Editing 2300 AD (section)

== Sentient species ==
{{in-universe|section|date=April 2024}}

The following sentient species are known to humans in ''2300 AD'':

* The awesome and enigmatic ''AGRA Intelligence''
* ''Ebers'': confined to one planet in 2300, they once had an interstellar civilization with a presence on at least three other planets, although all that is left of them on those planets are ruins from a destructive war.
* ''Kafers (Kaefers)'': the primary adversary species in ''2300 AD'' are humanoids with mandibles and integument similar to some Terran insects and a hard dorsal shell (thus the name derived from German ''Käfer'', "beetle"). Their technological advancement is equivalent to humanity's, including interstellar travel capability. Kafer individuals normally have a low intelligence, approximate to a human [[IQ]] of 40. However, in stressful situations, their equivalent to an [[adrenaline]] reaction functions as a neural accelerant, pleasurably increasing [[Situation awareness|situational awareness]], speed of reasoning, and creativity. The Kafers feel most alive when in danger, and are, in effect, addicted to it.  The more often an individual Kafer experiences stress-induced intelligence, the more intelligent they remain in a non-stressed state. While the Kafers are carrion-eating scavengers, and not intrinsically violent, their neurobiology creates a quandary for their civilization:  civilization acts to reduce violence and stress and leads to a steady loss of a Kafer culture's intelligence and, finally, inevitable conquest by smarter, less-civilized cultures.  The present Kafer civilization has resolved this quandary with systems of ritualized violence and a glorification of war. Ruled over by a [[Oligarchy|small minority]] of "permanently bright" individuals, the Kafers are paradoxically both terrified and excited by humanity, since humans resemble the "smart barbarians" that periodically destroyed earlier civilizations on their home planet, and therefore represent the real competition needed to inspire their civilization to advance. In the year 2301, the Kafer start an invasion of human space that will be costly to both attackers and defenders and serves as one of the major dramatic events of the game line. Mongoose ''2300AD'' altered their name to "Kaefers."
* The primitive ''Klaxun'' (''Arbors''): A species of sentient tree-like creatures native to a nearly-frozen world at the edge of the French Arm (Mongoose ''2300AD'' altered their name to "Arbors")
* The nuclear war-devastated ''Little Guys''
* The long-dead ''Medusae''
* ''Pentapods'': an amphibious species with a preference for aquatic environments, with a [[Biotechnology|biotechnological]] technical infrastructure (including starships that are massive living beings). The fact that some Pentapods show signs of [[genetic engineering]] and are treated as tools by other Pentapods masks a deeper secret regarding their origins.
* ''Sung'': a species of winged humanoids of smaller stature than humans, whose technological development is close to but not as great as humanity's in most areas; they are currently only capable of interplanetary travel. In some areas, like medical technology, interface spacecraft, lasers, and solar energy technology, they are superior to humanity.
* ''Xiang'': a species inhabiting a gas giant's moon in the Sung home star system, formerly enslaved by the Sung but now free after a brief military action by a number of human nations. Relations among the Sung are governed by a principle that the strong dominate the weak but provide the weak with requested assistance to bring them up to their masters' level, and they took advantage of the fact that the Xiang never made such requests. The Sung now consider humanity to be their superiors in this system and are chafing at humanity's refusal to improve them by showing them how to perform FTL travel.
* The ''Ylii'', a multi-species culture enslaved by the Kafers.