Close more boxes
Take turns drawing one edge between neighbouring dots on the five-by-five dot lattice. Select an open horizontal or vertical edge; diagonal lines are not moves. Four edges enclose a box. The player who completes its final side claims that box.
Keep your extra turn
Completing a box gives you another turn. One edge can close two neighbouring boxes, claiming both while still granting one next choice. Keep playing while your edges complete boxes. If an edge completes none, the turn passes to the computer.
Count the finished squares
The board contains sixteen boxes. Play finishes when every edge is drawn, and the player with more claimed boxes wins. Equal counts draw. Ownership marks distinguish both sides. You cannot redraw an occupied edge or remove an edge during ordinary play.