Diggrie

Diggrie is a two-player game played on a 5x5 grid, with each player having five flat discs and one taller king disc in their color. To win, you must create in your color a row of four pieces or a square of pieces. You can move over unoccupied spaces; jumping is not allowed. The game includes three variants, and if you include the king piece in play, it needs to be part of the winning row or square.