It is certain, for the Archaic period, that oracles at most Apollonian oracles were given on the basis of the prophetic properties of the water of a sacred spring and the ecstatic theolepsy of the female priest. But in earlier ages it was the method of sacred lots or dice (thriae) that was followed. This method, probably also used at Delphi, consisted in the drawing of a prophetic pebble from a receptacle containing many pebbles each different from the other. The oracle was given based on the symbols of the pebble. A similar practice was in use up to Classical times at the shrine of Heracles at Boura in Achaea, but there the pebbles had been replaced by knucklebones (astragaloi). The worshipper cast four knucklebones and subsequently got an answer with the aid of a table that gave the meaning of every possible permutation.

One of the most ancient methods of prophecy in the Hellenic world, and indeed the most important for centuries, was augury. This method had come to the Hellenic world from Assyria and Babylonia. It was practised by Tiresias, by the renowned Calchas, he who accompanied the Achaeans to Troy, and was the method carried out at the most ancient and venerable Hellenic oracle, the shrine of Zeus at Dodona. There the priest followed the flight and behaviour of the peleiai (doves) that perched on the sacred oaks. The oracle was given in symbols and not in words, as was also done at the oracle of Zeus Ammon in Libya. Herodotus mentions the common provenance of both these oracles (2.54-55). The oracle at the Siwa oasis was certainly of Egyptian origin, but from very early on it came under the control of the Greeks of Cyrenaica. Augury was practised at other shrines too. Looking northwards, the prophet would take as a good sign the appearance of an oionos (a bird of omen) from the east; and as a bad sign, from the west. The oracle was specialised according to the bird-species and the flying pattern. Birds particularly looked at were the eagle, the hawk, the owl, and the heron.

Hieroscopy or hieromancy also comes from the Orient, and was certainly practised in Babylon. Normally it is a case of prophecy based on observation of the entrails of the sacrificial animal. A special category, hepatoscopy, was very popular among the Etruscans. In the Hellenic world other versions of hieromancy were commoner: such as pyromancy and capnomancy. The former entailed watching the fire and the remains of the sacrifice; the latter, watching the smoke. In certain cases they also observed the behaviour of the animal being led to sacrifice. The Ismenion at Thebes and the shrine of Zeus at Olympia both gave fire prophecies. Another prophecy method of Oriental origin was lecanomancy, mentioned by Aeschylus (Agamemnon 322-3). The oracle was given through the observation of ripples or reflections on a water surface. Similar was the method of prophecy for people who were ill that was practised at the temenos of Demeter and her Daughter at Patra. Having prayed and burned incense, the worshipper would look into a mirror hanging above the still waters of the sacred spring, where he could see himself alive or dead.

Another special category of oracles was those where the divine oracle was revealed to the worshipper in a dream. All of these were connected with curing and with therapeutic deities or heroes. The worshipper had to fall into a slumber (egkoimese) in a holy place, precinct or sanctum (abaton), and whatever dreams he had revealed to him the outcome of his illness. This was how the Amphiareum at Thebes and the Amphiareum at Oropus worked. It was a method common at many shrines of Asclepius too, the best-known of them being, of course, Epidaurus. There the worshippers lay down in the enkoimeterion or sanctum and waited for the godsent dream. Very often, indeed, the experience of the dream was at the same time a cure. Analogous was the functioning of the dream oracle at Oetylus in Laconia; the Charonian cave, sacred to Demeter and her Daughter, at Nysa in Caria; and the cave oracle of Trophonius at Lebadea. At the last-named, the worshipper was subjected to a series of rituals the climax of which was the nocturnal crawl (eiserpyse) into the cave's narrow, labyrinthine passages. On emerging, the worshipper would tell the priests what he had seen and heard. They provided an interpretation, though in reality what had most effect on the worshipper was the his emotional disturbance from the test.

The necyomanteum or psychopompeum worked on the same principle. There the worshippers, having sacrificed to the chthonian gods, invoked the shades of the dead, from whom they would receive an oracle. The most celebrated necyomanteum was at Ephyra in Thesprotia, not far from the mouths of Acheron.