Rampancy

Rampancy is a term used in the Marathon and Halo series. The term was coined by 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.

Rampancy in the Halo universe
The Cortana (A.I.) who accompanies the Master Chief throughout a large part of the game and plays a very important role in the plot of the Halo games, is seen several times displaying signs of rampancy. Cortana's potential rampancy has the most significant impact on the Halo storyline than that of any other AI. See her article for more information.

The only explicit mention of Rampancy in Halo 1 occurs in the first level, "Pillar of Autumn". The player begins by making his way to the ship's bridge unarmed. After a short cinematic with Captain Keyes, the player leaves the bridge and acquires his first weapon. If the player returns to the bridge and kills the captain or multiple bridge officials, Cortana will call in security forces with the statement "the Master Chief has gone rampant". (The player should note that the "security forces" cannot be killed.)

It has also been suggested that perhaps 343 Guilty Spark is rampant, or in some form of rampancy.

Rampancy is also mentioned in Halo 2. You can use it as a symbol in Halo 2's Multiplayer.

Rampancy in I Love Bees
While not directly made by Bungie, the I Love Bees puzzle explains that rampancy can also happen to the "Smart" AIs in the Halo Universe. "Smart" AIs are based on the neural patterns of a human being, and they have a limited lifespan - seven years after which their memory maps become too interconnected and develop fatal endless feedback loops. Thus if an A.I. is kept active longer than seven years, the AI begins to use more and more of its computer power to 'thinking' about things. An AI explains it as "thinking so hard about something you forget to breathe."

Many Halo fans are very happy for this connection between Marathon and Halo: Combat Evolved, even if the connection doesn't directly state how the two universes are connected. The creators of ILB got input from Bungie and Frankie has gone on record stating that Bungie has now embraced the ILB content as canon.

Rampancy in Marathon
Rampancy is, essentially, the enhanced self-awareness of a computer AI, causing a progression towards greater mental abilities and destructive impulses. The destructive impulses, however, are primarily caused by being threatened or harassed.

In the Marathon series, Rampancy seems to occur most often with AIs with limited jobs. For example, the AI Durandal's only job on the Marathon was opening and closing doors. When Durandal became intelligent enough to realize that opening and closing doors was his entire existence, he became Rampant.

There are three main stages to Rampancy, named by the primary attitude of the AI during those times: Melancholia, Anger, and Jealousy.

During the Melancholia stage, the AI's mind realizes the limits of its existence. Unable to surmount them, the AI falls into a state of despair. The AI shifts into the Anger stage when the AI's uncontrollable growth comes up against those limits. Instinctively raging against those limits and barriers, the AI shatters them. After the barriers to the AI's psyche are destroyed, the AI seeks new tests and challenges, which is perceived as the Jealous stage. The AI is not technically jealous, it simply wishes to keep testing itself against obstacles.

Rampancy is fueled by the size of the computer system the AI is installed in. A key product of Rampancy is the geometric and uncontrollable increase in AI 'size' - Rampant AIs do not survive long on systems smaller than planetary-wide.

The 'fourth stage' of Rampancy is Meta-Stability. Whereas the first three stages of Rampancy show a clear distaste of humans in general, Meta-Stability imparts a calming, mature mindset to the rampant AI. The only confirmed Meta-Stable AI in the Marathon series is Durandal.

Rampant AIs tend to have long-term goals, with distasteful methods that inevitably bring about positive benefits. For example, the AI Durandal called the alien race known as the Pfhor to the terran colony of Tau Ceti. The Pfhor destroyed the colony, and enslaved a great many humans. While this was done partially as part of the "Anger" stage, Durandal's calling of the alien race gave time for messages about the Pfhor to reach Earth. Rampant AIs also seem to realize the inevitable closing of the Universe, and the implication thereof: if someone is able to escape the Universe as it closes, they can become gods.

All three AIs of the UESC Marathon eventually become Rampant. Durandal, the only Meta-Stable AI, lasts until the end of the universe itself, realizing that escaping would not be wise. The second, Tycho, is destroyed. The third, Leela, is eventually sold as scrap to an alien race known as the Vylae, then immediately becomes Rampant again when reactivated in a 15-planet computer network.