"The comparison has been made between war and chess [...] I find the comparison to be false [...] Once, perhaps, it was. On Old Earth, back in the mists of time. Two equal opponents, with equal forces, on a level playing field. [That is no longer the case.] First, the opponents are hardly ever truly seen. [...] Second, is the idea of equal forces. [...] Third is the idea of a level playing field. The chessboard is limited to an eight-by-eight grid. There is nothing beyond this little universe. No ninth rank. No green pieces that suddenly sweep onto the board to attack both black and white. No pawns that suddenly become bishops. [Pawns only promote] by advancing through all the spaces of its row, under fire the entire time. It doesn't suddenly blossom into a queen by its own volition. No, chess is nothing like war, which is one of the reasons I play it. It's so much simpler than real life."
-Arcturus Mengsk in Jeff Grubb's StarCraft: Liberty's Crusade
I did a bit of modifying to make it into a self-supporting monologue, as the conversation is a bit of a dialogue in the actual novel; luckily, the other speaker is mostly just posing small questions, so I was able to just rework his words into the brackets. Also, I removed a lot of detail from Mengsk's first two points, as they're heavily reliant on one having knowledge of StarCraft lore.