The board is 12 by 12 with an additional squares on each corner extending the main diagonals. The outer zone consists of the remaining 84 squares around the edge of the board which are more then 2 squares away from the center. On the other hand, while she can attack the king's square from the mid-zone, she can't attack outer squares on the opposite side of the board. By-eMail Server . As a main stream chess variant, B.O. Chess gets most of its rules from standard chess.
All rules concerning draws, perpetual check, etc. apply.
Piece Movement Pawns may move up to 4 squares on their first move. After the first move a pawn may always move forward one or two squares except when moving to the last rank. A pawn may only move to the last rank by moving forward one square. A pawn reaching the last rank promotes to any piece except king or pawn. Thus it takes at least five moves for a pawn to promote.