Copyright (c) Puzzles and Games Ring of The Archimedeans

This game was invented by the Puzzles and Games Ring of The Archimedeans in order to create a generalization of Chess.

The game uses a 18x18 Go board (or a typical Go board using the squares, not the intersections), with 43 white and 43 black stones. The game starts with this initial setup.

PIECE - A piece is any 3x3 cells square containing at least one stone, at its referred by its middle cell.

There is an exception to this definition. A piece may use a center cell outside the board (that way, Gess boards label the bottom-left cell with b2. 

RING - A piece with 8 stones, and with an empty central cell.

MOVE - The non-central stones define the move directions, and the central stone define the range.

A piece may move on a certain direction if the piece's cell on that direction (relative to the middle cell) has a stone.

If there is a stone on the middle cell, then the piece may move 1+ cells on any valid direction. Otherwise, the piece may only move up to 3 cells on any valid direction.

A piece may continue to move if there are no stones on the 3x3 cells that it crosses.

CAPTURE - If a piece occupies one or more enemy cells along its moving, they are captured and the piece's move must stop.

GOAL - A player wins if he is able to remove all opponent's rings.

Checking the initial setup, we see on each of the last 3 rows: a Rook, a Bishop, a Queen, a King (the Ring), a Bishop and a Rook. In the 6th and 13th rows, there are 6 black and 6 white Pawns.

Moving samples

The White piece centered at the stone on the left of cell [1] can move any number of cells, to the bottom and to the bottom-right. Moving to the bottom captures two Black stones, moving bottom-right captures one Black stone.

The Black piece centered on the left of cell [2] can move to the top and can capture two White stones. That piece cannot move into the top-right direction, since there is a friendly stone blocking its progression.

There is an article about Gess on Eureka Maganize N. 53. Eureka is the journal of the Archimedeans, the mathematical society of the Cambridge University.

Another game that mixes Chess and Go, is Go-Chess by Jim Callan. He also build a website to play Go-Chess online.