Area rules I correspond to rules formerly used in China. A player gains points by cutting his opponent into as many separate groups as possible, so there tends to be lots of cutting and fighting.
Area rules II are equivalent to the rules followed in China now, except that China does not use the super-ko rule (rule 4).
Area rules III adjust the score by one point when White passes first. This eliminates the one-point difference between area and territory rules that arises about half the time in even games from Black's having played an extra stone.
Territory rules I give the same result as area rules III, provided no unwarranted passes are made before the end of competitive play. The main differences from traditional territory rules are that surrounded territory is counted in seki positions, and life and death are always settled through actual play.
Territory rules II are contrived so as to nullify territory gained in a seki. Immortal stones cannot be captured even if the attacker makes consecutive moves and the defender always passes.
Territory rules III give the same result as area rules II by ensuring that there are equal numbers of black and white stones on the board after prisoners are filled in. Although Ikeda did not include territory rules III in his formulations, it is a natural addition.
By having the players compete to be first to pass, territory rules I and area rules III introduce an element of skill not found in traditional territory or area rules. Territory rules III and area rules II avoid introducing this new element.
None of these rules make any provision for removing dead stones without further play at the end of the game. As Ikeda mentions in Part II, however, this can be done by mutual agreement after both sides have passed.