P.T.O. IV (Pacific Theater of Operations IV), released as in Japan, is a World War II-themed strategy for the PlayStation 2 and PC produced by Koei. It focuses on naval combat in the maritime theaters of World War II, encompassing the Pacific Ocean, Mediterranean Sea, Atlantic Ocean, and Indian Ocean, with the option of playing as one of four major maritime powers of the time: Germany, Japan, the United Kingdom, or the United States. P.T.O. IV is the latest game in Koei's P.T.O. series. Gameplay Modes There are two modes of gameplay: Scenario and Campaign. The former involves fighting historic naval engagements as either the attacker or defender with the option to continue in campaign mode if certain conditions are met to emerge victorious. If the player starts with the latter, the objective is to achieve victory for their chosen nation and alliance by controlling as many of the 50 regions into which the world's oceans and sea lanes are divided into as possible. Campaigns start either with the initial outbreak of World War II in September 1939, or after the Japanese attack on Pearl Harbor in December 1941. If the player commands the Imperial Japanese Navy, he can choose whether to attack Pearl Harbor or not. Campaigns occur in two phases: Strategic and Tactical. The Strategic phase involves long term planning of the campaign and deployment of forces. At the beginning of the month, objectives and progress towards meeting them are evaluated or set. If a given objective is met in a timely manner, additional money is earned by the player. Based on where the targeted region is located, at least a month is required to complete the objective. Commanders may be awarded with a Golden Anchor, a Silver Anchor or a certificate as a reward for their actions during these invasions. Resources can be allocated towards ship and aircraft production, R&D, or to other allies as material assistance, which may or may not be reciprocated in kind the next turn depending on the ally's resources. Ships can be organized into fleets and transferred to regions. Aircraft can be assigned to airfields or aircraft carriers, or airfields can be built in regions. After this phase is complete, the Tactical phase occurs. This involves ship movement from region to region and combat if opposing fleets encounter each other at sea (opposing fleets are moving from adjacent regions towards each other)