Dewdney's original game, Alak, is different from the one described in Alak. Here are the original rules, according to an article by Sean Burke in ''The Perl Journal'', (18).
Very important footnote from said article: "Actually, I'm describing only my interpetation of the rules Dewdney describes in Planiverse. Many other interpretations are possible." As always, truth-seekers should return to the source. -- Scartol
Alak is a two-player game played on a one-dimensional board with eleven slots on it. Each slot can hold at most one piece at a time. There's two kinds of pieces, which I represent here as x and o - x's belong to a player called X, and o's to the player called O.
The initial configuration of the board is:
For sake of the article, the slots are numbered from 1 (on the left) to 11 (on the right), and X always has the first move.
The players take turns moving. At each turn, each player can move only one piece, once. (This is unlike checkers, where you move one piece at a time, but get to keep moving if you jump over your opponent's piece.) A player cannot give up his turn. A player can move any one of his pieces to the next unoccupied slot to its right or left, which may involve jumping over occupied slots. A player cannot move a piece off the side of the board.
If a move creates a pattern where the opponent's pieces are surrounded, on both sides, by two pieces of the mover's color (with no intervening unoccupied blank slot), then those surrounded pieces are removed from the board.
The goal of the game is to remove all of your opponent's pieces, at which point the game ends. Removing all pieces but one ends the game as well, since the opponent can't surround you with one piece, and so will always lose within a few moves anyway.