You can invite someone to play a match by selecting their name in the Players window and choosing “Invite…” from the Player menu. Double clicking a name is a convenient shortcut. This brings up a dialog where you can choose the number of points for the match, or select whether to resume a saved match.

Once a match begins, the board window will display the initial state with the dice showing for the opening player.

Please roll or double
A small floating window appears when it is your turn to roll or double. The window contains two buttons, which you can click. You can also use commands under the Game menu to roll (Cmd-R) or double (Cmd-D) even when the floating window isn’t showing.

You can position the floating window in a convenient place on your screen. It will reappear there each time it’s your turn to roll or double.

Moving checkers
When it’s your turn to move, there are two ways to move your checkers:

• Drag and drop your checkers.

• Click checkers with the Option or Command key pressed. 

Dragging and dropping your checkers mimics the way you move checkers on a real backgammon board. MacFIBS will not let you make an obvious error (for example, moving six places when your dice are 1-3), but it is not completely idiot proof. You will get a reassuring “thunk” sound if your move is accepted by MacFIBS.

You can also click a checker while pressing either the Option or Command keys. MacFIBS will automatically move the checker using the following logic:

• If the Option key is pressed, try to move the checker by the left dice value. If that point is blocked, or the left dice has already been used for a prior move, try to move the checker by the right dice value.

• If the Command key is pressed, try to move the checker by the right dice value. If that point is blocked, or the right dice has already been used for a prior move, try to move the checker by the left dice value.

Sending your move
Nothing is sent to FIBS while you are moving checkers. When you’ve taken your two moves (or one, three, or four moves depending on the circumstances), click either of your dice on the board. If Sound is enabled, you will hear your dice being picked up from the board.

The dice remain on the board until confirmation is received back from FIBS that the roll was accepted. You can see the move command and response from FIBS in the Terminal window.

Correcting an error in moving
When you click the dice, you have committed that move; it’s too late to change your mind!

Before you send your move, if you make a mistake in moving or simply wish to make a different move, you can take back a move using the Undo (Cmd-Z) command. You can also refresh the board (Cmd-B) to reset it to its initial position before you started moving.