The Ritual was created by Iggwilv and written down into her Demonomicon.
It is a long and strenuous Ritual. It must be done by a single arcane spellcaster, and takes six hours to perform. The Ritual it must be started at sunset and must be done on a night of power. This could be an important astral conjunction, the anniversary of some important arcane event, or simply a solstice or equinox. During the course of the six hours, the spellcaster performing the ritual must cast the wish spell three times, whether that be from a scroll or by preparing it.
The Ritual requires a massive amount of mundane material components. The list of material components and when exactly they are used is the most extensive portion of the Ritual text. These material components are everything from a live spider to a thirty foot diameter plate of pure silver. The mundane material components cost a grand total of 2.5 million gold pieces and could stock ten magic shops.
The Ritual also requires thirteen hard to obtain components that represent different parts of the magical world. They are all vague and require either a significant portion of a creature strongly aligned with the component or a powerful magic item. A powerful monster is something on the order of a great wyrm dragon or a powerful outsider. A powerful magic item is an artifact or some worth at least 200,000gp.
The thirteen components are:
The first eight represent the material plane and arcane magic. These each must be a large portion of powerful mortal creature that is strongly aligned with the element or a powerful magic item. This portion could be an arm or a leg, but is preferably a soul. The creature doesn’t necessarily have to die for the component to be taken, but most would object to a leg being taken. For the magic component, it has to be from something that drains magic, such as something that can dispel magic as a spell-like ability. These requirements can also be fulfilled by a powerful magic item that is associated with the element. Iggwilv fulfilled obtained these components by killing great wyrm dragons and trapping their souls.
The next four components represent the outer planes and divine magic. They each must either be the soul of an outsider with the subtype, or a powerful magic item associated with the alignment. There must be a total of four components and something with two subtypes can only apply to one of the components. Iggwilv used two pit fiends, a balor, and a holy avenger for these components.
The last component represents the mortal who bridges the gap between the material and the spiritual. This component can only be filled by the body and soul of a powerful, mortal spellcaster. The spellcaster does not need to be willing or alive, but both the body and soul must be present at the time of ritual. Iggwilv killed the high priest of Graz’zt in Oerth and then trapped his soul.
All material components are completely used up over the course of the ritual. If Ritual is interrupted, a portion of the mundane material components is used equal to the amount of time left.