The very, very, very first D&D tie in. An actual D&D tie in -- not Advanced D&D. (Which is why it talks of Law and Chaos. The nine-fold square does not apply here.)
But it opens with a gaming group getting a shipment of figures to use in play. One player, fascinated, takes up an exquisite one of a swordsman. And then -- our point of view shifts to that of a swordsman in Greyhawk.
In the proverbial tavern.
And another character, a berserker/wereboar, is there. Both of them wearing bracelets set with dice. They speak to each other -- and a messenger comes to them, asking them to come to his master. An elf joins them on the street, and they meet more at the wizard's. Because the wizard has noticed this, and decided to fix it by the obvious means of setting one problem at the other: the player characters' characters are now bound by spell to stop this.
It involve the undead, an illusionist, a gold dragon giving advice via a magical ring, animated shadows, and more. I dont' think it's one of her better works, but it has its interests.