This Crossnull is a version of Renju. The game is played on a 15 x 15 board. The first player places a cross piece on an empty cell by turn, the second player places a null. The one who place five pieces in a row (vertically, horizontally or diagonally) first wins. In case all board is filled, and the row of five identical pieces is not made, the drawn game appears. Simple and intuitive interface makes it easy to control the game using the mouse only.