Tchéilanwist

Metaphysically speaking, all tangible objects in the Feywild belong wholly to the Feywild and long to return to it, unless a fey creature formally wills them into a mortal's possession. Stolen artifacts, harvested materials, and other souvenirs taken away by mortal planewalkers all find their way back home through some method or another. However, since consumed food and drink become part of a mortal's body, this inherent draw towards the feywild takes physical and mental root in the mortals themselves once they leave the Feywild.

Tchéilanwist first manifests in the afflicted individual as a strong craving or nostalgia for the food or drink they consumed in the Feywild. If they seek out an equivalent or similar mortal item (as they often do), it becomes unpalatable to them almost instantly. Some describe this sensation as complete tastelessness, while others compare the new "flavor" of the item to mucus, seawater, or copper coins. The flavorless or "wrong" taste starts to overtake the taste and smell of all foods the afflicted person eats over the next several weeks, until no food or beverage has any other detectable flavor to them. Many people also experience muddled thoughts, fatigue, and depression when in the throes of tchéilanwist; some find themselves more prone to impulsive or rash decisions, particularly in the pursuit of pleasure.

Highly disciplined magic users, trained in traditions that emphasize restraint and self-control, are the least likely to be susceptible to tchéilanwist. Veteran adventurers such as clerics, druids, and warrior monks are the most likely to come back unaffected. (Strangely, wizards seem to be more susceptible to tchéilanwist than average, though this may be because their confidence in their magical negation abilities makes some wizards overly confident in accepting food and drink despite warnings.) Tchéilanwist is sometimes a factor that drives mortals to make fey pacts or contracts, but those already beholden to a powerful fey, such as warlocks, seem to have some resistance to the curse. In the few known instances where a Fool of the Fey has left the Feywild or broken their indenture, none have displayed any signs of tchéilanwist.   Food and drink offered under circumstance of formal invitation does not inflict tchéilanwist on mortals. However, mortals with this knowledge are sometimes lured into a false sense of security, as many highly intelligent Unseelie or Courtless fey offer verbal promises with no intent to honor them. Formal invitations only bind the fey when represented by both verbal and physical offerings, such as an engraved card or an enchanted flower whose meaning is explained to the mortal. The mortal must accept with both verbal consent and some tangible token in return, such as a drop of blood, a signature, a lock of hair, or a memory. Only food offered in such a deal, or consumed as part of a feast or banquet to which the mortal is explicitly invited in this way, can be assured to be safe.