The poison oracle is the preferred way for the Azande of Central Africa to determine whether a particular mishap is due to the action of a witch. The operator uses certain mechanisms to discover hidden truths. In the case of the poison oracle, a poisonous substance known as benge is administered to a chicken by the operator. Following the administration of the poison, a series of questions is posed by the questioner to determine the results.

Example: A question such as "If X is bewitching Y, oracle, stick." The question may be repeated in inverted form to check the accuracy of the oracle: "If X is bewitching Y, oracle, do not stick.

The chicken is either unaffected by the poison or, more frequently, has violent spasms. Sometimes the chicken dies and sometimes it survives. The manner in which the chicken reacts to the poison is interpreted as indicating the presence or absence of witchcraft.