Extispicy was a matter of state in Mesopotamia to a degree few other divinatory arts achieved. Neo-Assyrian royal correspondence shows kings routinely refusing to launch a campaign, appoint an official or even leave the palace without a favorable baru reading, and the query tablets that survive, formal questions submitted to Shamash and Adad on the king's behalf, are detailed enough to reconstruct entire foreign policy decisions from the ritual paperwork alone. The technique also traveled.
Most historians of religion accept that Etruscan haruspicy, the liver divination practiced in Etruria and inherited by Rome, descended from Mesopotamian extispicy through contact somewhere in the ancient Near East or Anatolia, a transmission visible in the strikingly similar practice of consulting a sacrificed animal's liver and in the Etruscan bronze Liver of Piacenza, a divinatory model closely paralleling the older Mesopotamian clay liver models in both function and design. Whether the transmission ran through a single identifiable route or through longer, looser contact across the Iron Age Mediterranean remains debated among specialists, but the technical resemblance between the two practices, separated by well over a thousand years and a different language and culture entirely, is treated as too close for independent invention.