Series about a magical fair or bazaar

Mar 7, 2017
First read one of the books mid to late 1990s at my local library. Paperback.
It may have been several books of short stories about a fair or bazaar/market that people would travel great distances to reach. One main rule of the fair was that no magical items or weapons were allowed.
In one story a man circumvented the rules because he had a magical talent that made a dagger appear in his hand whenever threatened. Another was about a young girl who thought she had magic stones that would always land in a circular pattern when thrown, but it was actually a magical talent of her own that could predict the orbits of the planets and comets.
In one story there was a knife throwing competition that was rigged with weighted, wooden knives. A person had real knives made to look like the wooden ones so they could win, but was discovered by the local peace-keepers and either expelled from the fair or arrested.
I think at one point there was mention of a nearby ruined civilization, possibly indicating this was all post-apocalypse.