The most popular game among the many peoples of Kregen, world of Antares, is one that resembles chess, called Jikaida. Jikaida is a battle of wits and war game pieces that suited well the tension charged atmosphere that enveloped Dray Prescot. For reconquering Vallia was assuming the aspect of such a game--move versus countermove, horde against horde! Then Dray Prescot found himself no longer in control of just a game--he had become a living chessman on a real-life board at the dreaded arena of Jikaida City. There every move was accompanied by bloodshed and behind every game might hang the fate of a city, an island, or even a nation!
A Sword for Kregen, by Alan Burt Akers (AKA Kenneth Bulmer): This is the first Dray Prescot book that I ever read, and it is still my favorite. Dray Prescot meets a better swordsman than he is, which was unique in my experience with Sword & Planet fiction up to that time. The book also involves a game of living chess, or the Kregen equivalent of that, called Jikaida. I still remember finding this book at a small used bookstore in Russellville, Arkansas when I was in college there. Just a great story.
If you are a John Carter of Mars fan or enjoy the "displaced person on another world" then this series is for you. The books run in long story arcs so you can read just a few to complete a plot line or go for the whole set. Akers creates a very complex world for the hero to adventure in. Recommended