How will you keep tack of the game board? Without an array you would have to have 9 variables Board1 to Board9, or maybe Board11 to Board33 if you want to have implied rows and columns. With arrays you could just declare Board[9], or perhaps better Board[3,3]. Now lets say you want to check for three in a row horizontally or vertically. With arrays you can do two for loops one that looks at rows