Understanding SCP object classes is essential for navigating the collaborative science fiction and horror writing of the SCP Foundation Wiki. Many readers and beginner writers confuse these designations with a threat level, assuming that a higher class means a more destructive entity. In reality, object classes measure how difficult an anomaly is to contain and how much resource allocation it demands.
An object class does not tell you if an entity is hostile. For instance, a box that triggers an apocalypse if opened can be completely Safe if it stays shut, while a harmless, teleporting feline might be classified as Keter because keeping track of it is a logistical nightmare. Let's break down how the system works, what the primary and secondary tiers mean, and how authors use the "Locked Box Test" to categorize anomalies.
The Core Principle: What Is the Locked Box Test?
Before looking at individual categories, it helps to understand the informal rule used by community writers to determine an anomaly's class. It's called the Locked Box Test:
- If you lock it in a box, leave it alone, and nothing bad happens, it's Safe.
- If you lock it in a box, leave it alone, and you never quite know what it's going to do, it's Euclid.
- If you lock it in a box, leave it alone, and it easily escapes or destroys the box, it's Keter.
- If the anomaly is the box, it's Thaumiel.
- If you can't put it in a box and humanity is facing imminent doom, it's Apollyon.
This heuristic strips away the horror elements and focuses purely on administrative and engineering realities. The Foundation is a bureaucratic organization at its core, managing risks with standard operating procedures. To read more about the history here, Associated Press offers an in-depth breakdown.
The Primary Object Classes
The vast majority of articles on the database rely on three main categories. These primary classes form the foundation of almost every early article and establish the baseline operational burden for containment sites.
Safe-Class Anomalies
Safe-class SCPs are anomalies that are thoroughly understood and reliably contained. This designation does not mean the item is friendly or risk-free. A nuclear warhead can be Safe if it sits in a concrete bunker without a trigger mechanism, just as a sentient blade that cuts through anything is Safe if it stays locked inside a reinforced vault.
The defining trait of Safe anomalies is that they don't trigger their anomalous properties unless someone intentionally activates them or interacts with them, and the Foundation possesses the resources and knowledge to suppress them permanently. Examples include SCP-999 (a gelatinous, tickling orange creature) and SCP-914 (a clockwork booth that refines items placed inside).
Euclid-Class Anomalies
Euclid is the most common and broad category in the database. Euclid-class items are either insufficiently understood or inherently unpredictable. Even if the Foundation builds a secure cell, containment isn't guaranteed to hold indefinitely because the object possesses autonomy, sapience, or erratic behavior.
As a rule of thumb, any anomaly that can think, act, or make independent decisions defaults to Euclid at minimum. Humanoids, sentient statues, and unpredictable biological entities fit here. For example, SCP-173 requires constant direct line-of-sight from multiple personnel to prevent hostile movement, making its containment a delicate, labor-intensive chore.
Keter-Class Anomalies
Keter-class anomalies are exceedingly difficult to contain consistently. Procedures for these objects are massive, complex, and prone to catastrophic failure. The Foundation often lacks the technology to completely neutralize or suppress a Keter anomaly, meaning staff spend their time managing containment breaches rather than achieving stable equilibrium.
A classic example is SCP-106, an entity that can corrode solid matter and walk through walls, requiring high-value human sacrifices and complex electromagnetic holding cells to redirect its path. Keter objects represent systemic threats that keep Site Directors awake at night.
Secondary and Esoteric Object Classes
As the collaborative writing project evolved, authors introduced secondary and esoteric classes to handle unusual narrative structures. These tags provide flavor and nuance beyond standard containment boxes.
Thaumiel-Class SCPs
Thaumiel-class objects are top-secret anomalies utilized by the Foundation to contain other, more dangerous threats. Their existence is heavily restricted, often known only to high-ranking administrative bodies like the O5 Council. Instead of being locked away to protect the world, they serve as active tools—such as reality-anchoring networks or spatial anomalies used to suppress Keter-class breaches.
Apollyon-Class SCPs
Apollyon designates an uncontainable anomaly that threatens an active, irreversible end-of-the-world scenario. When an object is labeled Apollyon, containment has effectively failed or is impossible. The Foundation is no longer managing a secure site; they are desperately searching for a miracle to delay total annihilation.
Archon-Class SCPs
Archon-class objects are anomalies that could theoretically be put into a containment cell, but the Foundation actively chooses to leave them uncontained. Moving or sealing an Archon object would cause more harm than letting it exist naturally in public view, often because it forms an invisible part of consensus reality.
Neutralized and Explained Classes
- Neutralized (-NE): Anomalies that have been intentionally or accidentally destroyed, disabled, or stripped of their anomalous traits.
- Explained (-EX): Phenomena that were once thought to be anomalous but are now fully understood through mainstream science or exposed as elaborate hoaxes.
Common Mistakes Writers Make With Object Classes
When drafting original fiction for the SCP Wiki guidelines, creators often stumble over how these categories function. Avoiding these pitfalls will make your drafts feel authentic to the setting.
One frequent error is treating object classes as power scaling tiers. Authors sometimes upgrade an anomaly to Keter simply because it destroys planets, ignoring whether it sits quietly in a lead box. If a universe-destroying button requires zero effort to keep dormant, it's Safe.
Another mistake is overusing esoteric classes like Apollyon or Archon. These labels carry heavy narrative weight and lose their impact if assigned casually. Stick to the primary triad of Safe, Euclid, and Keter unless your story demands a specialized operational framework.
Frequently Asked Questions
Can an SCP change its object class over time?
Yes. If researchers gain a better understanding of an unpredictable entity or upgrade containment engineering, a Keter object might be reclassified as Euclid. Conversely, a containment failure or sudden mutation can force an upgrade.
Are all anomalous humans classified as Euclid?
Most sapient humanoids default to Euclid due to their free will and unpredictable behavior. However, a cooperative human with no powers who merely possesses anomalous knowledge might be classified as Safe if they reside willingly in a standard containment suite.
What does a Neutralized classification mean for the story?
A Neutralized tag indicates that the anomaly is dead, broken, or mundane. Writers often use this designation to tell bittersweet or tragic stories about the permanence of loss and the fading of wondrous or terrifying things from the world.
Do object classes appear in the public-facing lore of the Foundation universe?
Within the fictional universe, the Foundation operates under absolute secrecy (the Veil). Object classes are strictly internal administrative tools used by researchers, guards, and site administrators to maintain operational security and manage budgets.
