SQUARUBORUS

[variant of Ouruborus] Players take turns moving both ends of the slime-worm, each to some adjacent cell. After each move, each end leaves a stone of that player's colour. The worm may not move onto a coloured cell.

If at some point before the board is full, a worm-end cannot move normally, the players continue, making single moves if necessary, until the next player who is able to must split the other end into two heads.

A player wins if he makes a 4 in-a-row with his stones (ortho or diag). If both ends become blocked simultaneously, the last player to move wins.

Sample Game:

J starts: sw.se w.ne n.s e.nw n.n n.ne w.n w.se
ne.se n.s sw.s sw.se se.s s.w s.nw s.s ne.w? e.n & wins

Final Position:

. . b . . . . .
. j j b j b . .
b b j j j b . .
. j j b b b j .
. b b j j j b .
. j J B . . j .
. b . . B j . b
. . . . J b b j