First chose a difficulty by typing ‘beg’, ‘int’, ‘adv, or ‘exp’ – Beginner is 15 degrees, Intermediate 10 degrees, Advanced 5 degrees, and Expert 2.5 degrees. A grid of your chosen square size will be placed randomly on the map. Then, enter the largest city (min 50K population) in each grid square of the size based on your difficulty. Green squares contain answers. Adv and Exp levels may take a few moments to load.