I think Caissus is dead on about Gothic on a 10x10. However, I disagree with him about "there is only chess." Chess has been evolving throughout the centuries and even going back a few hundred years you can see a huge number of changes in basic rules and ways the pieces move. See The Chess Artist for a nice synopsis of how each piece has evolved over time. Even Kasparov wants to change the initial starting piecs of "normal" chess to solve the death by draw problem. (See A Psychiatrist matches wits with Fritz) This solution, and most of the other chess variants that I've seen, seem very arbitrary to me. In my opinion Gothic Chess is the only logical next step in the evolution of chess.