Nggàm is type of divination by interpreting the actions of spiders or crabs.
Derived from the Mambila nggàm ('divination')
Nggàm originated among the Mambila people of Camerron and Niger. In Cameroon, the spider of myth has a chthonic quality. Spider lives in the ground and it comes out at night. It is symbolically associated with wisdom, high rank, and the dead. The spider can cross between the world of the living and the world of the dead.
Nggàm is used to help one person in making decisions. It uses a system of leaf-cards marked with symbolic “ideograms.” The cards are usually made of tree leaves or raffia palm ribs. The ideograms are traditional symbols with specific meanings.
When a spider hole is found, the surrounding area will be cleared immediately. Usually, an old pot with a broken bottom is used to contain the spider. After hearing the question, the diviner places a set of leaf-cards along with some other objects in the pot-enclosure based on the client's query. For instance, rocks might be used to represent individual people related to the question. The leaf-cards have predetermined meanings indicated by their ideograms. Other objects, usually sticks, may be added to the mix to indicate specific factors related to the question. One or two cards are placed over the spider hole that may have special pertinence to the query. The rest of the cards are stacked.
Once the cards and objects are placed in the pot-enclosure, the diviner will rub a stone around the rim of the pot and blow into it, saying “come out, come out.” The question is chanted under the breath and the stone is tapped on the rim in rhythm with the chanting. Then the pot is covered and left undisturbed, sometimes overnight. Once enough time has passed for the spider to emerge and to rearrange the cards and objects by its movements, the lid is removed. The diviner interprets the answer by the pattern and arrangement of cards and objects.
One variation of Nggàm uses land crabs instead of spiders.