Gammonx. (Amiga Resource) (evaluation)
by Steve Tibbett, Brad Schenck

Note from the Editors: GammonX is an Amiga version of the classic board game backgammon. For its five levels of computer opponents and its stunning graphics, GammonX received third place in the Amiga Resource $10,000 programming contest.

Getting Started

To run the program, double-click on the GammonX icon, which can be found in the GammonX drawer on this issue's companion disk. GammonX will display a series of credits windows. Click on each window to make it go away. GammonX may also be started from the CLI. Be sure to change directories (CD) to the GammonX directory so that the program can find its graphics file (GammonX-.Dat). GammonX is fully multitasking so that you can play while you work. Press Left Amiga-N to get to the Workbench screen and Left Amiga-M, to get back to GammonX.

You set up and start the game using the program's menus. The GammonX menu has three selections: New Game, About, and Quit. New Game starts a game, About displays the first credits window, and Quit exits the game. The other two menus let you choose the players. The player controlling either side can be human or one of five types of computer player. So you can play human against human, computer against human, or computer against computer.

To start the game, set up the light and dark players as you wish and then select New Game. The computer will roll the dice. In GammonX, the player controlling the dark pieces moves first. You can always tell whose turn it is by looking at the turn indicator (a white or brown backgammon piece) at the top left corner of the screen.

There are three gadgets on the right side of the screen. Quit immediately exits GammonX. Pass allows you to give up your turn when you cannot make a move. Roll forces the computer to move your pieces, which is handy for beginners who are just learning to play the game.

In GammonX, the computer rolls the dice. To move a piece, you move the mouse pointer over it and press the left mouse button. While holding down the button, drag the piece to its destination. Then release the button.

How to Play

Backgammon's rules are fairly simple. The backgammon board is divided vertically by a bar. The lower left quadrant is the home table of the dark side. The upper left quadrant is the home table of the light side. Each player has 15 pieces (called men), which start the game on four triangles (called points). The dark men move from left to right across the top of the table, then right to left across the bottom of the table. The light men move from left to right across the bottom of the table, then from right to left across the top of the table.

In GammonX, the dark player moves first. During your move, you choose one of your men and move it along the points according to the value of one of the dice. Then you choose another man (or the same one) and move it according to the value of the other die. In the case of doubles, each die is used twice. For example, a pair of 6s means that four men can be moved 6 points each, two men may move 12 points, two men can move 6 and one man can move 12, and so on.

You can't make a move if it means your man will land on a point occupied by two or more opposing men. If your man is placed on a point containing a single opposing man, the opposing man is sent onto the bar.

If you have a piece on the bar, you can't move until that piece has been taken off the bar. You can take your man off the bar if you roll a number which specifies a point in your opponent's home table that doesn't have two or more opposing men. For example, if you have one piece on the bar and you roll a 1 and a 2, you can place the piece on the table on the leftmost point of your opponent's home table or on the point next to it, assuming that one of those points has fewer than two opposing men already sitting on it.

When you've moved all of your men into your home table, you can begin to bear off. Bearing off is the procedure of removing pieces from the board. The ultimate goal of the game is to bear off all of your pieces. You bear off men according to the dice you roll. For example, if you roll a 3 and a 5, you can pull one piece off the third point from the left and one from the fifth point from the left. If a die indicates a point that's unoccupied, you bear a piece off of the highest point below that value.

GammonX makes it easy to learn how to play backgammon. It doesn't let you make illegal moves, and if you get stuck, you can click on Roll to make GammonX move your pieces for you.

There's a lot of strategy to backgammon. To learn more about the game's rules and its strategies, read According to Hoyle by Richard L. Frey (Fawcett Crest Books).