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Throngs a highly abstracted wargame (territorial invasion game) for two players. It is typically played on the intersections of a triangular grid, using Go stones. It is a double-move game: each player takes 2 full turns in succession before the next player takes control.

Movement: The game is distinguished by the way the power of a moving piece is determined according to the pieces around it: A piece can move as far as the difference in count of the friends and enemies in its immediate vicinity.

Removing an enemy and adding one's own piece take one power unit each. Remaining power goes into a series of steps or hops that may change direction at empty locations.

Strategy: Power to travel up to seven units per move can be developed during the game. As the offensive capacity develops, defensive measures are needed, first starting with limiting the mobility of enemy stones by approaching them, then by building walls, and thickening them along the axes of the opponent's catapulting sites (empty locations surrounded by many of that player's own stones.) These sites allow adding a stone and catapulting it up to a distance of 5, and are re-useable. In addition to these methods, defense is by scattering stones behind one's own lines to immobilise enemy stones that invade.

The majority of turns naturally involve placement as well as movement, due to the benefit of gaining material; even though newly placed stones travel a reduced distance due to the cost of their placement. Occasional moves without placement are used mainly to initiate difficult invasions, as they risk simultaneously opening up positional weaknesses.

Individual stones may be captured by replacement when they are sufficiently out-numbered at a location, which means that towards the end of the game, chains of stones not anchored to a triangle, loop, or board edge will be consumed one-by-one by captures. Thus the shape and nature of territorial walls is worth contesting.

Boards: The standard board is centerless, designed to allow maximal distance moves from the center, while minimizing the size of the board. The hexagonal corner regions help to stabilize invasions in outlying areas. The reverse angles along the edge are slightly less defensible than the other parts, breaking the edges into stategic zones.

The game is easily adapted not only to to different size and shape boards, but also to different grid topologies, while remaining interesting and playable. A 'perforated' grid is included to demonstrate this, but there are many other possibilities as well.

The center of the board is very advantageous, and a pie rule or balanced starting positions are needed. The standard starting position places the initial pieces near the edges to allow players a wider variety of strategies. Placing multiple starting stones, and or playing on torus boards, leads to finer grained, denser, highly tactical games, while using few starting pieces and larger boards or boards with less connectivity (e.g. boards with holes, and boards on semi-regular grids) lead to a more territorial game.

Play on a torus also eliminates the advantage of a board center, but requires a larger board because invasion is no longer from a single direction.


Each player tries to achieve a majority of pieces when the board is full and no captures are left to be made.

- The vicinity of a site is that site together with all the sites immediately adjacent to it.
- The action-potential of a site is the number of the moving player�s stones in the site�s vicinity minus the number of the opponent�s stones there. For example, the action-potential of a site on Black's move is 3 if its vicinity contains either: 5 Black and 2 White, 4 Black and 1 White, or 3 Black and no White.

The structure of the game:
Before play begins, one player places a Black stone and two White stones on three different junctions. Then the other player decides to play either as Black or as White. After this the players alternate turns taking two moves each, beginning with Black.

A standard setup is also provided. You may choose the standard opening position, or use the Pie option to set your own.

A move begins on a site that has sufficient action-potential (calculated as described above). Before movement, the following deductions must be made from the potential, based on the junction's contents:

-- If the junction is occupied by the enemy, you MUST deduct 2 actions to remove it and replace it with your stone.
-- If the junction is empty, you MUST deduct one action to add one of your own stones, with the following exception:
---- This empty-junction deduction is waived if there is no other empty junction next to the chosen junction and the action-potential at that junction is zero.
-- No deduction is taken if the junction is already occupied by your own stone.

When you select a site, the application will calculate these deductions for you, and if there is any remaining action potential, it will be shown on the transparent stone.

If you have any leftover actions, you MAY now move the stone at that siten; in a sequence of steps and jumps, spending one action for each space moved during the sequence.
-- A step is a move to an adjacent empty junction.
-- A jump is a movement in a straight line over occupied spaces.
The distance along the path traveled may not exceed the number of actions that remain.

The application accepts a click on the final destination of the stone. It calculates whether the destination can be reached according to the rules. if you click on an intermediate site, the move will end there.

Voluntary passing and partial passing are allowed, with the following exception:
-- A piece must be added during the first move of a turn that follows a fully-passed turn.

Ending the game:
Play continues until both players pass, and the player with the most pieces on the board wins.
Resigning in advance is a courtesy. However the AI is not designed to resign.


Dale W. Walton

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