For the use of random selection as a way to make a fair form of selection, see Sortition.
Cleromancy is a form of sortition, casting of lots, in which an outcome is determined by means that normally would be considered random, such as the rolling of dice, but are sometimes believed to reveal the will of God, or other supernatural entities.
Casting of lots occurs relatively frequently in the Bible, and many biblical scholars think that the Urim and Thummim served this purpose. In the Hebrew Bible, there are several cases where lots were cast as a means of determining God's mind:
In the Book of Leviticus16:8, God commands Moses, "And Aaron shall cast lots upon the two goats; one lot for the LORD, and the other lot for the scapegoat."
In Joshua 7, a guilty party (Achan) is probably found by lot and executed.
In the Book of Joshua18:6, Joshua says, "Ye shall therefore describe the land into seven parts, and bring the description hither to me, that I may cast lots for you here before the LORD our God." This action is done in order to know God's will as to the dividing of land between the seven tribes of Israel who had not yet "received their inheritance." (Joshua 18:2).
Also in the First Book of Samuel14:42, lots are used to determine that it was Jonathan, Saul's son, who broke the oath that Saul made, "Cursed be the man that eateth any food until evening, that I may be avenged on mine enemies." (1 Samuel 14:24).
In the Book of Jonah1:7, the desperate sailors cast lots to see whose god is responsible for creating the storm: "Then the sailors said to each other, “Come, let us cast lots to find out who is responsible for this calamity.” They cast lots and the lot fell on Jonah."
Other places in the Hebrew Bible relevant to divination:
Book of Proverbs16:33: The lot is cast into the lap, but its every decision is from Yahweh and 18:18: The lot settles disputes, and keeps strong ones apart..
Book of Leviticus 19:26 KJV "... neither shall you practice enchantment, nor observe times." The original Hebrew word for enchantment, as found in Strong's Concordance, is pronounced naw-khash' in English. The translation given by Strong's is "to practice divination, divine, observe signs, learn by experience, diligently observe, practice fortunetelling, take as an omen"; and "1.to practice divination 2.to observe the signs or omens". Times in the original Hebrew is pronounced aw-nan' in English. Its translation in Strong's is "to make appear, produce, bring (clouds), to practise soothsaying, conjure;" and "1. to observe times, practice soothsaying or spiritism or magic or augury or witchcraft 2. soothsayer, enchanter, sorceress, diviner, fortuneteller, barbarian...". In the Hebrew-Interlinear Bible, the verse reads, "not you shall augur and not you shall consult cloud".
Deuteronomy18:10..let no one be found among you who [qasam qesem], performs [onan], [nahash], or [kashaph].qasam qesem literally means distributes distributions, and may possibly refer to cleromancy. kashaph seems to mean mutter, although the Septuagint renders the same phrase as pharmakia (poison), so it may refer to magic potions
In the Book of Esther, Haman casts lots to decide the date on which to exterminate the Jews of Shushan; the Jewish festival of Purim is a remembrance of the subsequent chain of events.
To Christian doctrine perhaps the most significant mention of lots is in the Book of Psalms, 22:18 "They divide my garments among them, and for my clothing they cast lots." This came to be regarded as a prophecy connecting that psalm and the one that follows to the crucifixion and resurrection of Jesus, since all four gospels (for example, John 19:24) tell of the Roman soldiers at Jesus's crucifixion casting lots to see who would take possession of his clothing. (That final act of profanation became the central theme of "The Robe", a 1953 film starring Richard Burton.)
In the Eastern Orthodox Church this method of selection is still occasionally used. In 1917 MetropolitanTikhon was elected Patriarch of Moscow by the drawing of lots. In the Coptic Orthodox Church, drawing lots is still used to choose the Coptic Pope, most recently done in November 2012 to choose Pope Tawadros II. German Pietist Christians in the 18th Century often followed the New Testament precedent of drawing Lots to determine the will of God. This was often done by selecting a random Bible passage. The most extensive use of drawing of Lots in the Pietist tradition may have been Count von Zinzendorf and the Moravian Brethren of Herrnhut who drew lots for many purposes, including selection of church sites, approval of missionaries, the election of bishops and many others. This practice was greatly curtailed after the General Synod of the worldwide Moravian Unity in 1818 and finally discontinued in the 1880s.
Tacitus, in Chapter X of his Germania, describes casting lots as a practice used by the Germanic tribes. He states:
"To divination and casting of lots, they pay attention beyond any other people. Their method of casting lots is a simple one: they cut a branch from a fruit-bearing tree and divide it into small pieces which they mark with certain distinctive signs and scatter at random onto a white cloth. Then, the priest of the community if the lots are consulted publicly, or the father of the family if it is done privately, after invoking the gods and with eyes raised to heaven, picks up three pieces, one at a time, and interprets them according to the signs previously marked upon them."
In the ninth century Anskar, a Frankish missionary and later bishop of Hamburg-Bremen, observed the same practice several times in the decision-making process of the Danish peoples. In this version, the runes were believed to determine the support or otherwise of gods, whether Christian or Norse, for a course of action or act. For example, in one case a Swedish man feared he had offended a god and asked a soothsayer to cast lots to find out which god. The soothsayer determined that the Christian god had taken offence; the Swede later found a book that his son had stolen from Bishop Gautbert in his house.