Xiangqi has the unique rule that the two Kings may not stay along the same vertical line, unless there is at least one other piece between them. This enables the King to support other pieces at times, in attacking the enemy camp. It could play an important role in the intercepting forces in delivering a checkmate. In diagrams 1, 2 & 4 the only spot of escape for the Black King is denied by the Red King. In diagram 3, the central Black Adviser is pinned down by the Red King and, is thus unable to parry the check by going down to the spot B60. This pattern of checkmate is termed “对面笑” in Chinese, meaning ‘laughing face to face’ literally. I prefer to call it the “Royal Checkmate”.
AF: Cannon+Adviser
I F: King
AF: Pawn
I F: King (+ the Black Advisers)
AF: Horse
I F: King (+ the black Advisers)
AF: Chariot
I F: King (stops Black from playing A5-6)