The 5th Fleet is a hex-based strategical wargame based on the board game 5th Fleet. The game is designed for two players which both take the side of a war party - in matches of a larger scale one war party can include several different countries. The gameplay is strictly turn-based and every day is divided into six rounds (three for each player). Every turn is divided into three phases: submarines, ships and aircraft.

During the phases the players use two different map screens for their planning: the strategic map shows the whole operational zone divided into several areas and the tactical map offers a closer look over one area. The basic orders the players have to give are moving (marking a unit and choosing the goal hex) and attacking (choosing which weapon is used on what target). During longer matches it is also important to take care of replenishment. While naval units have to be moved on the tactical map the players can use the strategic map to plan aircraft movement. As usual for these kind of games everything is represented with abstract symbols on the map.

In single player the game features ten scenarios set in the Indian Ocean or the Persian Gulf with increasing difficulty. There the player takes the role of the American fleet and mostly fights against Russia.