The Star of Chaos, the primary symbol for Chaos in the Known World.
The term Chaos Undivided refers to a faction among the forces of Chaos that serves the pantheon of the major Chaos Gods as a whole rather than owing complete fealty to one over the others. It is often represented by the Everchosen of Chaos, the mortal Chaos Lord who is the greatest champion of all the major Chaos Gods.[1a]
Followers of Chaos Undivided venerate the force of Chaos itself, sometimes as an entity that some insane scholars of the Old World name the "Great Beast," in which the major Chaos Gods are seen as a single deity whose four major constituent parts are to be worshipped equally as different emanations of the same universal force. At times, this entity sets aside its mad internal struggle, which is otherwise known as the Great Game, to make it possible for the fragmented armies of the major Chaos Gods to gather together under one banner, such as during the various Chaos incursions into the Known World like the Great War Against Chaos and the End Times. These moments cause the Old World to tremble and quake in fear and loathing.[1a][2a]
Of all the servants of Chaos, the worshippers of Chaos Undivided serve Chaos in its purest form. They can interpret the meaning of Chaos in a variety of ways, including as a single god or force like the Great Beast, venerate the four major Chaos Gods equally but still as fully separate entities, or simply favour one slightly over the others.
Icon of the Daemonic Legion of Chaos dedicated to Chaos Undivided and led by the Daemon Prince called the Godslayer in Total War: Warhammer III.
For those who prefer to view Chaos as a unified whole in one guise or another, the various Ruinous Powers are instead seen as the different aspects of a single god of Chaos. These individuals may still choose to give their service to one Chaos God in this schema but are likely to never gain much favour with an individual power because of their veneration of Chaos as a whole.[1a]
Finally, others seek to use the power offered by Chaos simply as a means to their own ends, without the pretense of worship or veneration. This is an often risky path and only two outcomes exist, the attainment of Daemonhood through extraordinary success in achieving the goals of Chaos or ultimate damnation as a Chaos Spawn and the devouring of one's soul by the Ruinous Powers upon death.
However Chaos is viewed, the followers of Chaos typically come together under the banner of a particularly powerful and charismatic leader of Chaos Undivided during Chaos incursions. This periodic unification is often achieved under the command of the mortal Chaos Lord known as the "Everchosen" who represents the interests of all the Chaos Gods and seeks the ultimate destruction of the mortal world. [1a]
Driven by dreams of mayhem, loot, and glory in battle, the forces of the various factions of Chaos set aside their differences for a short time to fight side by side. The people of the Old World know that it's just a matter of time before another leader inspires the hordes of Chaos Undivided to come together yet again. Whether there exists a Great Beast or not is subject to much debate, but certainly the effects of the Chaos incursions unleashed by the various Everchosen over the millennia are undeniable.[1a]