RULES.txt

Stack Wars is an abstract board game played on a two dimensional grid, similar
to a Chess or Go board. The game is currently still being play tested / 
balanced, but the rules below should give you enough to try it out on your own.

== Board layout + setup

The board represents a battlefield that two players must
fight for control over, with the goal of invading each other's bases. The ASCII
representation below shows a standard 9x9 grid representing the battlefield.

       0      1      2      3      4      5      6      7      8
     WWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWWW
  0  (___)--(___)--(___)--(___)--(___)--(___)--(___)--(___)--(___)
       |      |      |      |      |      |      |      |      |
  1  (___)--(___)--(___)--(___)--(___)--(___)--(___)--(___)--(___)
       |      |      |      |      |      |      |      |      |
  2  (___)--(___)--(___)--(___)--(___)--(___)--(___)--(___)--(___)
       |      |      |      |      |      |      |      |      |
  3  (___)--(___)--(___)--(___)--(___)--(___)--(___)--(___)--(___)
       |      |      |      |      |      |      |      |      |
  4  (___)--(___)--(___)--(___)--(___)--(___)--(___)--(___)--(___)
       |      |      |      |      |      |      |      |      |
  5  (___)--(___)--(___)--(___)--(___)--(___)--(___)--(___)--(___)
       |      |      |      |      |      |      |      |      |
  6  (___)--(___)--(___)--(___)--(___)--(___)--(___)--(___)--(___)
       |      |      |      |      |      |      |      |      |
  7  (___)--(___)--(___)--(___)--(___)--(___)--(___)--(___)--(___)
       |      |      |      |      |      |      |      |      |
  8  (___)--(___)--(___)--(___)--(___)--(___)--(___)--(___)--(___)
     BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB

The battlefield starts off empty (as shown above), with each player holding a
number of armies in reserve equal to three times the width of the battlefield.
For example, on a 9x9 grid, each player starts off with 27 armies, on a 13x13
each player starts off with 39 armies, and so on.

== Possible turn actions 

Black starts the game, and then play alternates as each player takes one of the
following actions per turn.

  - FORTIFY a CONTROLLED territory by adding a single army from reserves
  - MOVE a single army from a CONTROLLED territory to an adjacent
    UNCLAIMED territory
  - ATTACK a single enemy territory adjacent to one of the player's 
    CONTROLLED territories
  - INVADE the enemy base (may be a MOVE or ATTACK, details explained later)

Throughout the game, the following territories are considered to be CONTROLLED
by the active player:

  1) Anything that lies on the BASELINE (i.e. boundary line between the 
     battlefield and the player's base). This works out to any territory 
     in row 0 for white, and any territory in row N for black, where N is
     the last row of the board.

  2) Any territory which has at least one of the active player's army fortified
     within it.

Some restrictions apply to how turns play out, depending on game conditions:

  * In order to FORTIFY a position, the active player must have at least one
    army in reserves.

  * Adjacent territories are a single edge away horizontally or vertically,
    but not diagonally. E.g. adjacent territories to (2,2) are:
    (2,1), (2,3), (1,2), (3,2). You cannot MOVE, ATTACK, or INVADE diagonally
    at any point in time.

  * Two or more armies within a single territory form a STACK. If moving from
    a STACK to another position, only a single army is moved, not the 
    entire STACK.

  * You can only carry out an ATTACK from a territory which does not contain
    a STACK (i.e. a position with a single army)

  * If an ATTACK on an enemy territory causes that territory to becomes 
    unoccupied, you must immediately move the army you attacked with 
    into that territory.

  * Whenever an army is removed from the battlefield via an ATTACK, 
    it is immediately removed from play, and does not count for or against
    either player's score, nor does it get returned to the either player's
    reserves.

== Gaining Points

An INVASION is carried out by moving one of the active player's armies into an
adjacent territory which is part of the enemy's BASELINE. This can be done via a
MOVE or an ATTACK. As soon as the active player's army is moved onto the
baseline, it is removed from play, and the active player gets one point added to
their score.

== Ending the game

At the exact moment that one player has no armies in play as well as no armies
in reserve, the game immediately ends. If one player has more points than the
other, the player with the greater amount of points win. If instead each player 
has an equal number of points, the game ends in a draw.

Alteratively, both players have the option of resigning at any time. Because
this is a game in which it may be obvious who the winner is well ahead of the
standard end game conditions, it should not be considered impolite to resign
when the battle is no longer interesting.

== Questions / Suggestions?

Email gregory.t.brown@gmail.com

== Implementation

You can find the source code for this game at:
http://github.com/sandal/stack_wars