Duplo is played on an initially empty 8×8 board.

In their first turn players each deploy two anywhere on the board.

After that they take turns to expand a line of friendly units, doubling it's size. Expanding a "line" of 1 is allowed.

The extension is illegal if...

• it crosses the edge of the board
• it hits a friendly unit
• it hits an enemy belonging to an equal or longer line

If the extension meets a shorter enemy line, then...

• extend up to the first enemy
• the first enemy turns into

Play until someone cannot make a move, then the player with the most units wins!