Selections of jurors and magistrates in ancient Greece

 A kleroterion (allotment machine) allowed for the random selection of dikastes, jurors and other officials, needed in civic proceedings in ancient Greece.  Prior to 403 BCE, courts published a schedule and number of dikastes required for the day. Those citizens who wanted to be dikasts queued at the entrance of the court at the beginning of the court day and dikasts were selected on a  "first come, first served basis."  Beginning in 403 BCE, however,  Athenian allotment underwent a series of reforms, and from 370 BCE onwards, a kleroterion was employed. Along the front of the machine there were columns of slots representing the Athenian tribes.  A pinakion (juror's ticket) bearing the name of a potential official was placed in each slot of the appropriate tribe's column.  The archon then placed a mix of black and white dice (kyboi) into a tube along the side of the kleroterion. The number of white dice was proportional to the number of jurors needed. The archon allowed the dice to fall through the tube and drew them out one by one. If the die was white, the top row, one citizen from each tribe, was selected as jurors. If the die was black, the archon moved on to the next row down from the top and repeated the process until all juror positions were filled for the day. 

At the beginning of each year, Athenian citizens who were eligible to serve on juries or in other important positions received a small bronze ticket with their name, their father's name, and the name of their tribe.  This pinakion bears the words, "Philomnestos from the deme (district) of Ikarion, in the region of Mt. Pentelikon," and features two stamps depicting an owl and a Gorgon.  Traces of earlier inscriptions suggest that it had already been re-used at least six times.

A kleroterion found in Hadrian's Gymnasium, 162-161 BCE from the Epigraphical Museum in Athens photographed at the exhibit "The Greeks" presented at the Field Museum in Chicago, Illinois

A bronze pinakion dating to the 4th century BCE found in the ancient agora of Athens, from the Museum of the Ancient Agora in Athens photographed at "The Greeks" exhibit presented at the Field Museum in Chicago, Illinois in 2016.