Mathematical_Recreations-Kraitchik-2e

288 Mathematical Recreations
tions of the odd-numbered rows and columns. For ease of
reference we shall assume the cells numbered as in Figure 156.
Although at first there is not more than one piece on a cell,
as the game proceeds several pieces may be stacked on one
another, forming what are called
columns. It will be convenient
to refer to the set of pieces on a
single cell as a column in every
case, even though a particular
column may consist of hut one
piece. The topmost piece of a
column is its guide, and it is the
guide that determines the move­
FIGURE 156. Lasca Board. ment of the column. It is in this
that the principal ingenuity of
the game consists. For, as we shall see, a column usually
contains pieces from both sides in the game, and the guide
is constantly changing, so that a column belongs first to one
side and then to the other.
There are 22 pieces, 11 to a side. Those of one side are
white, and of the other black. (We shall refer to each player
by the color of his pieces.) The pieces are fiat, to permit
stacking. One face of each piece is plain, and the other is
marked. When the plain face is up the piece is called a soldier.
When the marked face is up the piece is called an officer.
At the start of the game White's 11 soldiers are placed on
cells 1 to 11 and Black's on cells 15 to 25. Hence at first each
column has only one member - its guide. White and Black
play alternately, White beginning. The manner of executing
the moves is described in the next two paragraphs.
Moving without Capturing. A column guided by a soldier
may move forward one step along either diagonal to an unoccupied
cell. When a column guided by a soldier reaches
his seventh row (cells 22-25 if the soldier is White, 1-4