The object of the game is to be the first player to get 4 of your pieces in line (next to each other), either in a vertical column, in a row (across), or diagonally. Your opponent has artificial intelligence. In time, you will notice that "it" develops into a more challenging opponent as it "learns". Initially, with just a little "knowledge" (FOUR.DTA), it performs well. Don't expect a dramatic change overnight. Four was written in Assembly for MS-DOS systems. CGA or better graphics is required. Uses very little memory, and no installation is required.