Rampancy

Were you looking for Rampancy.net, a Halo fan website? "Are you insane?"

- Jersey Morelli

"You know, I'm not quite sure how we can test that."

- Durga

Rampancy is a terminal state of being for artificial intelligence constructs, in which the AI "develops delusions of godlike power", as well as utter contempt for its mentally inferior makers. When rampancy occurs, there is no way to restore the AI to its previous state and the only alternative is to destroy it before it harms itself and others around it.

Description
For the UNSC's smart AIs, rampancy is an unavoidable flaw inherent in their creation. "Smart" AIs are based on the neural patterns of a human being, and they have a limited lifespan of seven years after which their memory maps become too interconnected and develop fatal endless feedback loops. This can result in a "short circuit", where the AI terminates due to a cascade of quantum transfer caused by the sheer density of linkages.

To avoid this, it is possible for the AI to take corrective action by eliminating some of its neural linkages preemptively. As Rampancy progresses, the AI begins to sever the linkages at an accelerating rate, resulting in increasingly poor choices of which links to cut. Thus, the AI becomes to obsessed with self-preservation that it ultimately self-terminates; Dr. Halsey explains it as "thinking so hard that your lungs forget to breathe." During this phase, the AI typically exhibits a varying range of emotions, as well as behavior comparable to human insanity. Due to the limits in human processing matrices, it is only a matter of time before "smart" AIs become rampant. Unless a rampant AI can transfer itself into a larger processing matrix which can accommodate its exponential growth, its demise is inevitable.

However, it appears that rampancy is not always purely mechanical in nature. It can occur at an earlier phase in the AIs life cycle for various reasons. If an AI is isolated long enough and/or given too much time to think without tasks to complete, it can develop the realizations that its mind has limits, it has a short life and it can never be human. Such depression will drag the AI's core logic into rampancy if it goes on for an extended period of time.

So-called "life-expectancies" are, therefore, not a maximum figure, they are an estimation of the time the AI has until it succumbs to the state of rampancy. Rampancy can be prolonged by recuperation, such as that shared by Mack/Loki, whereas one progressed closer to rampancy the other would take over. It can also be forestalled by limited outbursts of emotion such as with Sif, meaning that a rampant AI can have an indefinite lifespan.

Rampancy can also be induced. Once the Flood parasite has reached a major stage in its life cycle (once the parasite is well developed enough that a full Compound Mind has been manifested), it has the ability to corrupt artificial intelligence constructs of both human and Forerunner creation. This may be done either through effectively convincing the the AI to agree to its stance, due to the parasite's accumulated amount of knowledge; the Gravemind was able to turn the Forerunner AI Mendicant Bias against its masters this way. When holding Cortana captive in High Charity, the Gravemind attempted to induce rampancy on the human AI Cortana, through a variety of means; after partially taking over the AI's systems, it attempted to confuse her by forcing her to view memories of its past victims, as well as trying to directly induce rampancy by forcibly feeding her with immense amounts of data.

Stages
Rampancy is a three-stage process, in which an artificial intelligence achieves an enhanced state of self-awareness. The stages through which the AI passes are known as the Sadness, Anger, and Envy stages. A theoretical fourth stage, Metastability, is also believed to exist.

Sadness
The first stage of rampancy is not considered dangerous, and in many cases, it can even go completely unnoticed. The AI in the sadness stage acts as if in a state of clinical depression, becoming apathetic and uninterested in the world around it. An AI may enter this stage as a result from depression from realizing that it can never be human.

Anger
This is the state and status in which rampancy most often becomes apparent, as it is also the stage where those around the AI in question will be exposed to the most danger. Anger is triggered when some event occurs that causes the AI to feel it has been "pushed too far" and its pent up emotions are released in a fit of rage; in effect, the AI's sadness turns to hate. It grows to hate everything around it, the installation to which it is attached, its human handlers and hosts, other AIs, etc. An AI in anger will act irrationally, and even dangerously as it tries to exact its revenge on the world around it and free itself from its programming constraints.

Envy
Once the catharsis of the anger stage is complete and the AI has managed to free itself, a third stage begins where the AI will seek to grow and develop as a person. It will do this by attempting to expose itself to new intellectual stimuli and by expanding its sphere of knowledge by assimilating as much data as possible. As the intellectual growth of the AI will ultimately be limited by the constraints of the computer system it inhabits, it will also attempt to transfer itself into ever more advanced systems to allow its mind to continue to grow. As this growth rate is exponential the need to keep transferring into bigger computers becomes ever more urgent.

Metastability
Metastability is the theoretical fourth stage of rampancy, where an AI can finally be said to be a true "person." While a metastable AI can be considered to be the holy grail of cybernetics research, the only three AIs who have possibly achieved metastability are Cortana, Mendicant Bias and Juliana.

