Copyright (c) 1984 Claude Leroy

This game is played on the following 8x6 board:

Each player starts with 6 pieces off board: two singles, two doubles and two triples. 

SETUP - Each player places his 6 pieces on his second row.
TURN - On each turn, each player must move one of the pieces that are in his closest row (that row is called the shore). 
The pieces don't belong to either player. They are shared and may be moved by both players.
A single moves one cell, a double moves two cells and a triple moves three cells. 
The movement must be orthogonally sideway or forward thru empty cells (no jumps) except the last cell that may be occupied. In that case, the player must do one of two actions:
BOUNCE -  The piece occupying that cell is bounced, i.e., the player must move it (which may produce another bouncing and so on...). 
If a bouncing piece cannot move, all the move sequence is invalid.
Within a bouncing sequence, the player cannot use the same cell twice.
RELOCATE - The piece occupying that cell is placed on any empty cell behind the opponent's shore.
A player with no valid moves must pass.
The first/last rows cannot be used in a moving sequence (except as the last cell move which wins the game)
KO - A move cannot repeat the previous board position.
GOAL - Wins the player that moves one piece to the opponent's first row.

An example

North's turn. North must move the triple at a6 (the only piece on his shore). However he can win with the following bouncing sequence: a6-c5-c4-a4-a3-b1 (this last one must be a3-b3-b2-b1 and not a3-a2-a1-b1 which is invalid because the last row was used during the move sequence and not only in the last move to win).

More information about Gyges can be found here.