Sphere of Influence

Starmap from 2158 showing Spheres of Influence.

A Sphere of Influence is the area shown on the starmap that roughly indicates the territory controlled by a specific race. The center of the circle is the approximate center of the race's forces and the size of the circle indicates their military strength. The circle itself, as viewed on the starmap, can be interpreted as the border, such that Battle groups from the given race will chase any alien vessel crosses in. If the interloper leaves the Sphere of Influence, any pursuing battle groups will eventually break off pursuit and vanish from the tactical display;¹ the exceptions to this rule are the Slylandro Probes and the Melnorme which can appear anywhere in HyperSpace.

A player can effectively watch an entire race move by entering and exiting the Map, as the displayed spheres will move upon opening it each time (though the actual Spheres of Influence move independently of this). Notable examples of this movement are the movement of the Pkunk to rejoin the Yehat, the movement of the Ilwrath to attack the Thraddash, the Supox and Utwig offensive against the Kohr-Ah, the Mycon Birthing Fleet's voyage to implant a Deep Child beneath the crust of Organon I and the Kohr-Ah after they win the Doctrinal War and begin their Death March.

The Chmmr, Humans, Melnorme, Slylandro and Syreen are the only sentient races who do not have spheres of their own.

Sphere Colours

Grey	Ur-Quan Kohr-Ah
Green	Ur-Quan Kzer-Za
Teal	Pkunk, Thraddash, Utwig
Blue	Arilou, VUX
Mauve	Yehat Rebels
Violet	Umgah, Yehat, Yehat Royalists
Purple	Ilwrath, Mycon, Orz
Red	Druuge, Zoq-Fot-Pik
Brown	Supox
No Sphere	Chmmr, Human, Melnorme, Slylandro, Syreen,

Notes and references

¹In the game, the battlegroups may spawn anywhere, not necessarily on top of a stars' gravity wells, and likewise disappear anywhere. It is unknown if this is a gameplay simplification/inaccuracy, or if the battlegroups actually return to TrueSpace and are undetectable by Hyper-Radar there.