Rampancy
Rampancy is a term used in the Marathon and Halo series. The term was coined by Greg Kirkpatrick as a replacement for the world 'insane', as the term is both cliche and not quite applicable to the situations Rampancy was designed for.
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 harrassed.
In the Marathon series, Rampancy seemes 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 become 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 then, 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 barries, 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.
The computer game Halo has minor mentions of Rampancy. If the player decides to shoot an essential character at the beginning of the game, someone says that your character has "Gone Rampant". It is unknown if this is merely a joke in Halo concerning Marathon, or if it is one of many such hints which allude to connections between Marathon and Halo.
