The only game application bundled with Mac OS X is Chess (path: /Applications/Chess), a full-featured chess game that includes support for speech recognition. The Chess interface, shown in Figure 3.11, is simply beautiful.
In all honesty, the underlying chess engine isn't Apple's, but that of GNUChess, a free chess application available for the UNIX platform since the mid-1980s.
Figure 3.11 Chess is a GUI front end to GNUChess.
When Chess starts, it displays a new board ready for play. Move a piece by dragging it from its original position to the location you want. If a move is invalid, Mac OS X plays the system beep, refuses the move, and displays a message in the window's title bar.
To control the game's difficulty or to change to a computer-computer or human-human game, open the Chess Preferences dialog box. Use Chess's preferences to control how difficult the game will be, who is playing, and whether speech recognition should be used.
If you're using speech recognition, be aware that Chess recognizes only a few patterns to control your pieces:
<Piece> <Square> to/takes <Square>
Take back move
For example, pawn b2 to b4 is a valid opening move.
Finally, if you've selected the Computer vs. Computer option in the Chess Preferences dialog box, the game won't start until you click the Start Computer Vs. Computer Game button in the Controls dialog box, which is accessed via the Game menu.
You can access a few additional preferences by choosing the Controls option from the Game menu. In the Controls dialog box, each player is represented by a chess piece, as shown in Figure 3.12. Beneath each player's settings is a white progress bar. When the computer is thinking about a move, the bar fills in from left to right to indicate how close the computer is to making a move. To force the computer to move before it has finished thinking, click the Force Computer To Move button.
Clicking the color well to the right of the player name launches the system Colors panel where you can choose a new color for each player's pieces. The color is not applied until you click the Set Piece Colors button. Keep in mind, however, that the game still makes references to the pieces using their original colors.
The Move menu is used to ask for a hint and to replay or take back the last move. In a sense, the Move menu lets you cheat.
Use the View menu to toggle between a grayscale two-dimensional representation of the board (Shift+Command+A) and the default 3D board (Shift+Command+B).
Figure 3.12 Use the Controls dialog box to set some additional game preferences.