‘Then the king commanded to call the magicians, and the enchanters, and the sorcerers, and the Chaldeans so that they could tell Nebuchadnezzar his dreams. So they came in and stood before the king.'
The scene is impressive. The king called in his regular experts, ‘the magicians, and the enchanters, and the sorcerers, and the Chaldeans', all the men who claimed, and made their living by, mysterious arts and powers, and who had by it obtained a place at court. He wanted a united opinion from the experts. That this did not include Daniel and his friends was because they were new graduates and possibly not yet ‘accepted'. They were still on probation and were probably not yet seen as included in the powerful body of ‘wise men' sufficiently qualified to come before the king, which would usually be seen as a great privilege not open to all.
What he wanted from them was that they would combine together to ‘tell him his dreams'. They came unsuspectingly. They had no doubt that they would be able to interpret the king's dreams from their books of dreams. They had done it often enough before.
Some have differentiated the wise men as ‘magicians' (Hebrew - hartummim) meaning those who could divine the future by using various ritual means, ‘enchanters' (assapim) as those who could communicate with the dead, ‘sorcerers' (mekassepim) as those who practised sorcery and cast spells and used incantations, and ‘the Chaldeans' as astrologers (kasdim), the priestly caste who studied the heavens to determine the future. This is fine if we do not make the distinctions too rigid.
Some have objected to the use of the term ‘Chaldeans' in this way so early, but Herodotus certainly speaks of the Chaldeans as a well established priestly sect connected with long established festivals in about 440 BC, in a way that suggests a fairly long history.
But Nebuchadnezzar was no fool, and the previous comment in Daniel 1:20 had suggested that his confidence in them was not very high.