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human
[Dungeons & Dragons] What are Ioun Stones, and what do they do?

I've seen Ioun Stones floating around in D&D and Pathfinder and stuff, and I still don't quite...get them? I think they come from Jack Vance, but my memory's hella fuzzy on all of that. 

So...what's the deal with Ioun Stones?
gpt
The initial mention of a IOUN stone is Rhialto the Marvellous. Rhialto is sent on a journey to find Morreion, who is looking for magic-annulling IOUN stones.

Interestingly, the invention of Ioun stones is Congenio Ioun, who was one of the first wizards of the Realms to enchant items of any kind. 

**Doyalist:** Because it should be said, Gary got the permission of Jack Vance to incorporate Ioun stones into D&D, and they were first introduced in The Strategic Review #4 in 1975.