Copyright (c) 2002 Joao Pedro Neto

This game is played on two empty 7x7 square boards.

  • LIBERTY - A stone is free if it is orthogonally adjacent to an empty cell, or is adjacent to a friend stone with liberty.
  • SWAP - A stone can swap its position to the same cell on the other board, if that cell is empty.
  • PIE RULE - One player places 3 black stones and 2 white stones on some empty cells. The other player choose sides. White drops the next cell, then turns alternate.
  • TURN - On each turn, each player must do one of the following things:
    • Pass his turn;
    • Swap a stone (removing all stones without liberty) and then drop a stone on an empty cell (removing all stones without liberty). 
      • Swapping is mandatory but dropping is not.
      • If a player cannot swap one of his stones, then he can swap an opponent's stone.
      • It is not valid to create a position where no swaps are possible.
  • GOAL - The game ends when both players pass. Wins the player with more points.
    • A stone counts as one point, and a cell inside the player's own territory counts also as one point (same as Chinese Go rules)
An example

Black's move. The marked black stone has only one liberty (to its left; the cell on the other board does not count has one). Black swaps the marked stone to [2] and drop a stone at cell [1] capturing the white group.

As easily seen, this game is a mix of Go with a wonderful game, Alice Chess. Notice that the rules permit suicides, which can be useful when there is no better move left, and a drop is essential.