The appropriate ratio column is chosen on the Ground Combat table and the die is rolled. The cross-indexed result is a ratio of attacker to defender losses. Supply is determined near the end of the sequence of play by simply tracing a supply line from a home base to ground units through sea areas under friendly control. Half the units in any group out of supply are eliminated. Allied units can be aerially supplied.
Naval units can apparently remain at sea between turns.
Lastly, there is the now-infamous volcano rule. Victory is determined by assigning points to unit losses and control of Guadalcanal, Bougainville, Buna and Port Moresby by turn. There is a remarkable level of depth to this game and some interesting chrome that did not require myriad special rules. The bloody ground combat rules recommend the Allied player land as many troops as possible on Guadalcanal as they will be attrited. One of the challenges of the campaign that is difficult to represent in the game is the historical Japanese Army lassitude to the initial Guadalcanal landing because of faulty intelligence about the number of Americans landed.