This game is an adaptation of a game called Ishido, which was invented in 1989 by Michael Feinberg.
The game consists of a board with 96 squares and a collection of 72 stones. Each stone has one of six symbols and one of six background colors. There are two stones with each possible combination of symbol and color.
The primary object of the game is to play all the stones onto the board.
The game begins with six stones already on the board, one in each corner and two at the center of the board. The other 66 stones are presented, one at a time, in the touchstone area to the right of the board. The game continues until all the stones have been played or until the stone presented in the touchstone area cannot be played.
To move a stone to the board it must be placed adjacent (to the left or right or above or below, not diagonally adjacent) to one or more stones already on the board according to these rules:
If it is placed adjacent to one stone it must match the existing stone's symbol or color.
If it is placed adjacent to two stones it must match the symbol of one of the existing stones and the color of the other.
If it is placed adjacent to three stones it must match the symbol of one of the existing stones and the color of the other two or the color of one of the existing stones and the symbol of the other two.
If it is placed adjacent to four stones it must match the symbol of two of the existing stones and the color of the other two. This is called a 'Four-Way'. Creating as many Four-Ways as possible is a secondary object of the game.
To move the stone from the touchstone area to the board just click on the target square on the board. The cursor switches to a pointer when it is over a valid target square. Click the 'Undo' icon under the touchstone to reverse the last move.
A little bit of extra assistance is available if you choose to use it. Click on the touchstone to get a peek at the next six stones in your pouch.
The indicators below the board keep track for you of how many stones remain in your pouch (not on the board or the touchstone) and how many four-ways you have achieved.