PHAGE: A Two Player Strategy Board Game

2007-04-06T10:43:00.001-07:00

Back in 2003, I developed a two player strategy board game called ‘Phage’, which has recently been implemented in Cocoa by Stig Brautaset. It is available to download for OS X from his web site. It is the sort of game that would probably appeal to anyone who enjoys playing Chess or Draughts.

PHAGE - Game Rules

Summary and Objective

Phage is an abstract strategy game played by 2 players on an 8 x 8 game board.

The object of the game is to manoeuvre your pieces in such a way as to limit your opponent’s ability to move. The game is over when one player is unable to make a legal move. Draws are possible.

There is a maximum of 56 legal moves per game – 28 per player. Each game typically lasts between 5 and 10 minutes.

Game Board

The diagram below shows the position of the playing pieces at the start of a game. Although the image quality is not particularly good, you can print it out and play the game using two different coloured pens.

The two grids on either side of the game board enable players to record the number of moves made by each of their playing pieces. The starting positions, which represent the first of eight permissible positions, have already been registered.

Playing Pieces and Movement

Players control 4 playing pieces; each have different properties.

The Circle can move either horizontally, vertically or diagonally. It can move both forwards and backwards. The Square can only move diagonally. It can move both forwards and backwards. The Triangle can move both horizontally and vertically. It can only move forwards. The Diamond can move both horizontally or vertically. It can move both forwards and backwards.

Each piece is permitted to occupy a maximum of 8 unique positions during the course of the game. However, the first position is predetermined at the start, so in practice, each piece has a maximum of 7 moves. Moves are not transferable between pieces (i.e. if one piece is blocked in and has only used 4 moves, it cannot transfer its remaining 3 moves to another piece).

There is no capturing and no pieces are removed from the board during the course of the game. When a playing piece is moved, the square from which it moved becomes a ‘closed square’ and is marked accordingly. The square can no longer be passed through or landed upon by either player for the remainder of the game. An ‘open square’ is one that is either unoccupied or else has not been occupied at any point during the course of the current game.

Gameplay

White moves first. The following six diagrams show the first six moves (three each per player) of a game to illustrate how these rules apply.

Move 1 – White: e3-h6

Player One moves the Square piece from e3 to h6. The threat is h6 to f8, potentially followed by f8 to g7, which would limit Black’s Diamond on h8 to a maximum of just 1 of its possible 7 remaining moves.

After completing the move, e3 is designated a ‘closed square’ and is marked. The move is also recorded against the corresponding playing piece in Player One’s grid to the right of the game board. The Square piece now has a maximum of 6 moves left in this game.

Note: When playing this game with paper and pens, I have found it easier to use an ‘x’ to represent the Square and a ‘+’ sign to represent the Diamond – the idea being that a piece can move in the same direction as its ‘spokes’.

Move 1 – Black: h8-d8

Move 2 – White: g4-d7

Move 2 – Black: d6-a3

Move 3 – White: a1-f1

Move 3 – Black: d8-c8

As this sequence shows, the number of ‘open’ squares diminishes with each move, and it becomes progressively more difficult to manoeuvre the pieces.

ABSTRAGA

PHAGE: A Two Player Strategy Board Game