Two
players. One
player
takes black, the other white. Both take turns to
place a
piece of their colour on the board shown above and aim to form a
connected chain
of pieces that links opposite sides of the board. The player
with
the black pieces aims for a vertical connection, the other player aims
for a horizontal connection. The nodes in the corners of the
board
are common to both adjoining edges. Black ( vertical ) goes
first.

**The Midpoint Rule**. A player may play at the midpoint
of a 'square' only if none of the four corners of the square are
occupied. In the following diagram neither player may play on any of the nodes
marked
A to F. The other midpoint square nodes are playable.

*(
Invalid
midpoint moves. )*

**The
Capture
Rule** Pieces can be 'captured' during
the course of a game. If the midpoint node of a
'square' is
unoccupied a player can capture by completing a configuration in which
all four corners of the square are occupied with both players occupying
opposite corners of the square. The other player's pieces are
then
removed from the square. In the following diagram white can
play
on the node marked A to capture the two black pieces in the
square. White can play at B, but this does not capture since
the midpoint node is occupied.

*(
Capture,
before and after. )*

**Double Capture**. A double capture is
allowed. In the following
diagram white captures
four black pieces with one move at the node marked A.

*( A
double
capture, before and after. )*

**The Swap Rule**. The second player ( white, horizontal
) has the option to swap colours immediately after the first
player has made
his first move ( black, vertical. ) If swapped the roles will
be reversed. The first player will take the white pieces, will
have
to aim for a horizontal connection and will play against his own first
move. The second player is given a swap option in order to
counter
the first play advantage that the first player would otherwise have.

**Variations**. There
are two variations. A game
can start either with each player having four starting pieces at the
edges of the board ( standard variation ) or with an empty board ( open
variation ).

*( Standard variation. Initial layout with
starting pieces. )*