Chaos is a part of the psychic energy that composes Warp space. More generally, "Chaos" refers to anything related to Chaos, including its influence, the Gods of Chaos, their followers, and the Warp. Chaos is almost synonymous with the Warp - the two concepts are inseparable: Chaos is the limitless ocean of spiritual and emotional energy that defines the Warp. Chaos is a great and raw force of change and power, and is both physically and spiritually corrupting.[2b]
The most gifted mortals, psykers, can utilise this energy, thus making them capable of abilities which transcend the laws of the material universe. However, the malevolent power of Chaos can gradually corrupt a psyker, tainting their mind and body.[27] The iconic symbol of Chaos is the eight-pointed star.[19]
Chaos itself has many names. The Eldar, for example, call it the Primordial Annihilator.
The Realm of Chaos was formed as the emotions of mortals (be they anguish, desire, hatred, or pride) pooled together in the psychic mirror-reality of the material universe known as The Warp. Such was the power of these emotions that they eventually formed creatures which, over time, gained sentience, resulting in the birth and rise of the Gods of Chaos. As the races of the material universe grew, so too did their hopes, dreams, rage, wars, loves, and hatreds. All of these raw emotions served to fuel the growth and power of the Chaos Gods. Eventually, the gods reached back, into the dreams and desires of mortals, and since that time they have been working to influence the physical realm and its myriad races.
Chaos and its realm exists far outside of imagination; an impossible abstraction made real only by metaphor and the roiling emotions of the minds of mortals. It is constantly reborn, eternally shifting. Within this realm titanic hosts made purely of energy and emotion clash as the Gods of Chaos wage their endless Great Game. The Chaos Gods and their dominions are one, for both are formed of the same Warp Energy. As the Gods gain power, their realms expand. However the Gods are not alone, for they have countless servants made of their own essence known as Daemons. The beings of the Warp have no true physical forms and even Daemons are simply taking a skin or bubble of appearance that is a projection of their God. The Realm of Chaos is a fantastical landscape devoid of consistency and unbound by the laws of time and space, a random, unstructured panorama of pure energy and unfocused consciousness. It is from this nature that it is dubbed Chaos, for it is Chaotic in the truest sense.
The Realm of Chaos and the Material Universe can overlap, often with devastating consequences for mortals. Warp Storms and Warp Rifts are such examples of a breach between these two realities.