Editing Cylinder chess (section)

== Rules and gameplay ==
{{Chess diagram
 | tright
 | 
 |  |xx|  |xx|  |  |  |  
 |xx|  |  |  |xx|  |  |  
 |  |  |  |  |  |xx|  |xx
 |  |  |  |  |  |  |xx|  
 |xo|  |  |  |  |xx|xo|xx
 |xx|xo|  |  |xx|xo|  |  
 |  |xx|  |xx|  |  |  |nd
 |  |xo|bl|  |  |xo|  |  
 |The diagram shows possible moves of a bishop on c1 and a knight on h2 on a cylindrical board. The bishop cannot move through the board's upper and lower sides.
}}
The game is played as if the left and right sides of the board are connected.  When a [[Chess piece|piece]] goes off one edge of the board, it reappears from the other edge.<ref>D.B. Pritchard (1994). ''The Encyclopedia of Chess Variants'' (p. 79). {{ISBN|0-9524142-0-1}}.</ref> For example, it is legal to move a rook from a3 to h3, even if there is a piece on b3, since the rook can move left from a3; a bishop on c1 can move to h4 by going from c1 to a3, and then going up and left from a3 to h4; if White has a pawn on a5, Black has a pawn on h7 and Black plays 1...h7–h5, White can capture the black pawn ''[[en passant]]'' with 2.axh6; and so on.

[[Castling]] can be handled in one of three ways:
* Castling is allowed, but not with a rook over the board edge. This maintains the options for castling available in standard chess.
* Castling is not allowed. Proponents of this convention argue that cylinder chess nullifies the purpose of castling, as all files are equally dangerous on a cylindrical board.
* In addition to normal castling, castling with a rook over the board edge is also allowed. This is done by moving the king two squares toward the rook and moving the rook to the square that the king passed over (in the same manner as usual).

One possible rule variation in cylinder chess is to allow ''null moves'', or moves such that every piece stays in the same place, as long as any piece performing such a move travels a nonzero distance by crossing over the edge of the board; only a rook or queen can perform such a move. This variation is rare in actual play, but it is often seen in cylinder chess problems.<ref>[http://www.chessvariants.org/problems.dir/prcylin2.html From A. W. Mongredien, Bulletin de la FFE, No. 19, 1926]</ref>
{{clear}}