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65 Square Chess

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During my last hiatus from this site, (zzo38) A. Black posed some good questions in the comments section. I felt the need to revise the whole variant slightly in order to clarify and answer these questions.


Referring below to 65 Square Chess:

This is Western Ortho-chess but please pretend that there is another square located in the very center of the game, accessible only diagonally via e4, d4 or d5, e5:

* * * *     * * * * 
*     *     *     * 
* d5  *     *  e5 * 
*     *     *     * 
* * * * * * * * * * 
      *     * 
      * Z5  * 
      *     * 
      * * * * 
* * * *     * * * *
*     *     *     * 
*  d4 *     *  e4 * 
*     *     *     * 
* * * *     * * * * 

The square - represented here by Z 5 - is like a square from another dimension strangely situated in the middle of the board.

One can only enter into the Z5 Square from one of the four center squares (d4, e4, d5 or e5). Since the only entry points are diagonally located, the rook could never be on Z5. (Except in the case of 65 Square 2014 Rook X). One can also exit through the d4, e4, d5 and e5 squares.

If a pawn should enter Z5, it is given a one time only ability to make a non-capturing diagonal move.

Knights or knight-compounds shall be allowed to enter Z5 via the Mao route and exit via the Moa route.

Also: In the case of 65 Square Chess 2014, there are four more exit-only portals, between h4 and h5 and between b4 and b5. So, strictly as an exit square, Z5 can be thought to simultaneously exist in between those flanking areas - but only for the purpose of exiting vertically (up or down but only "up" for pawns of course) from the center of the board.

* * * *        * * * *
*     *        *     *
* b5  *        * h5  *
*     *        *     *
* * * *        * * * *
*     *        *     *
* Z5  *        * Z5  *
*     *        *     *
* * * *        * * * *
*     *        *     *
* b4  *        * h4  *
*     *        *     *
* * * *        * * * *   

In the case of 65 Square Chess 2014 Rook X, the Rook is the only piece that can enter Z5 via h4, h5, b4 or b5.


Updated version, updated pieces: The Rook-Ferz, Knight-Guard, Cardinal and Aanca have replaced the more typical pieces. The first idea was to give the Rook an ability to enter into Z5 diagonally. The second idea was to give all the other pieces a value very roughly equivalent to that of the newly minted Rook-Ferz, since it's not a CDA. Since these pieces are so similar in value, a win of "the exchange" shall be difficult if not impossible for players to determine.


Castling, pawn promotion and other rules are O.Q.E.D. - as you'd expect in a typical old-fashioned / orthodox western-style chess variant of which this is one.

There are now six different versions of this game - links to older ones lacking the flank portals are in the notes.

The difference in the 2014 versions include the extra portal squares on the h and b files described in the Setup section.

65 Square Chess 2014

65 Square Chess 2014 Orthodox Western

65 Square Chess 2014 Rook X


How often will the outcome of the game be decided by the player who can successfully occupy the mysterious 65th square?

Please note: In this variant, white can occupy e4 and d4 while black occupies d5 and e5 and no pawn will be able to capture any of the other two because an empty square - Z5 - intercedes!

In this variant, the center counter gambit 1. e4 d5 can not result in 2. ed because there is a square in between e4 and d5.

Previous versions of the game:

Click here to play: 65 Square Chess

65 Square Chess with Berolina Pawns

65 Square Chess with Ferzes - Recommended that Ferzes promote like regular pawns.

Thanks to (zzo38) A. Black for asking critical questions leading to some important clarifications and special rules.

Thanks to Dan Troyka for the suggestion of how to represent the 65th square in this game and for suggesting an orthogonal aspect to the 65th square's interaction with the regular squares.

This 'user submitted' page is a collaboration between the posting user and the Chess Variant Pages. Registered contributors to the Chess Variant Pages have the ability to post their own works, subject to review and editing by the Chess Variant Pages Editorial Staff.

By Jeremy Gabriel Good.
Web page created: 2006-12-22. Web page last updated: 2014-12-22