For more information about this specification contact Tim Prime, email@example.com.
For more information on the game see Eureka.
Point and Stone are the same. Gess uses the same coordinate system as Go GM, two lowercase letters. The first letter is the horizontal dimension; the second is the vertical.
The "edges" of the Gess board are placed so that one row/column of points lays outside each edge. The default board size is 20x20 (18x18 inside the "edges").
A move is a pair of points, which are the centers of the "from" point, a colon ":", and the "to" point of the 3x3 piece being moved. It is illegal for either of these points to be on the parimeter (outside the "edge").
Viewers are responsible for checking the colour of the stones in the 3x3 region at the "from" point. All stones must be the same colour, that of the player making the move. Otherwise, the move is illegal.
There are no additional Gess specific properties.