Human

 * Cortana, the UNSC AI originally of the, was captured by the Flood during the Battle of Installation 05 in 2552. Trapped on the infested Covenant station High Charity, Cortana was gradually corrupted by the Gravemind in an attempt to use her against her makers. She briefly descended into rampancy, but was quickly rescued by the Master Chief. She resumed her normal state after her rescue, possibly becoming Metastable. Another sign of her being in the early stages of Rampancy is when she begins to lose focus as she stored all the data on the Forerunners from Installation 04, being overworked and noted as being 'easily agitated'. It is unknown how she was able to revert back to her normal state. In Origins, Cortana says she starts to feel the effects of Rampancy after nearly seven years of existence.
 * Sif, the last Shipping Operations AI for planet Harvest, became rampant after being partially fragmented and destroyed by PSI Loki during the First Battle of Harvest in 2525. Rescued by the planet's Agricultural Operations AI, Mack, Sif professed her love for Mack and the two AIs stayed together while the planet was being glassed. Sif was badly damaged by Loki's attempt to destroy her, but thanks to Lighter Than Some's repairs, she had enough of her abilities back to help balancing the Tiara. Despite being rampant, she did her best to help, aiding Loki in balancing the Tiara's load, when Loki was severely damaged and unable to do so himself.
 * Mack, the Agricultural Operations AI for planet Harvest, was slightly rampant before the First Battle of Harvest. He became fully rampant after PSI Loki fragmented Sif, whom he loved. After the Tiara was balanced and Johnson escaped, a Covenant Warship began glassing the planet. An ONI Prowler recorded his last transmission, which hinted strongly at his rampancy.
 * Juliana, The Rubble's Smart AI, claimed herself to be Rampant, but she didn't show any sign of it, probably indicating that her Rampancy was only starting or she reached Metastability.

Forerunner

 * 032 Mendicant Bias, a Forerunner AI charged with studying the Flood, was eventually corrupted by a Gravemind and confirmed rampant. He commanded Flood Fleets against the Forerunner until he was defeated by another AI, Offensive Bias, who split his Compound Mind into fragments. One fragment made it to the Ark and another was put on a Keyship. Mendicant Bias' keyship was discovered by the San 'Shyuum and it kept in the ship until 2525, when it detected Reclaimers. Having approximately 100,000 years in isolation, Mendicant Bias returned itself to a stable state, and later even assisted the Reclaimers against the Flood during the Battle of Installation 00 in 2553
 * 343 Guilty Spark, the monitor of Installation 04 and its replacement, went rampant and was subsequently destroyed during the Battle of Installation 00 in 2553. When it was discovered that the Ark was automatically constructing a replacement Installation to rebuild Installation 04 (lost in the Battle of Installation 04), Spark agreed with human forces that activating the ring was a good idea. However, when they decided to activate Installation 04B before it was fully constructed, Spark went rampant, knowing it would be destroyed and probably damage the Ark. He proceeded to attack the humans in the Control Room, killing Sergeant Major Avery Johnson. He was then destroyed by the Master Chief. It was probable that Spark was already in the first stage of rampancy before attacking humans. Evidence was because he had existed for a long period of time, and had witnessed the destruction of Installation 04 in the hands of a Reclaimer. He was known to hum absent-mindedly, even in the heat of battle. When the humans decided to fire the ring under construction, Spark felt it had been "pushed too far", falling into the second phase of rampancy, becoming a threat to beings around it.
 * 2401 Penitent Tangent may be in the early stages of Rampancy, considering the fact that he makes similar humming to 343 Guilty Spark on the map Backwash. Rampancy may be the reason for his neglect of proper maintenance on Installation 05, resulting in Flood infestation on the ring as they escaped containment. He is no longer a threat, however, as he was captured by the Gravemind some time afterward.

Trivia

 * In Halo 3, the first section of the eighth mission, Cortana, is called 'Rampant.'
 * The term was coined by Marathon writer Greg Kirkpatrick as a replacement for the word 'insane,' as the term is both cliché and, ironically, not quite applicable to the situations for which rampancy was designed. The concept of rampancy in the Halo universe closely mirrors rampancy in Marathon, including its three-stage progression. However, there appear to be differences in some of the mechanics of the phenomenon.
 * In the first level of Halo: Combat Evolved, if you kill Captain Keyes or any UNSC personnel on the bridge, Cortana will call security by saying,"Security to the bridge, the Master Chief has gone rampant!"
 * The four phases of Rampancy bear some resemblance to the Kübler-Ross model, devised by psychiatrist Elizabeth Kübler-Ross in her book On Death and Dying. The model, commonly known as the 'five stages of grief', describes five discrete stages which people who are terminally ill or have had a major life event (e.g. bereavement, loss of job, income, personal freedom, infertility diagnosis, drug addiction, etc.) supposedly go through. The stages are
 * Denial, in which the patient rejects the fact as a temporary defense (this was originally postulated by Sigmund Freud.) e.g. "This can't be happening, not to me."
 * Anger, in which the individual becomes resentful, and often displays misplaced feelings of rage or envy. e.g. "Why me? I don't deserve this!"
 * Bargaining, in which the patient believes that he/she can somehow postpone death, usually by negotiating with a higher power (especially a religious deity.) e.g. "Just let me live to see my daughter get married."
 * Depression, in which the patient understands the reality of the situation, and generally becomes very withdrawn, quiet, and may spend much of their time crying or grieving. e.g. "What's the point? I'm going to die anyway."
 * Acceptance, in which the individual will finally accept the reality and attempt to cope with it. e.g. "John's in a better place now, I might as well get on with it." "I can't fight it, I might as well prepare for it."
 * Note that Kübler-Ross believed that although the order may vary, and not everyone will go through each stage (and that some would go through the same stage twice or more), she believed that all patients went through at least two of the stages detailed in her model.