numbers are \e{not} covered by a single domino. Right-clicking again
removes the line.
+You can also use the cursor keys to move a cursor around the grid.
+When the cursor is half way between two adjacent numbers, pressing
+the return key will place a domino covering those numbers, or
+pressing the space bar will lay a line between the two squares.
+Repeating either action removes the domino or line.
+
(All the actions described in \k{common-actions} are also available.)
\H{dominosa-parameters} \I{parameters, for Dominosa}Dominosa parameters
\cfg{winhelp-topic}{games.blackbox}
A number of balls are hidden in a rectangular arena. You have to
-deduce the positions of the balls by firing from lasers positioned at
+deduce the positions of the balls by firing lasers positioned at
the edges of the arena and observing how their beams are deflected.
Beams will travel straight from their origin until they hit the