Cleromancy, sortilege, casting lots or casting bones is a form of divination. In cleromancy, an outcome is determined or a prediction is made based on the result obtained by randomly selecting an object or by checking the way an object or a series of objects appear or are ordered. A typical cleromancy tool is rolling a die and determining the result depending on how it falls.
In Western culture
The casting of lots occurred frequently in all cultures throughout the ages. The importance or decisiveness of the result depended on the belief that the object used in casting the lot had some magical quality which allowed it to directly manifest the will or order of a god.
Casting of lots is mentioned in the Book of Joshua (vii, 14-18); the looter Akan ben Karmi is captured by dividing the tribes in stages by a lot, until the looter is captured. In the First book of Samuel (xiv, 37), Saul wants to raid the Plishtim camp at night and the priest tells him that they should go to God and ask him. However, God does not answer, which is probably an indication that the Urim and Tummim stones inside the priest's Ephod, which are used to cast a lot, did not give a clear or positive result to the query. The casting (counselling) of the Urim and Tummim as a means to determine God's will is also mentioned in the Numbers xxvii, 21-23, where Moses selects Joshua based on counselling the "judgment of Urim before the Lord."
The casting of a lot to determine God's will was also common among early Christians, as indicated, for example in Acts i, 23-26, where the apostles choose between Justus and Matthias who will take upon him the apostolic duties by casting a lot: "and they gave forth their lots; and the lot fell upon Matthias; and he was numbered with the eleven apostles." The casting of the lot was not just an arbitrary means to decide between two people, but a means by which the "Lord, which knowest the hearts of all men" can show "whether of these two thou hast chosen."
Cleromancy was a commonly used by ancient Greeks and Romans when making decisions. In Homer's Iliad (vii. 171) a lot is used to select the man who will meet the most mighty Trojan in battle. Casting of lots is frequently mentioned, usually in derogatory terms, without any connection to counselling the gods, but related to specific gods (especially Athena), who had cleromantic associations.
Pens which can answer "yes" or "no" questions are widely used in divination and fortunetelling, especially by New Age adherents. Their use is similar to the usage of pendulums for the same purpose (a pendulum can also be used for spiritism). Another classical "yes" or "no" fortunetelling method is the use of coins. There are websites which utilise software to simulate these "yes" or "no" pens to produce similar results on the computer screen.