If a player having the move touches one of his pieces he is under
compulsion to move it; if he touches a hostile piece he must
capture it, provided that the piece can be properly moved or
captured in either case. This rule is of no effect if the piece
so touched cannot be moved or captured, as the case may be.  So
long as the hand has not left the piece to be moved, the latter
can be placed on any accessible square. If a player touches a
piece with the sole object of adjusting its position, he must
apprise his opponent of his intention by saying  "J'adoube"
beforehand. It is best to move the King first when castling. If
the Rook is moved first, and unless the King is played almost
simultaneously, a doubt might arise whether castling or a Rook's
move only was intended.

If a player has castled illegally, Rook and King must be moved
back, and the King must make another move, if there is a legal
one. If not, any other move can be played. A player who makes an
illegal move with a piece must retract that move, and make
another one if possible with the same piece. If the mistake is
only noticed later on, the game should be restarted from the
position in which the error occurred.


II. NOTATION


A special notation has been adopted to make the study of games
and positions possible, and it is necessary for students of the
game to become thoroughly conversant with it. The original and
earliest notation is still in use in English, French, and Spanish
speaking countries. It is derived from the original position in
the game, in that the squares take the names of the pieces which
occupy them. Thus the corner squares are called R 1 (Rook's
square or Rook's first), and to distinguish them from one another
QR1 or KR 1 (Queen's or King's Rook's square). The squares
immediately in front are called QR2 or KR2. A distinction is made
between White and Black, and White's R 1 is Black's R 8, Black's
R 2 is White's R 7, White's K B 3 is Black's KB6, and so on. K
stands for King; Q for Queen; B for Bishop; Kt for Knight; R for
Rook; and P for Pawn. In describing a capture, only the capturing
and the captured pieces are mentioned, and not the squares.

When confusion is possible, it is customary to add whether King's
side or Queen's side pieces are concerned, e.g. KRx Q Kt.  In
this notation it is necessary to bear in mind which Kt is the Q
Kt, which R is the KR. This becomes increasingly difficult as the
game goes on and pieces change their places.  Many sets of
chessmen have one Rook and one Knight stamped with a special
sign, to show they are King's side pieces. This is not necessary
in the case of Bishops: a white KBis always on white squares, a
white QBon black squares.

A more modern notation is the algebraic notation, which has been
adopted in most countries. It has the advantage of being
unmistakably clear, and also more concise. Here the perpendicular
lines of squares (called files) are named with the letters a-h,
from left to right, always from the point of view of White, and
the horizontal lines of squares (called ranks) with numbers 1-8
as before, only with the distinction that the rank on which the
White pieces stand is always called the first; thus the square we
named White's QB2 or Black's QB7 is now called c2 in both cases.
Black's QB2 (White's QB7) is always c7. In capturing, the square
on which the capture takes place and not the piece captured is
noted, for the sake of uniformity. In the case of pawn moves, the
squares only are noted.