Goal of the game
To have the majority of stones at the end of the game.
In a square, odd-sized, game board, all board edge points are filled with neutral stones.
From there on, players take turns placing a stone of their colour in whatever free point they want, Red moving first. For the first move only, the central cell cannot be used (to avoid a known winning strategy for the first player).
If the stone a played placed is orthogonally (not diagonally) adjacent to 3 or to 4 other stones (of whatever colour: own, opponent's or even neutral), that same player has to place another stone, again in whatever free board point one likes, and so on, until the player's last placed stone is adjacent to only 2 or less other stones.
When the board is completely filled, the player with the majority of stones wins. As the total number of board cell is odd, draws are not possible.