- "If the doors of perception were cleansed, we could see everything as it is. Infinite."
- — Random Wastrel in the Garden District
The Yam Cult is a religious cult and secret society that is based at the Mystery House on Lud's Holm. It is a monotheistic cult that worships a paranormal entity called "The Holy Yam". The Holy Yam is a floating, glowing Yam that is only visible at a specific location to those in a chemically altered state and bestows blessings upon those considered worthy.
The Yam Cult's beliefs are also somewhat of a mix between shamanism and animism, as members of the cult regularly consume Histoplasma Mushrooms to interact with what they perceive to be a spirit world beyond our own.
The Yam Cult can be viewed as a product of the situation present in the Garden District.
Over the course of the last 20 years, Wellington Wells proper has become increasingly authoritarian in its enforcement of the mandatory Joy intake of its citizens. The city mandates (by force) that everyone takes Joy and those people who either cannot take Joy or openly refuse to do so are chased out into exile in the Garden District, becoming Wastrels over time.
Left to fend for themselves, the Wastrels have taken over and occupied those buildings that still stand and installed traps to defend themselves. At the same time, the Garden District is being ravaged by a rabies-like plague that drives Wastrels insane, causing them to attack, infect and kill anyone in their vicinity.
On top of this, the Garden District has been stricken by an ever-worsening food shortage, that is now bordering on an all-out famine and there is less and less food available every day. Many Wastrels are now teetering on the brink of starvation, desperately trying to get their hands on any food still present to eke out an existence amid the filth, misery, and isolation of the Garden District.
Given the sheer lack of food, many Wastrels found themselves forced to harvest and eat Histoplasma Mushrooms to avoid starvation. These mushrooms, while edible, are also highly psychoactive, driving many Wastrels insane, resulting in the rise of the Yam Cult.
Given the deplorable living conditions of the Garden District, The Yam Cult quickly began to gain more followers among the Wastrels, as the cult provided a perverse form of unity, fellowship, and safety for its members. Eventually, the Yam Cult would go on to establish a major presence on Lud's Holm, with its main Headquarters being located at the Mystery House on Lud's Holm.
At some point prior to the events of the game, the Yam Cult gained itself a deity to focus on, when Wastrels began worshipping a paranormal entity known as "The Holy Yam". Worshippers would regularly gather on a tall hill near the Mystery House to practice a ceremony during which the Holy Yam would give blessings to those who had proven themselves worthy.
Seeking to prove themselves worthy for the Holy Yam, some Wastrels have begun attempting to practice agriculture to grow food to feed the rest of the cult. They have made some progress, having managed to produce a good first harvest, but due to the severe blight, all of the produce has rotten.