Civ 4 must save/store its numerics as a 32-bit integer. 32 bits allows 4,294,967,296 values. This could be set to correspond to 1 through 4,294,967,296, or 0 through 4,294,967,295, but typically when using 32 bit integers in computers, you use the range −2,147,483,648 through 2,147,483,647, to...