, or phenomenon. Understanding these classifications is essential for anyone interacting with the database, as they provide immediate context regarding how dangerous and unpredictable a specific SCP is. While the primary system uses Safe, Euclid, and Keter, the Foundation employs a broader spectrum of designations to address metaphysical, informational, and situational complexities that do not fit neatly into the initial three tiers.
Standard Behavioral Classes
The three standard classes form the backbone of SCP classification and are used for the majority of documented anomalies. These categories are based on the ease of containment and the level of risk the object poses to personnel and the global community. The definitions are fluid, however, and an SCP’s classification can be upgraded or downgraded based on new observations or successful containment procedures.
Safe Class
An SCP classified as Safe is fully contained and poses minimal risk to personnel under standard procedures. These anomalies are usually predictable, non-sentient, or easily neutralized, allowing for straightforward handling with minimal resources. Despite the low risk designation, Safe class objects are not harmless; they are simply the most manageable within the Foundation’s inventory, ranging from mundane artifacts to physically constrained entities that require constant observation but offer no active resistance.
Euclid Class
Euclid class SCPs represent the bulk of anomalies due to their unpredictable nature or difficulty in containment. These objects, entities, or locations may be sentient, require complex protocols, or exhibit reality-bending properties that make them unreliable and dangerous. Euclid classifications are often temporary, as researchers work to develop more reliable containment methods, but they remain the most common classification for entities that are sapient or exhibit complex, variable behaviors that cannot be fully anticipated.
Keter Class
Keter class SCPs are the most dangerous and difficult to contain, representing threats that could cause global catastrophe if released. These anomalies typically exhibit extreme resilience, intelligence, or reality-altering capabilities that render standard containment measures ineffective. Because of the high resource allocation required, Keter objects are often only managed rather than truly contained, with protocols focused on delay, distraction, or preventing public knowledge rather than outright neutralization.
Special and Esoteric Classes
Beyond the standard behavioral triad, the Foundation utilizes a range of special classes to address anomalies that operate on unconventional principles. These designations acknowledge that some threats are not defined by brute strength but by their ability to circumvent reality, information, or the very laws of physics. Assigning these classes helps personnel understand the specific nature of the hazard and tailor response protocols accordingly.
Thaumiel Class
Thaumiel class SCPs are the rarest and most strategically valuable anomalies, functioning as tools or countermeasures against other SCPs. These objects are actively utilized by the Foundation to contain or neutralize Keter-level threats, essentially serving as a weapon or safeguard against existential risks. Due to their critical nature, knowledge of Thaumiel-class objects is highly restricted, known only to O5 Command and a select few personnel to prevent exploitation or compromise.
Neutralized and Explained
The Neutralized designation is applied to SCPs that have been successfully destroyed, rendered inert, or whose anomalies have been completely nullified. This status indicates that the object no longer poses a threat, though the classification may remain for historical and procedural records. Explained anomalies are those that, through rigorous scientific study, have been determined to be non-anomalous; they were misidentified natural phenomena, hoaxes, or effects that can be replicated with mundane technology, leading to their removal from active containment.
