The Dark Waters of Sundara are a species of gnome from Species of Sundara: Gnomes (5E) that lives in the swamps of the world. Luck is a serious matter to these gnomes, and they will give luck gifts to others as a mark of respect or affection. Luck gifts cannot be sold, as doing so brings only bad luck.

Dark Waters Luck Gift

Wondrous item, uncommon, requires attunement

Luck gifts can take many forms, but are always a small trinket that can be carried or worn; amulets around the neck are the most common.

Luck gifts can be used once to make an unsuccessful roll into a successful one, after which they break and become unusable.

Luck gifts, if someone is foolish enough to sell them, do not work for the buyer and curse the seller with a -2 penalty on all rolls until the curse is removed.