Trial by ordeal was an ancient judicial practice by which the guilt or innocence of the accused was determined by subjecting them to a painful, or at least an unpleasant, usually dangerous experience.
In medieval Europe, like trial by combat, trial by ordeal, such as cruentation, was sometimes considered a "judgement of God" : a procedure based on the premise that God would help the innocent by performing a miracle on their behalf. The practice has much earlier roots, attested to as far back as the Code of Hammurabi and the Code of Ur-Nammu.
Water-ordeal; miniature from the Luzerner Schilling
After being accused of adultery Cunigunde of Luxembourg proved her innocence by walking over red-hot plowshares.
Peter Bartholomew undergoing the ordeal of fire, by Gustave Doré.
Sita in an agnipariksha, Yuddha Kanda
Trial by combat was a method of Germanic law to settle accusations in the absence of witnesses or a confession in which two parties in dispute fought in single combat; the winner of the fight was proclaimed to be right. In essence, it was a judicially sanctioned duel. It remained in use throughout the European Middle Ages, gradually disappearing in the course of the 16th century.
A 1540s depiction of a judicial combat in Augsburg in 1409, between Marshal Wilhelm von Dornsberg and Theodor Haschenacker. Dornsberg's sword broke early in the duel, but he proceeded to kill Haschenacker with his own sword.
Depiction of a judicial combat in the Dresden codex of the Sachsenspiegel (early to mid-14th century), illustrating the provision that the two combatants must "share the sun", i.e. align themselves perpendicular to the Sun so that neither has an advantage.
Depiction of a judicial duel between a man and a woman by Hans Talhoffer (Ms.Thott.290.2º, Folio 80r, 1459)
Kalaripayattu Combat