Othello

To run:

npm install

node othello.js

To play: Enter the coordinates of the piece you want to place, e.g. a1 or h8.

Rules

• Play happens on an 8x8 grid. Game pieces are discs with a black side and a white side. The face-up side of a piece indicates its current owner.
• The game begins with two black pieces and two white pieces, as shown:

*   a b c d e f g h
1
2
3
4        B W
5        W B
6
7
8

• Players alternate turns, beginning with black.
• A player's turn consists of placing a new piece of their color on an empty space and then flipping the opponent's pieces.
• A player flips lines of one or more opposing pieces when they are bookended (surrounded) by the newly placed piece and one of their existing pieces. The line including the bookends must be contiguous (no gaps). Lines of flipped pieces can be othogonal or diagonal. Multiple lines may be flipped in a single turn. (Note: One of the two surrounding pieces MUST be the newly placed piece.)
• For example, in the following game, black plays g6. This move flips the white pieces at c6, d6, e6, f5, and f6 to black.

*   a b c d e f g h       a b c d e f g h       a b c d e f g h
1                     1                     1
2                     2                     2
3       W B W         3       W B W         3       W B W
4     W B B W B       4     W B B W B       4     W B B W B
5   W B W B W         5   W B W B *         5   W B W B B
6   B W W W W         6   B * * * * B       6   B B B B B B
7                     7                     7
8                     8                     8

• Every move must flip at least one piece. If a player cannot move, their turn is skipped.
• For example, in the following game, white has no legal move:

*   a b c d e f g h
1       W W W   W
2     W W W W   W
3   W W W B W W W
4     W B B W B W
5 W W W W W W B W
6   W W W W W W W
7     W W W W W W
8 B B B B B B B W

• When neither player can move, the game ends.
• At the end of the game, the player with the most pieces wins. If players have the same number of pieces, the game is a tie.

Notes:

• You can change the size of the board by editing the following line in othello.js: static SIZE = 8; The maximum size is 26.

AI

• You can let the machine play for your by entering a "-" (dash) insead of coordinates.
• You can let the machine play itself by entering "autopilot" instead of coordinates.

Multiplayer

• Experimental feature.
• To start a multiplayer game type "multi"