27. When a Rook is confined by a Cannon and cannot move away from a line, the Rook's move within this line cannot be considered a chase. Also an attack with a Rook on this confined Rook is not considered a sacrifice. Therefore, the attacking Rook cannot keep chasing the confined Rook. If one of the moves of the confined Rook is protected, this Rook can be perpetually chased. A Knight or a Cannon cannot perpetually chase a confined Rook, disregard whether the confined Rook is protected or not. (See examples from Diagram 63 to 66)

Diagram 63: Red (in Capital) moves first

C8+3 r5+1
C8+1 r5-1
C8-2 r5+2
C8+3 r5-3
C8-1 r5+1

Explanation:

Since the Black Rook is confined to the center file, the Rook cannot be considered as perpetually chasing the Red Cannon. If neither side wants to change the move, this game is a draw.

Diagram 64: Red (in Capital) moves first

R8+4 r5+4
R8-4 r5-1
R8+1 r5+1
R8-1 r5-1
R8+1 ....

Diagram 65: Red (in Capital) moves first

R2+2 r6+1
R2-1 r6+1
R2-1 r6-1
R2+1 r6+1
R2-1 ....

Explanation:

In Diagrams 64 and 65, the Black Rook is confined by the Red Cannon and cannot leave the fourth file. Therefore, the Red Rook is perpetually chasing the Black Rook and that is a violation of the rule.

Diagram 66: Red (in Capital) moves first

R32 r87
R23 r78
R32 r87
R23 r78
R32 ...

Explanation:

One of the Black Rook's moves is protected, therefore, Red Rook's attack should not be considered perpetual chase. If neither side changes, this game is a draw.