Copyright (c) 2002 William Wragg 

This game is played on the following board.

White starts with 6 stones off board, and Black starts with 15 stones off board.

STACK - A stack of 1 to 6 stones of either color.
Two stacks of four or more, with the same colored (either temporary or permanent - check below) safe stones on top cannot be adjacent to one another!
TEMPORARY SAFETY - Two stones of the same color stacked directly on top of one another are temporarily safe
The top stone can only be moved by the player who owns it.
Both players can still place additional stones on top of temporarily safe stones.
PERMANENT SAFETY - Three stones of the same color stacked directly on top of one another are permanently safe when on a RED circle.
The top piece cannot be moved by either player.
Both players can still place additional stones on top of permanently safe stones.
TURN - On each turn, each player must do one of the following things:
Drop a stone of his color on any empty cell, except the central one.
If there are less black stones than white stones on the board, Black must drop a stone (if he still have them). 
Move an unsafe stone of either color.
A stone on top of a stack of size N can move to the top of an adjacent stack of size less or equal to N+1.
A stone can move to an empty cell.
No stone from inside a stack may be moved. 
KO - A player may not move a stone just moved or entered by the opponent.
GOAL - Wins the player that makes the last move.
White also wins by creating a stack of size 6. 

Some notes from the author: The color of the pieces only matters when entering a piece, or making safe pieces. Other than these the pieces can be viewed as common, and can be moved by either player. For beginners it is easier to play white than black. This does not reflect an intrinsic bias to white within the game, but rather the number of pieces black has to deal with compared to white. After 3 or 4 games a beginner should become reasonably proficient as black and start to be able to play black to the same level as white. Stalemates may appear to be more frequent than they are when learning to play the game, but black can usually move to release more pieces, or change a vital stack causing the apparent stalemate. In these circumstances, black will usually win shortly afterwards. So players should bare in mind that stalemates are actually very rare.

Remember: Any combination of pieces can make up a stack, and if black makes a stack of six then white still wins. If white immobilizes black then white wins. A player can never enter a piece directly onto the top of a stack or onto the central circle. They may only enter pieces onto an EMPTY circle which is not the central one. The central circle can only be moved into.

Tactics for White: Try to keep the white pieces mobile, and as high up a stack as possible. Try to build a high stack capped with white safe pieces, on the central circle. Try to build and make good use of zebra (alternating colors) stacks, as all the white pieces can still be thought of as mobile. White has an advantage early on in the game, so try to gain a good position for the later part of the game.

Tactics for Black: Try to bring on the black pieces as soon as possible, as the more pieces that black has in play the better. Try to avoid the central circle, as white can use pieces there to its advantage, but make sure that white doesn't gain advantage of the center. Try to avoid stacks of five, unless part of a your strategy. Try to make all the black pieces safe. Try to build wells - high stacks surrounding an empty or low stack, from which a piece once inside cannot get out. Bare in mind that a piece just moved by a player cannot be moved by the opponent until the next turn, as good use can be made of this in the later part of the game. Take note that if white only has a single piece left which they can move, then black will never be able to move that piece, and should think about releasing additional pieces for white to use, as this will usually make it more difficult for white to win.

An example

The 3 white stone stack is permanently safe since it is over a red dot cell. The left stack is just temporarily safe (either player can put stones on top of it).

The top black stone of the central cell, can move to any cell (it has size 2, and the others are empty or have stacks of size 3 or 1). The single black stone (stack of size 1) cannot move to the adjacent stack of size 3.