40. Perpetually offering to exchange or to sacrifice is a draw.
(See examples in Diagram 101 through 104)
Diagram 101: Red (in Capital) moves first
Red keeps trying to exchange or sacrifice the Rook. Since the Black
Rook is free to move, Red does not violate the rule and this game can
be a draw.
Diagram 102: Red (in Capital) moves first
Diagram 103: Red (in Capital) moves first
In Diagrams 102 and 103 neither side violates the rule and the games
can be ruled as draws.
Diagram 104: Red (in Capital) moves first
The Black Rook perpetually threatens to checkmate and the Red Pawn
perpetually tries to sacrifice. Neither side violates the rule
and the game is a draw.
Appendix: Example of Perpetual Chase
Red keeps moving its Pawn to keep the Black Knight "unprotected".
This constitutes the Red Rook perpetually chasing the unprotected
Black Knight. Red is violating the rule.
Example of Non-Perpetual Chase
Each of Red Rook's move is threatening the Black Cannon but the
Black Cannon does not try to escape or seek for protection.
This is not a perpetual chase and does not violate the rule.
Example of Mutual Perpetual Chase
Red's R4-2 is to allow the Rook on the 6th file to chase
the Black's Cannon on the 9th file. In the next move, R4+2, Red
is using the Rook on the 4th file to chase the Black Cannon on the
9th file. This is two pieces perpetually chasing a piece.
As to the Black side, each time it moves the Guard it is threatening
the Red Rook on the 6th file with a Cannon. This is a perpetual chase.
Since both sides violate the rule, the game will be a draw if neither
side wants to change its move.