Copyright (c) 1990 Sid Sackson 

This game is played on the following 7x8 board (with two additional cells):

TOWER - A stack of two stones of either color. The color of the top stone determines ownership.
TURN - On each turn, each player can move up to five times, if it satisfies the following conditions:
If there is no tower on the board, move one of his stones to an (orthogonal or diagonal) adjacent empty cell and his move ends, or to an occupied cell which builds a tower. If there is already a tower on board, the player should use that one.
If this first move was done, and the built tower belongs to the player, then the player may continue moving. Otherwise, the player must pass.
Move the tower to any orthogonal or diagonal direction, placing the bottom stone on the first cell, and the top stone on the next cell in that chosen direction. 
The stones are place over some stones already there.
A move creating two towers is invalid.
If a player builds another friendly tower he may repeat this step, at a maximum of 5 moves (including the eventual tower building).
On the last possible move, the player cannot build a friendly tower.
If a player builds an enemy tower or does not build a tower, he must pass.
If the player scores, the turn ends (check about scoring below).
SCORE - If a player moves a stone behind the opponent's first row, he scores one point. If the player moves a stone to the marked cell behind that setup area, it scores 2 points.
The scoring stone is then moved to one of the cell in the first row of its setup area. If the row is occupied, place it on the 2nd row. If that is occupied, place it in the 3rd. And if that is still occupied, place it on any empty cell on the player's half board. This movement does not count as a move turn.
If the player cannot make any valid move, he loses 2 points. If there is a tower on the board, the bottom stone is placed on its setup area by its owner.
GOAL - The player that first reaches the number of agreed points, wins.

Usually this number of points to win go from 12 to 24. Different values for each player can be used as handicaps.

An example

White must move the tower but he has some moving options.

He can move down, left or right, passing the turn (no more towers created).

He can move move forward-right, creating a new white tower, so he can move again.

He can move up, but it would create a black tower, so he would pass his turn.

However, he cannot move to the forward-left because then it would create two towers, which is invalid.