Chaos Gate

"A sacrifice of is necessary to access the unfathomable depths of Chaos."

Chaos Gates are, as the name suggests, portals to Chaos. They appear as gateways in the floor emblazoned with an image of Chaos's eye, which open and begin emitting smoke when the room is cleared.

Health must be sacrificed in order to enter the Gate unless Chaos's keepsake, the Cosmic Egg, is equipped. This health cost increases as a run progresses, but may be offset by the effects of Chthonic Vitality. Chaos Gates cannot be entered if Zagreus does not have enough, even if he has a charge of Death Defiance remaining.

Other than interacting with Chaos and receiving their boons, it is possible for Zagreus to catch fish here. He may also encounter Nyx after the completion of the relevant minor prophecy.

Spawning
Chaos Gates will only begin spawning after 6 escape attempts. They cannot appear in shops, in boss rooms, or in the chamber immediately after a boss. Two Chaos Gates will not spawn within 8 chambers of each other. Gates grow less common in each successive area, however, a Light of Ixion can override the above conditions and cause a Gate to spawn regardless.