Chess Variants/Balbo's Game

Introduction
Balbo's Game uses a special cross-shaped board made up of 70 squares, and each player commands a full chess army minus one pawn.

History
Balbo's Game was created by its namesake, Monsieur G. Balbo, in 1974. It subsequently appeared in a French chess magazine, Le Courrier des Echecs, in September of that year.

Rules
All of the standard rules of chess apply. However, because the king starts on a different rank from the rooks, this variant has no castling.

In addition, the promotion rules have been tweaked to accommodate the new geometry:


 * A pawn that reaches the square at the far ends of the d- through h-files may promote to a queen, rook, bishop or knight as normal.
 * A pawn that reaches the square at the far ends of the c- or i-files may only promote to a bishop or a knight.
 * A pawn that reaches the square at the far ends of the a-, b-, j- or k-files may not promote at all. It will simply sit there as an obstacle until it is captured or it manages to make a capture that takes it off those files, at which point it may promote.

Sub-variants
This chess variant does not not have any notable sub-variants.