Played on the The Game of Y board.
12 stones of their own color for each player, arranged alternating around the perimeter of the board.
From the website "Taking turns, players move any one of their stones by 1, 2 or 3 unit spaces along an unobstructed line, in any direction. A stone may move in only a single direction on a turn. There are no jumps and no captures of opponent pieces. When a player's stone lands immediately next to a stone of its own color, in any direction, on or within the 15 nodes of the central triangular region of the board the moving stone captures the resting stone, which is removed from the board...
To be the first player to have only one stone remaining on the board, occupying one of the 3 central nodes."