The Name of the Game — Rose Estes

GREYHAWK...

A mysterious and spellbinding boardgame has conquered the realm of Perrenland. The king has wagered his throne and lost, the beautiful Princess Linnea finds herself without a royal suitor, and the minions of neighboring Tusman are poised for a deadly invasion.

Into this scenario strays our hero, Mika, shaman of the Wolf Nomads, with his magic gemstone and unpredictable demon hand.

Mika is metamorphosed into a griffon and finds himself acclaimed as a prince. Lost behind enemy lines, naked, and deserted by his bonded wolf companion, Tamitir, Mika must overcome hippogriffs, stone giants, and the usual assortment of trolls, gnolls, ores, and harpies, plus an entire army of monsters,
in order to save the kingdom -- not to mention himself.