1 Samuel 28:6 NIV
"He inquired of the LORD, but the LORD did not answer him by dreams or Urim or prophets"
1 Chronicles 10:14 NIV
"and did not inquire of the LORD. So the LORD put him to death and turned the kingdom over to David son of Jesse."
Aha! There is a contradiction in the Bible! Except, this isn't it. How come? Lets first of all get the Hebrew correct before we move onto what it means contextually.
1. It's not the same word.
1 Sam. 28:6 uses the Hebrew "way-is-al" translated in the NIV as "inquired" and 1 Chron. 10:14 uses the word "a-ras" translated as "inquired". Why is a different word here translated here as the same word? Because the English word carries a double nuance, one that is present in one Hebrew word, the other which is present in the other Hebrew word. Translation commitees often translate verse by verse, stopping at a word, amd voting on what its dynamic equivalency is in the English. Particularly the NIV is a "thought for thought" or dynamic translation, but considering the NASB also uses the same word for both cases, and it itself is a "word for word" translation there must be a good reason why.
The Hebrew word "way-is-al" in itself carries the nuance of "asking", based on verses that translate the same word. "Inquiring" is asking, so there is nothing wrong with this translation.
Inquiring also holds a little known nuance of "discovery". The asking of the question, is part of a larger process of discovery, and not simply seeking permission. This definition fits well with the Hebrew "a-ras". Which can only mean that, the translation committee wanted to ensure that this "pondering, investigating, discovering" nuace is presence in the best fit equivalent word, and "inquiring" is not a horrible choice, since its context would dictate its full meaning, or the nuaces in carries as you read in English. Except for when you translate different words conveying the different nuance, into the same English word, and it leaves a lot of guess work and possibility of bad contextualization, and simply the wrong meaning open to the reader.
Since we know the proper nuaces now, returning to examine the meaning in context should prove fruitful.
2. In context, 1 Sam. is saying that Samuel asked God flippedly what he should do. In 1 Chron. Saul didn't "seek God" spiritually, with his whole heart, since he didn't wait for God's response after asking, and sought out the medium instead of God. But he "inquired" in both passages hypothetically, if that only means asking. Since "a-ras" carries the nuance "to seek out", and in context, to discover God's will and purpose, this is clearly something Saul didn't do when he simply asked God to give him revelation. If that was the case Saul would have waited for God's response, trusting God, even if it was not a response in his favor. Waiting might have meant losing, but since Saul had already determined what he wanted to do, even after Samuel tells him otherwise, Saul goes out and does it. Second, going to the witch, was clearly a violation of God's law, not something someone seeking God would do.
That is the reasoning behind the Chroniclers use of the word and is therefore proper. Simply asking God for revelation is not enough to qualify for "a-ras". Rather "a-ras" means you have a determination and trust behind your seeking, something Saul clearly lacked in both books.
Another place where A-ras is used gives us a clue as to its fuller meaning.
2 Chronicles 17:3-4
"The LORD was with Jehoshaphat, because he walked in the earlier ways of his father David. He did not seek* the Baals, but sought* the God of his father and walked in his commandments, and not according to the practices of Israel."
Here it becomes clear that the nuance behind the "a-ras" is a trust in the Lord.
See also "a-ra-su": Psalm 119:155; Isaiah 9:13
"All Scripture is God-breathed..."